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No. 19Theme:Lung protective ventilationopportunities in critical care patientsPAGE 2Neurally Adjusted VentilatoryAssist: The First Annual NAVANordic Summit MeetingA summary of experiences and casesPAGE 16Implementing NAVA and Edimonitoring as lung protectiveelements in a regional hospital ICUDr Jim Ruddy at Monklands Hospital,Glasgow, Lanarkshire, ScotlandPAGE 22Interdisciplinary implementationof Neurally Adjusted VentilatoryAssist – Robert Wood JohnsonUniversity HospitalKumar DeZoysa, RRT; JagadeeshanSunderram, MD; William Twaddle, RRT;Dana Saporito, RRT; Jacqueline Williams-Phillips, MD; Gerald Schlette, RRT; andDerikito Servillano, RRTPAGE 26Implementation of a seamlesssolution for bedside qualityventilation therapy in critical carepatient transports and MRScott Slogic, RRT, RCP, Director of LifeSupport, and Clinical Educator MatthewMcNally, RRT at Dartmouth-HitchcockMedical Center, New Hampshire, USAPAGE 34Peri-operative ventilation– What criteria are important forthe widest range of patients?Dr Javier Garcia Fernandez, The UniversityHospital of La Paz, Madrid, SpainPAGE 4Lung Protection Symposium andWorkshop Summary with focus onLung Recruitment and Neurally AdjustedVentilatory Assist - NAVAThe Prince of Wales Hospital, Hong KongPAGE 38

2 | Critical Care NewsIntensive care physician participants from over 4 countries at the Lung Protective Symposium and Workshop in Hong KongLung protective ventilation opportunitiesin critical care patientsFor the past 19 years, Critical Care News has always maintained a focus on lung recruitment andlung protective ventilation strategies. There have been many developments since the landmark ARDSstudy by M Amato et al in NEJM 1998. In this issue, Dr Fernando Suarez Sipmann provides an excellentoverview and observations of developments in lung recruitment during the past decade, which waspresented at an intensive care symposium in Hong Kong.Critical Care News has also been continually reporting about Neurally Adjusted Ventilatory Assist - NAVA,since 2006. Many of the physicians using NAVA that have been featured in earlier issues of the magazinehave recently published scientific studies on NAVA. These include Dr Karl Erik Edberg and colleagues inCCN issue 13, September 2006 from Gothenburg, Sweden who have now published an observationalstudy of NAVA in 21 children (Pediatr Crit Care Med 2009; Jul 9) and Drs Brendan O’Hare, Maureen Healyand colleagues in CCN issue 15, September 2007 from Dublin, Ireland, that have published a prospectivecrossover comparison of NAVA and Pressure Support in 16 pediatric and neonatal patients (Pediatr CritCare Med 2009; Jul 9). The use of NAVA in congenital heart diseased infants as shared by Dr Limin Zhuand colleagues at Shanghai Children’s Hospital was featured last summer in CCN issue 17, and theyhave recently published their experiences with NAVA in these infants undergoing cardiac surgery.The list of scientific publications on NAVA and Edi monitoring continues to grow, as the methodologyis now being applied by critical care clinicians in over 30 countries worldwide. The latest updatedreference list of NAVA scientific publications may always be found at www.criticalcarenews.com.

Critical Care News | 3Lung Protection by means of lungrecruitment and NAVA – HongKong Symposium and WorkshopThe third Lung Protection Symposiumand Workshop at the Prince of WalesHospital in Hong Kong was an educationalopportunity for over 100 attendingclinicians from Hong Kong, Macao,Taiwan and the People’s Republic ofChina. The lecture faculty includedinternationally known physician andresearcher Dr Fernando Suarez Sipmannfrom Madrid, who presented two differentcurrent views on protective ventilation– one of “permissive atelectasis” andthe “Open Lung approach”. Dr CharlesGomersall, another internationally knownspeaker and researcher, lectured onNeurally Adjusted Ventilatory Assist. Hehighlighted the clinical application ofNAVA, and the lung protective potentialof patient-ventilator synchrony. He alsopresented a number of NAVA patientcases from his own experience, includingintermittent dyspnea and Cheyne-Stokes.The first annual NAVA NordicSummit MeetingTwenty-six intensive care clinicians fromthree countries gathered in Stockholmfor the first annual NAVA Nordic SummitMeeting. The purpose of the meetingwas to provide a forum to share NAVAclinical experiences and cases, and tobuild a foundation for sharing ideas andcooperation with NAVA in the future.Intensivist Dr Lisa Seest Nielsen fromKölding, Denmark, shared experienceof NAVA in adult patients. The regionalRyhov hospital of Jönköping, Sweden,started using NAVA in September 2008,and Dr Armela Khorassani shared casesand experience and data collected over9 months, with over 22 NAVA patientsranging from 10 to 89 years of age. Shedescribed some of the benefits withNAVA experience to date to includeavoidance of tracheotomy in 5 patientsand probably shorter hospitalization in 7 ofthe 22 patients. Dr Ninna Gullberg of thePICU of Astrid Lindgren Children’s Hospitalin Stockholm shared her experiencesof NAVA in many patient treatments,and presented a special case report ofNAVA in a critically ill 6 week old infant.Dr Jim Ruddy, Monklands Hospital,ScotlandImplementing NAVA and Edimonitoring as lung protectiveelements in a regional hospital ICUThe 6 bed ICU of Monklands Hospitalnear Glasgow, Scotland, treats awide variety of almost 400 medicaland surgical ICU patients each year.These challenges have been met by astaff of five intensive care consultantsthat have been implementing lungprotective strategies on a routine basis.They implemented NAVA and Edimonitoring at the beginning of this year.Their very first patient experience withNAVA was a worst-case scenario – apatient that had been on mechanicalventilation for 62 days. (See thisNAVA patient case report at www.criticalcarenews.com) Intensive carephysician Dr Jim Ruddy shares hisobservations and experiences of bothNAVA and Edi monitoring, which arebeing utilized on a regular basis.William Twaddle, RRT andJagadeeshan Sunderram, MD in theRobert Wood Johnson MICUInterdisciplinary implementationof NAVA at Robert WoodJohnson University HospitalThe award-winning Robert WoodJohnson University Hospital andits associated Bristol-Myers-SquibbChildren’s Hospital have been atthe forefront in implementing newinnovations in patient care. The institutionwas among the very first in the UnitedStates to introduce NAVA to theMedical ICU, Surgical ICU, Cardiac ICUas well as the Pediatric and NeonatalICUs. Members of interdisciplinaryteams share their experiences, andsome ideas and plans for the future.Transporting patient from MR to PICUat Darthmouth-Hitchcok Medical CenterImplementation of a seamlesssolution for bedside qualityventilation therapy in critical carepatient transports and MRThe internationally renowned andstate-of-the-art Dartmouth-HitchcockMedical Center in New Hampshire inthe United States faces the challengesof caring for 85 critical care patientson a daily basis. The Respiratory Caredepartment sought and found solutionsto provide uninterrupted ventilationand continuity of care to all of thesecritical care patients, in all areas of themedical center, including the sickest andmost fragile patients in the hospital.Peri-operative ventilation - whatcriteria are important for the widestrange of patients and why?The final feature of this issue highlightsthe ideas and reflections of Dr JavierGarcia Fernandez of the La Paz UniversityHospital in Madrid. He discussesthe importance of certain technicalpossibilities in anesthesia machines,enabling safe ventilation of a wide rangeof patients in the operating room.

4 | Critical Care NewsParticipants registering for the three day Lung Protection Symposium and WorkshopLung Protection Symposium andWorkshop Summary with focus on– Lung Recruitment and NeurallyAdjusted Ventilatory Assist - NAVAOver 100 participating physicians from Hong Kong, Macao, Taiwan, and the People’s Republic ofChina attended a three day Lung Protection Symposium and Workshop at the Prince of Wales Hospitalin Hong Kong in February, for an educational opportunity to learn about lung recruitment and NAVA.The activity, which was the third Lung Protection Symposium hosted by the Prince of Wales Hospitalin recent years, featured a faculty of globally renowned guest speakers including Dr Fernando SuarezSipmann of the Fundación Jiménez Díaz Hospital in Madrid, and Dr Charles Gomersall of the Princeof Wales Hospital in Hong Kong.The participants were welcomed officially by CM Leung, CEO of Maquet Hong Kong, who co-hostedthe activity together with the Prince of Wales Hospital. The three day program featured lectures bythe guest speaking faculty, followed by two days of hands-on workshop in the physiology laboratory.

Critical Care News | 5Lung recruitment – the concepts, the practical approach,and ideas about how to improve the strategy at bedsideFernando Suarez Sipmann of HospitalFundación Jiménez Díaz in Madrid, has aprimary interest in research in mechanicalventilation and respiratory physiology, andhas been working in the areas of researchand treatment of patients with lungrecruitment since 1996. He introducedhis presentations as lectures on lungprotective ventilation, especially lungrecruitment and PEEP as closely linkedelements of a lung protective strategy.Dr Suarez Sipmann highlighted theclassic pressure-volume curve inrelation to ventilator induced lung injuryas a frame about how application ofmechanical ventilation has an impact onpatient outcome. Theoretically, the PVcurve shows all of the possibilities toventilate a specific lung mechanically.Given the different combinations,exceedingly high volume or pressurein the right upper area of the curve,subjects the tissue to mechanical stress,with risk of rupture of alveolar walls.Ventilating at those pressures overtime can aggravate respiratory failure.The other extreme is the region of lowvolume and pressures, down left wherethe lung tends to collapse. Mechanicalventilation forces bring several dangersin the collapsed region, principally stressby continuously opening and closingsmall airways and alveoli. Dr SuarezSipmann highlighted the concept ofventilating ideally in the safe zone, i.e.away from the area of over distentionand away from the collapsed zone.Landmark lung recruitment studyDr Suarez Sipmann referred to theauthors that first introduced the term“lung protection” in clinical practice,in the study by Amato et al in 1998 inthe New England Journal of Medicine,which was a turning point in mechanicalventilation. The authors combined allthose concepts that were thought atthat time to have a protective effect onthe lung: to reduce tidal volume andplateau pressure allowing CO 2 to riseDr Fernando Suarez Sipmann of Madrid lectured on lung recruitment concepts andbedside strategypreventing the lung from overdistentionand to apply higher levels of PEEPbased on the lower inflection point ofthe PV curve to minimize collapse, andputting all of these strategies togetherintroducing the term of lung protectiveventilation strategy. A reduction inmortality of up to 30% in patients inthe protective strategy, compared to aconventional group in this study taughtthat the way the physician turns knobson the ventilator, without the need ofexpensive drugs and treatments, has initself an impact on patient’s outcomes,according to Dr Suarez Sipmann.He stated that this landmark study wasfollowed by a number of other clinicalstudies that tried to reproduce thebenefits of lung protective ventilationstrategies, some with positive results,some negative. The most important onewas by the NIH group in the NEJM,which is also called the ARDSNettrial. After enrolling 800 patients thisstudy could demonstrate that simplyadjusting one intervention – limitingthe tidal volume – had a positiveimpact on patient’s outcome.

6 | Critical Care NewsFernando Suarez Sipmann of Hospital Fundación Jiménez Díaz in MadridProtective ventilation –two different viewsDr Suarez Sipmann illustrated anexample of a patient with ARDS witha CT scan showing aeration of uppernon-dependent regions combinedwith extensive collapse in the dorsaldependent lung regions. This is thescenario for a heterogeneous distributionof ventilation with the boundary regionsof aerated and collapsed regions,submitted to a high mechanical stress.He stated that when facing such acondition there are two different viewsof how to best manage this patient.One current view may be termed as“permissive atelectasis”, This view isrepresented by the ARDSNet approach,where the ventilation strategy isadapted to the aerated lung which dueto its reduced size has been termedthe baby lung. In this approach, it isrecommended to reduce tidal volumeto minimize overdistention but tolerateatelectasis, in the hope that thecollapsed lung will recover over timeand that the mechanical stress to theaerated lung can be minimized.The other current view of managing thiscondition is what Dr Suarez Sipmanncalls “the Open Lung approach”, whichis a ventilation strategy aimed atactively restoring and maintaining thesize of the ventilated lung. This currentof understanding emphasizes thatatelectasis is a pathological conditionof the lung, per se harmful. Theirpresence results in poor oxygenationand mechanics, a more heterogeneousdistribution of tidal ventilation facilitatingthe overdistension of the aeratedregions and promoting cyclic openingand closing of the boundary regions.Importantly, both views aim at protectingthe lung sharing the idea of limitingoverdistension and tidal recruitment.In the Open Lung approach accordingto Dr Suarez Sipmann the majordifference resides in the attemptto re-expand the collapsed lung bymeans of a recruitment maneuver and,specifically, in the use of PEEP whichin such a strategy aims at stabilizingthe recruited lung at end-expiration.According to Dr Suarez Sipmann, onlytidal volume limitation might not beenough to fully protect the lung fromventilation induced lung injury. Recent

Critical Care News | 7level of PEEP must be found that is ableto maintain tidal ventilation exactly atthis region where collapse is avoided,according to Dr Suarez Sipmann.Dr Suarez Sipmann illustrated changesin lung aeration in the recruitmentprocedure by means of a PV curvewith inspiration and expiration ofa sick ARDS patient, presentedas CT scans, showing that settingventilation along the inspiratorylimb of the PV curve is associatedto the the presence of collapse.Dr Suarez Sipmann stated that ifthe areas of the lung that are closedare recovered and stabilized, theywill increase the functional lungunits improving gas exchange,and lung mechanics and moreimportantly contributes to minimizeventilation induced lung injury.Dr Suarez Sipmann has been involved with research and clinical application of lungrecruitment manuevers for many yearsstudies have shown that in a certainpopulation of ARDS patients with higheramounts of collapse, tidal volumelimitation as recommended by theARDSnet approach resulted in areas ofoverdistention that appeared as areasof excessive aeration in CT scans atend-inspiration. Dr Suarez Sipmannreferred to the study by Terragni et alin AJRCCM 2007, which illustrated thatthe two main mechanisms of ventilationinduced lung injury, overdistention andtidal recruitment, could be presentwhen applying the ARDSnet strategy.Therefore, we cannot assume that justlimiting tidal volume to a certain extent, isenough to protect the lung in all patients,according to Dr Suarez Sipmann.Definition of Lung Recruitmentand procedure in theoryDr Suarez Sipmann defined lungrecruitment as the “re-expansion ofpreviously collapsed lung units bymeans of a brief controlled increasein transpulmonary pressure thatresults in an instantaneous changeof the lung’s morphological andphysiological condition”. He highlightedthe concepts of a controlled increasein transpulmonary pressure, so thatthe physician is aware and in control ateach step of the recruitment process.In terms of re-expanding the lung andkeeping it open, Dr Suarez Sipmannexplained that the objective in this stageof recruitment is to shift ventilation fromthe inflation to the deflation limb of thePV relationship, i.e. establishing tidalventilation in the outer deflation limb,around the point of maximum curvature,away from the collapse region. To achievethis the lung must first stay a brief periodon the overdistention part of the curve,which is the only way to have accessto the deflation portion where we wantto establish ventilation. The minimumDr Suarez Sipmann further illustratedthe differences between establishingventilation in the inflation as comparedto the deflation PV limb. In the samepatient with pulmonary ARDS, stepwiseincreases of 2 cm H 2 O of PEEP whilemaintaining the same tidal volumeand respiratory rate provided modestchanges in oxygenation and compliance.However when PEEP steps werereduced after recruitment, maintainingthe same ventilatory settings, therewas a marked increase in oxygenationand compliance until the critical level ofPEEP, the closing pressure was reached.This means that provided the patient canbe effectively kept at this level, ventilationcan be maintained at lower pressuresand tidal volumes over the long term,in a better physiological condition, aspresented by Dr Suarez Sipmann.Different types of lungrecruitment maneuvers?Dr Suarez Sipmann stated that lifeis not simple at the bedside, andrecruitment is not a simple procedure.There is an ongoing debate on whichis the best recruitment maneuver, andpublished data on patient outcome arestill not available. Since the landmarkstudy by Amato et al in NEJM 1998, aremarkably long list of clinical studies on

8 | Critical Care Newslung recruitment have been published.According to Dr Suarez Sipmann, lungrecruitment must be aimed at recruitingas much lung as possible to efficientlyestablish a lung protective strategy.When only transient improvementsin oxygenation or lung mechanicsare sought recruitment is reduced toa matter of “lung cosmetics” not arational ventilation strategy. In sucha context its use is not justified.The group of Amato has published animportant recent study (Borges, AJRCCM2008) where many important conceptsof lung recruitment were described,and where they validated the criterionof PaO 2 for defining a fully recruitedlung in 25 ARDS patients. Wheneverthe PaO 2 was less than 350, there wassignificant collapse seen on the CT scan.A sequential recruitment maneuver withdifferent levels of pressure was applied,and in patients who were fully recruitedaccording to PaO 2 criteria (PaO 2 /FiO 2 >300 mmHg) and CT criteria also showedan increase in static compliance of 15%.From the many published clinicalstudies describing different lungrecruitment maneuvers, Dr SuarezSipmann emphasized primarily threetypes of recruitment maneuvers,including the most frequently describedin literature; the CPAP maneuver, or theso called 40/40 maneuver. Although theCPAP maneuver is the most frequentlydescribed in the literature, in up to40-50% of the studies, Dr SuarezSipmann believes that this is not thebest strategy and should not beused. The patient remains in apneaand maximal level of pressuresare maintained for the entireperiod significantly increasingthe hemodynamic effects.He strongly recommends a cyclingrecruitment maneuver in Pressurecontrolled ventilation. He describedtwo types of cycling maneuvers, onecalled single pulse in Pressure Controlventilation, which is recommendedfor patients in less severe disease, forexample in postoperative patients wherepressures can be increased in two orthree short steps to the recruitment level,generally in the range of 45 cm H 2 O.The other cycling maneuver consists inapplying several sequential incrementalPEEP steps, where the maneuver canbe individualized to the particular patient.From baseline, a level of PEEP is selectedto be high enough to maintain the entirerecruited lung stable usually in the rangeof 25 cm H 2 O in ARDS patients, beingthis the level of PEEP maintained alongthe recruitment sequence. As shown byBorges et al, different recruitment levelscan then be explored by increasing PEEPin 5 cm H 2 O steps above baseline whilemaintaining a fixed inspiratory pressuregradient for 2 minutes and returningto baseline PEEP after each step forevaluation. If Open Lung criteria havebeen obtained according to oxygenationand/or lung mechanics no furtherlevels of pressure need to be explored.If not, the next level of inspiratoryrecruitment pressure is explored.Dr Suarez Sipmann described timedependency as a factor, with the needto apply a certain amount of pressurefor a certain amount of time. There isa minimum threshold pressure, thecritical opening pressure, that has tobe overcome otherwise no significantrecruitment effect, independently ofthe time it is applied can be expected.As the lung gets sicker, more timeand higher pressure are neededaccording to Dr Suarez Sipmann.Higher pressures in ARDS tooptimize lung recruitment in ARDSDr Suarez Sipmann illustratedthe complexity of the situation inregard to the heterogeneity of theARDS lung: lungs with significantcollapse show a vertical gravitationalgradient of opening pressures, whichmeans that the alveoli at the dorsal,dependent region require much higheropening pressures than those in theventral non-dependent regions.Dr Suarez Sipmann referred to therecruitment pressures in ARDSlungs reported by Borges et al inthe AJRCCM in the distribution ofopening pressures in severe ARDSpatients. Although over 50% werefully recruitable with pressures of 45cm H 2 O, the most diseased lungsrequired up to 60 cm H 2 O in somecases. According to Dr. Suarez Sipmannthis study highlighted the importanceof individualizing the recruitmentpressures to each particular conditionlooking for the minimum pressurethat results in full lung recruitment.Dr Suarez Sipmann went on to illustratethe occurrence of important uncontrolledincreases in airway pressures associatedwith routine interventions such as bagging.He showed an example where baggingpressures were recorded with repeatedpressure peaks over 50 cm H 2 O –with oneof the bags resulting in pressures over80 cm H 2 O. The effects of handbagging,which occurs frequently in routine clinicalpractice, can sometimes result in muchhigher pressures than those reachedduring controlled recruitment maneuvers.Lung recruitment side effectsDr Suarez Sipmann reported that in asystematic review in AJRCCM 2008 of 40different studies with over 1200 patients,in different situations submitted to lungrecruitment, the number of side effectsreported are surprisingly low eitherbefore, during or after the recruitmentprocedure. He stated that beforepressurizing the patient, a good volemicstatus and a stable hemodynamiccondition must be confirmed. Heoutlined that the hemodynamiceffects of lung recruitment are mainlycaused by a decreased venous return,increased right ventricular afterloadand compromised left ventricular fillingdue to ventricular interdepence. Themajor effects include reduced cardiacoutput, and reduced systolic arterialpressure. “However, when performing arecruitment maneuver in a protocolizedway most of the time these side effectsduring recruitment maneuvers are smallin magnitude, preventable and selflimited”, stated Dr Suarez Sipmann.He went on to explain howhemodynamics depends on lungcondition and volemia. Dr Suarez Sipmannexplained: “As compliance decreases,the transmission of alveolar pressure tothe pulmonary circulation also decreasesso that sicker patients needing higherrecruitment pressures are more protectedagainst hemodynamic side effects.

Critical Care News | 9Mr Arne Lindy of Maquet Critical Care, thanking Dr Suarez SipmannDr Suarez Sipmann outlined that thetype of recruitment maneuver isan important factor in influencingthe hemodynamic response. Thiswas systematically assessed in anexperimental study where differentlung injury models where submitted todifferent recruitment maneuvers by DrMarini’s group. They could show thatsustained inflation (the 40/40 maneuver),caused the most important decreasein cardiac output. Best tolerated wasa cycling Pressure Control maneuver,with maximum decreases of 20 - 30%in cardiac output, which recoveredto normal within a few minutes afterthe recruitment maneuver. Dr SuarezSipmann stated “The 40/40 is not thebest approach, the pressures are notenough, patients are apneic, so thethorax is continuously pressurized,causing major hemodynamic effects.”In terms of hemodynamic managementin lung recruitment, Dr Suarez Sipmannrecommended a protocol of baselineventilation, and an adequately resucitatedpatient with stable cardiac output andmean arterial pressure. He outlinedone of his ongoing studies, looking atthe impact of right ventricular and leftventricular output during recruitmentmaneuvers in ARDS patients.Rationale for using Pressure Controlventilation during recruitmentAccording to Dr Suarez Sipmann,the rationale for using PressureControl during recruitmentincludes the following factors:– Strict control over inspiratory pressures– No pendelluft phenomenon:new recruited regions alwaysreceive fresh gas from the ventilator– Cycling allows pressurerelief during expirationThe role of PEEPHe went on to state that the NIH trial paidless attention to the importance of PEEP,which was selected as the lowest possiblelevel for a needed FiO 2 to achieve a specificoxygenation target. He stated that thistable has no physiologic rationale whichis one of the major critiques to the NIH–ARDSNet trial according to Dr Suarez.Dr Suarez Sipmann also referred to 3fairly recent studies focusing on highversus low PEEP; the ALVEOLI (U.S.study) reported in NEJM 2004, theLOVS study (Canada) reported in 2008,and the EXPRESS study from France,also reported in 2008 both in JAMA.He commented: “There are now threelarge randomized clinical trials thatcould not demonstrate a clear benefitof higher levels of PEEP on survival”.There was however, a trend to abeneficial effect of the use of higherlevels of PEEP and clear benefits onimportant secondary endpoints, thatsupport the recommendation of usinghigher levels of PEEP. Except for theExpress study, PEEP was selectedaccording to a PEEP/FiO 2 table, onlylooking at oxygenation. This resulted ina constantly higher plateau pressure inthe high PEEP group as compared tothe lower PEEP groups. According to DrSuarez Sipmann the lack of control ofthe increase in plateau pressures mayhave offset the potential benefits of theuse of higher PEEP in these studies.

10 | Critical Care NewsClinical application of Neurally Adjusted Ventilatory Assist – NAVADr Charles Gomersall of the Intensive Care Department of the Prince of Wales Hospital in Hong Kong, presented the concept and clinicalapplication of NAVADr Charles Gomersall of the IntensiveCare Department of the Prince of WalesHospital in Hong Kong has been familiarwith the clinical application of NeurallyAdjusted Ventilatory Assist, or NAVA in hisintensive care department since late 2007.He started his presentation by presentingthe physiological concept of NAVA,where a patient’s neural respiratorysignals, or Edi – electrical activity of thediaphragm, were used to trigger theventilator according to the patient’s ownrequirements. Dr Gomersall outlinedthe differences in the concept of NAVAcompared to conventional pneumaticmechanical ventilation by explaining:“Conventional ventilator technology usesa pressure drop or flow reversal to initiatethe assist delivered to the patient. WithNAVA, the electrical discharge of thediaphragm is captured by an Edi catheterfitted with an electrode array. The signalis then passed to the ventilator, whichexecutes both triggering and flow controlin proportion to the received Edi signal.”Practical set up of NAVADr Gomersall briefly reviewed thecomponents needed for NAVA, consistingof ventilator, software, NAVA module,and Edi catheter with 10 electrodes. Hereviewed the NEX measurement formulaand procedure to estimate the insertionlength of the Edi catheter needed. DrGomersall went on to explain: “Whenthe Edi catheter is in place, you seeesophageal ECG – an added benefit ofthe Edi catheter. I am waiting for a broadcomplex tachycardia, so that I can saythat I diagnosed a type of tachycardiafrom a nasogastric tube and ventilator.Verify the position of the Edi catheterby means of the ECG waveforms.”Dr Gomersall also presented informationabout what NAVA levels entail. Hedescribed the NAVA level as anamplification factor. In the NAVA modethe SERVO-i will amplify each Edi sampleas determined by the set NAVA level,after the following formula: P=NAVAlevel x (Edi signal-Edi min) + PEEP. The

Critical Care News | 11amplification depends on the selectedNAVA level and results in a smoothlyrising pressure. The shape of thepressure curve mirrors the Edi signal untilthe Edi signal drops to 70% of peak Edi.The ventilator cycles to expiration, andthe pressure will drop to the set PEEPlevel. Dr Gomersall explained: “Not onlydoes NAVA give you a way of triggeringthe ventilator, the profile of the breathis determined by the patient’s effort”.To address the question if NAVA unloadsrespiratory muscles, Dr Gomersallreferred to the literature, where a studyin healthy volunteers comparing 0 andhigh levels of NAVA support (Sinderbyet al, Chest 2007; 131(13): 711-717),NAVA allows the patient to take thesame tidal volume while making lesseffort, according to Dr Gomersall.Dr Gomersall also showed data from apatient in his intensive care unit, wherethe NAVA level was 1.5 cm H 2 0/µv,increasing the NAVA level to 3 cm H 2 0/µv resulted in a reduction in Edi withmaintained tidal volume. This indicatesthat the respiratory work was takenover from the patient by the ventilator.Ventilatory dyssynchronyand its consequencesDr Gomersall addressed the subjectof ventilatory dyssynchrony and itsconsequences, referring to Thille et al(Intensive Care Med 2006; 32(10):1515-1522) where the authors studied 62patients triggering the ventilator. Theyinvestigated the impact of dyssynchronyin assist controlled and PressureSupport ventilation. The main outcomeof the study was that the length ofmechanical ventilation was muchextended in patients with dyssynchrony.He summarized that from an outcomeperspective, patients with an asynchronyindex higher than 10% were likely to havea longer time on mechanical ventilationand a higher incidence of tracheostomy.Does NAVA have an effecton asynchrony?Dr Gomersall addressed this questionby presenting some of the original preclinicalscientific studies, comparingNAVA and Pressure Support ventilation,in low, medium and high levels. He said:“It is difficult to set equivalent level ofNAVA to Pressure Support, but if youused peak pressure, the waveforms aredifferent, and pressure time curve isdifferent in NAVA. Tidal volumes don’tchange much with NAVA. In terms ofpeak airway pressure and tidal volumethere is a contrast between NAVA andPressure Support modes”, accordingto Dr Gomersall. “As you increase theNAVA level the peak airway pressureand the tidal volume doesn’t changemuch. When you increase the inspiratorypressure level in Pressure Support, thepeak airway pressure and tidal volumesincrease markedly. Pressure time productof diaphragm or work of breathing ofdiaphragm, with NAVA as you increaselevel, the work goes down. With PressureSupport, it falls initially, but then rises.”In terms of trigger delay, with NAVAthe trigger delay is not really a factor,as presented by Dr Gomersall. WithPressure Support the trigger delayincreases as you increase the levelof Pressure Support, reflectinghyperinflation induced trigger load.According to Dr Gomersall, theexplanation is that what happens inPressure Support is that as the pressureand therefore the tidal volume goes upthere is more gas trapping, resultingin trigger delay. On one hand workof breathing decreases by increasingPressure Support, on the other handit is harder to trigger as PressureSupport levels are increased.Human dataDr Gomersall reviewed a study byColombo et al consisting of 14 patientsin Pressure Support and NAVA, withequivalent levels of Pressure Support andNAVA on maximum voluntary breaths.Edi was suppressed in Pressure Supportcompared to NAVA. In high levels ofPressure Support the triggering wasnot effective. Diaphragmatic activityin Pressure Support was found tobe variable, and tidal volume to beconstant in Pressure Support. In thesame study NAVA provided variableEdi and variable tidal volume, as thepatient is controlling tidal volume muchmore effectively than in PressureSupport, according to Dr Gomersall.He also stated that the grouped datafrom this study showed that neuralinspiratory time does not change withlevel of support. “Inspiratory timeincreases in Pressure Support as youincrease level of Pressure Support.Neural expiratory time and flow timegoes up in Pressure Support. Thereason for neural expiratory timeincreasing in increasing levels ofPressure Support, is that the inspiratorytime is being artificially prolonged,the patient is unable to exhale whenthey desire, and expiration is delayed,”as explained by Dr Gomersall.He summarized the study by statingthat using a cut-off of asynchrony indexgreater than 10, five patients in thePressure Support group were found to beasynchronous, but none in NAVA group.NAVA experience in clinical practiceDr Gomersall said that he did not yethave systematic data, and for thisreason preferred to present a fewpatient cases from his practice.Intermittent dyspneaThis patient case was an obese ladywith neuropathia, who was difficult towean and had intermittent dyspneaon Pressure Support ventilation.A bronchoscope was placed forobservation, and in her trachea itwas found to be moving inwards oninspiration. It revealed some collapsedown to about one-third of its normaldiameter. The patient had PEEP andPressure Support, of which somewas lost during bronchoscopy. TheICU team interpreted that therewas signal trigger delay and thatthe ventilator did not deliver breathsas fast as the patient desired.When the patient was taken off theventilator, no dyspnea occurred, howevershe was not strong enough to stay offthe ventilator for a long period of time.She was started on NAVA, whichobliterated trigger delays, and clinically

12 | Critical Care NewsDr Charles Gomersallshe was much more comfortable. Thepatient was now easily weaned on NAVA.Cheyne-StokesDr Gomersall and his colleagues haveexperienced some advantage with NAVAin the category of patients with Cheyne-Stokes respiration, with crescendodecrescendopattern of breathing in rateand depth, with periods of apnea. Heexplained: “If you ventilate these patientson Pressure Support, you get standardtidal volume for each time they triggerthe ventilator. So instead of getting acrescendo and decrescendo in rate anddepth, you get constant values, whichexacerbates the problem of apnea, sothat the ventilator, even if set at maxapnea time, goes into back-up ventilation,therefore it is difficult in getting thepatient to breathe more. If you take thesepatients off the ventilator, the issue ofapnea becomes less of a problem, butthese patients are not able to toleratespontaneous breathing for long periodsof time. In this group, when we put inthe Edi catheter and switch to NAVA, itis much easier to wean these patients,since they have control; the tidal volumeis dependent on their respiratory effort.”Dr Gomersall also illustrated experiencewith examples of ventilation in PRVC,with significant dyssyncrony betweenPRVC breaths and Edi and no correlationbetween PRVC breaths and attemptsto breathe. He added “NAVA getsperfect synchrony in these patients.In a recent patient with a flow patternthat was odd, she was attemptingto breathe between breaths withfailure to trigger; perfect synchronywas obtained in switching to NAVA.Dr Gomersall concluded his presentationby summarizing that NAVA is apromising new mode of ventilation,simple to use, and will effectively offloadrespiratory muscles. He statedthat NAVA reduces dyssynchrony.

Critical Care News | 13Hands-on physiology workshop and participant feedbackSome of the many workshop participantsThe purpose of the workshop was togive the participants the opportunitiesto perform recruitment maneuverswhile individualizing treatment tothe specific lung, with extensivemonitoring of the respiratory aswell as the hemodynamic side.On the respiratory screen, the OpenLung tool, trends on time scale onpressures, inspiratory and expiratorytidal volumes, and the inspiratorydynamic compliance and tidal CO 2elimination were utilized for lungprotective recruitment maneuvers.The workshop also gave the opportunityto observe electrical activity of thediaphragm by means of Edi signalsand to monitor patient-ventilatorsynchrony by means of NAVA.Critical Care News spoke with some ofthe participants of the lung protectivesymposium and workshop, to heartheir feedback after the sessions.Dr Dennis Kin Long Wong,Macau Government Condede São Januário HospitalI am an ICU physician and medical officertreating adult patients in a governmenthospital in Macau. I had read to preparebefore coming here to join the two day lungprotective course. We can have a real chanceto practice here to consolidate our clinicalknowledge, which is a nice opportunity for us.When returning home after theworkshop, will you be trying todo recruitment maneuvers?Yes, I will definitely try, on ARDS patientsand maybe ALI patients and some severepneumonia patients to start out with.I will start with a few patients first,we have 10 beds in our ICU which is ageneral medical/surgical/neurologicalICU. The symposium and workshop havebeen very good, I learned a lot. I wouldlike to join similar courses in the future.Dr Wong is Medical Officer at theMacao Government Hospital ICU

14 | Critical Care NewsDr Zhou Suming of The People’sHospital of Jiangsu Province, PRCDr Hsinkuo Kao and Mrs Shiu Hui Qua, from Taiwanresults at bedside. This has been avery valuable workshop for us. We seethe lung recruitment effects in ARDSpatients today, but I think we are findingthe value of recruitment maneuversin other types of patients as well.Intensivist Dr Hsinkuo Kao, andMrs Shiu Hui Qua, RespiratoryTherapist, TaiwanDr Kao: We work at the UGH hospitalin Taipei, where we currently havea 30 bed ICU, which is on the wayto increasing to 36 beds. It is amedical ICU; most patients belongto the medical care program.Are you familiar with lungrecruitment procedures?Dr Kao: Yes – we have had meetingsabout lung recruitment, and we performthese maneuvers in our patients, weselect patients with ARDS and we lookat hemodynamics as a major individualfactor in performing the maneuvers. Weknow the patients conditions and thesituation to stabilize, we perform the lungrecruitment maneuvers and we check bychest x-ray. In our department, ARDS isoften complicated by pneumonia, so thatin these patients with pneumonia relatedARDS we perform these maneuvers.How will you teach yourfellow respiratory therapistsabout lung recruitment?Mrs.Qua: As Director of RespiratoryTherapy, I have 40 RT therapists thatreport to me. We have education bycoworkers but are more interested inthis technique, and we need doctorapproval to teach the technique, in orderto support it and apply it. Educationis the first step and we have otherphysicians that perform various types ofrecruitment maneuvers in our hospital,but we know we can monitor usefulparameters with the Open Lung tooland dynamic compliance as a newelement in our treatment practice. Inthe past we have perhaps performedlung recruitment by more traditionalmethods, but it was not apparent exactlywhat was happening to our patients,and there is more data today to supportdifferent methods than in the past.Dr Kao: By using the Open Lung tool,I can see parameters that might helpme to diagnose and understand theZhou Suming, Director of ICU,The People’s Hospital of JiangsuProvince, People’s Republic of ChinaIt was the first time I have seen lungrecruitment maneuvers. We haveSERVO-i in our ICU and sometimeswe see ARDS patients, so that is thebasis of my interest in attending thisworkshop. My intensive care unit is10 beds, and it is a geriatric ICU, wesee a lot of COPD, and sometimeswe see surgical patients as well.Are you interested in NAVA?I think that has been the most interestingaspect of the workshop for me, it is veryhard for us sometimes to wait for theventilation to gather information; NAVAmight give us information at bedside.With geriatric patients and issues inregard to sleep quality at night, NAVAmight be an interesting opportunityfor us in future. This information, aswell as the lectures and questions andworkshops have been very useful.

Critical Care News | 15BiographiesFernando Suarez Sipmannconducted his initial Study ofMedicine at the University ofNavarra, Pamplona, Spain andearned his degree there in 1990.During the years of 1991 and 1996,he specialized in Intensive CareMedicine at the Fundación JiménezDiaz University Hospital of theUniversidad Autónoma in Madrid.Since then he has been workingas a consultant in Intensive CareMedicine at the same institution.He earned his PhD degree at theDepartment of Clinical Physiology ofthe University of Uppsala, Swedenin 2008. He is internationallyknown for his research in intensivecare, is well-known within thelecture circuit, and has been afrequently invited speaker, mainlecturer or chairman in internationalcongresses, symposia and othervenues during the past ten years.Dr Charles Gomersall is AssociateProfessor of the Department ofAnaesthesia and Intensive Careat the Chinese University of HongKong. He received his undergraduatetraining at the Westminster MedicalSchool, University of London. Hispostgraduate training has taken placein internal medicine at St. George’sHospital, London, in anesthesia atSt. Mary’s Hospital in London, andin intensive care at the Prince ofWales Hospital in Hong Kong.Charles Gomersall has conductedscientific research in special interestareas, which currently include triage,antibiotic pharmacokinetics andprobiotics. He is currently Editorof ICU Web. This website for ICUhealthcare professionals receivesapproximately 65000 visits permonth. Charles Gomersall has alsobeen initiator, editor and majorauthor of BASIC (Basic Assessmentand Support in Intensive Care),and the Very BASIC and Not SoBASIC courses. He is also heavilyinvolved in the CoBaTRICE project.References1) Costa EL, Borges JB, Melo A,Suarez-Sipmann F, Toufen C Jr, BohmSH, Amato MB. Bedside estimationof recruitable alveolar collapsesand hyperdistension by electricalimpedance tomography. IntensiveCare Med 2009; 35(6): 1132-1137.2) Borges JB, Carvalho CR,Amato MB. Ventilation strategiesfor acute lung injury and acuterespiratory distress syndrome.JAMA 2008; 300(1): 41-42.3) Fan E, Wilcox ME, Brower RG,Stewart TE, Mehta S, LapinskySE, O Meade M, Ferguson ND.Recruitment maneuvers for acutelung injury – A systematic review.AJRCCM 2008; 178: 1156-1163.4) Villar J, Perez-Mendez L, LopezJ, Belda J, Blanco J, SaraleguiI, Suarez-Sipmann F, Lopez J,Lubillo S, Kacmarek RM, HELPNetwork. An early PEEP/FIO2trial identifies different degrees oflung injury in patients with acuterespiratory distress syndrome.AJRCCM 2007; 176(8): 795-804.5) Suarez-Sipmann F, Bohm SH,Tusman G, Pesch T, Thamm O,Reismann H, Reske A, MagnussonA, Hedenstierna G. Use of dynamiccompliance for open lung positiveend-expiratory pressure titrationin an experimental study. CritCare Med 2007; 35(1): 214-221.6) Borges JB, Okamoto VN, MatosGF, Caramez MP, Arantes PR,Barros F, Souza CE, Victorino JA,Kacmarek RM, Barbas CS, CavalhoCR, Amato MB. Reversibility of lungcollapse and hypoxemia in earlyacute respiratory distress syndrome.AJRCCM 2006; 174(3): 268-278.7) Amato MBP, Barbas CSV, MaderiosDM, Magaldi RB, Schettino GP,Lorenzi-Filho G, Kariralla RA,Deheinzelin D, Munoz C, Olieira R,Takagaki TY, Carlvahlo CRR. Effectof a protective ventilation strategyon mortality in acute respiratorydistress syndrome. N Engl JMed 1998; 338(6): 347-354.8) Lecomte F, Brander L, Jalde F, BeckJ, Qui H, Elie C, Slutsky AS, BrunetF, Sinderby C. Physiological responseto increasing levels of neurallyadjusted ventilatory assist (NAVA).Respir Phys & Neurobiology 2009;doi: 10.1016/j. resp 2009-02-015.9) Brander L, Leong Poi H,Beck J, Brunet F, Hutchison SJ,Slutsky AS, Sinderby C. Titrationand implementation of NeurallyAdjusted Ventilatory Assist incritically ill patients. Chest 2008;Doi 10.1378/chest.08-1747.10) Colombo D, Cammarota G,Bergamaschi V, De Lucia M, DellaCorte F, Navalesi P. Physiologicresponse to varying levels ofpressure support and neurallyadjusted ventilatory assist inpatients with acute respiratoryfailure. Intensive Care Med 2008;doi 10.1007/s00134-008-1208-3.11) Sinderby C, Beck J. NeurallyAdjusted Ventilatory Assist (NAVA): AnUpdate and Summary of Experiences.Neth J Crit Care 2007; 11(5): 243-252.12) Sinderby C, Navalesi P, BeckJ, Skrobik Y, Comtois N, FribergS, Gottfried SB. Lindstrom L.Neural control of mechanicalventilation in respiratory failure.Nat Med 1999; 5(12): 1433-1436.13) Sinderby C, Beck J, Spahija J,de Marche M, Lacroix J, NavalesiP, Slutsky AS. Inspiratory muscleunloading by neurally adjustedventilatory assist during maximalinspiratory efforts in healthy subjects.Chest 2007; 131(3): 711-717.14) Thille AW, Rodriquez P, CabelloB, Lellouche F, Brochard L. Patientventilatorasynchrony during assistedmechanical ventilation. IntensiveCare Med 2006; 32 (10): 1515-1522.

16 | Critical Care NewsSome of the many NAVA Nordic Summit meeting participantsNeurally Adjusted Ventilatory Assist:The first annual NAVA Nordic SummitMeetingTwenty-six intensive care clinicians from over eight hospitals in three countries participated in the firstNAVA Nordic Summit meeting in Solna, Sweden, in April. The purpose of the meeting was to providean opportunity to share NAVA clinical experiences and cases, and to build bridges for ideas for futurecooperation with NAVA, as presented by Claes Goderlöv of Maquet Nordic.There was a range of experience with NAVA, from ICU departments that are just starting out, and unitsthat have been using and gaining experience with NAVA as treatment methodology since the productbecame available in November, 2007. Experience in patient categories ranged from neonates to elderlypatients. Participants were also updated about ongoing NAVA clinical studies and future developments.The one day summit meeting is intended to be held for NAVA users on an annual basis.

Critical Care News | 17The twenty-six participants werewelcomed by Thomas Lindström, MDof Maquet Nordic, who gave a briefpresentation about the history ofthe SERVO ventilator, from the early1970’s to recent developments, suchas the MR and NAVA applicationsin the SERVO-i ventilator.The agenda for the meeting consistedof presentation of NAVA patient caseexperience from various Scandinavianhospitals. Dr Ninna Gullberg of theAstrid Lindgren Children’s Hospital inStockholm presented, from her unitwith experience of 20 patients. DrAmela Khorassani of Ryhov Hospitalin Jönköping, Sweden presented theexperience of NAVA in her adult patientICU from an 8 month perspective, and DrLisa Seest Nielsen of Kölding Hospital,Denmark, where NAVA has been recentlyimplemented, shared a few cases fromtheir 10 patient collective experiences.The meeting was moderated by SylviaGöthberg, MD, PhD, pediatric intensivecare physician from Queen SylviaHospital in Gothenburg, Sweden, andArne Lindy of Maquet Critical Care.Recent NAVA experience fromDenmark in adult patientsIntensive care physician Lisa Seest Nielsenfrom Kölding in Denmark, described herICU as an 8-10 bed medical unit for adultModerators Sylvia Göthberg, MD,PhD and Arne LindyICU physician Dr Lisa Seest Nielsen from Kölding, Denmarkpatients, who are often lightly sedated.NAVA had been implemented in theICU a few months prior to the meeting,and she described two patient casesof interest that they have observed.Case 1The first patient was a 78 year oldwoman, admitted for pneumococcalbasedpneumonia. The patient hadbeen in hospital for over 2.5 months,and NAVA was utilized to wean thispatient. Since the patient was ventilatedconventionally for 2.5 months, therewas a condition of hyperventilation anddiaphragmatic atrophy. Initial settingsincluded a NAVA level of 1.4 cm H 2 0/µv, with tidal volumes of 750-800 ml.The Edi peak value was about 20 µv.The NAVA level was adjusted down to0.4 cm H 2 0/µv to obtain tidal volumes of350-400 ml, and an Edi peak of 75-80 µv.The patient was also being treated withhemodyalisis as a complicated case withacidosis. The NAVA level was increasedto 1.5 cm H 2 0/µv with Edi max of 20-25µv and tidal volumes of 350-400 µv. DrNielsen said that the strategy was todecrease the NAVA level in incrementsof 0.2 cm H 2 0/µv, as the diaphragmaticmuscle regained strength. The strategyalso succeeded by maintaining avery low PEEP of about 4, in order totitrate in relation to the acidosis.Case 2The second patient case reported byDr Nielsen was a 55 year old womanwith difficult respiratory patterns, whohad been ventilated for a period of timewith Pressure Control and PressureSupport ventilation, with significanthyperventilation. The Edi catheter wasplaced, and the Edi signals and irregularrespiratory pattern were observed inswitching from controlled ventilationto Pressure Support. NAVA wasimplemented, and as the sedation levelsstarted to decrease, NAVA worked verywell and the patient was able to beextubated without any difficulties at all.Dr Nielsen commented: “The patientweaned herself with no difficulties onNAVA, it was us physicians at bedsidethat disturbed the order of the processby switching between controlled andsupportive modes, prior to NAVA.”

18 | Critical Care NewsExperience of NAVA at Ryhov Hospital,Jönköping, Sweden in 22 patientsThe Ryhov Hospital of Jönköping is aregional hospital with 7 intensive care beds.Dr Armela Khorassani has been workingwith NAVA since it was implemented inSeptember 2008. Together with ChiefICU Physician Peter Nordlund, she hascollected data from 22 NAVA patients,between the ages of 10 and 89 years.These patients have had diagnoses suchas pneumonia, pulmonary fibrosis, sepsis,peritonitis, diabetes, COPD and musclehypotrophy. She presented the preliminaryresults of the data collection so far:Total days in NAVA: 1-10Average days in NAVA: 4-7Total days of MV: 2-23Average days of MV: < 10 daysBenefits with NAVA:- Tracheotomy was avoidedin 5 patients.- Probable shorter hospitalizationin 7 patients.- Edi led to diagnosis in 1 patient.Difficulties with NAVA:- Asynchrony alarms in 6 patientsdue to earlier software versions, butalso deep sedation and high PEEP.- No or little Edi signals in 3 patients,who had sedation difficulties dueto cramping and anxiety, andrequired higher levels of sedation.- NAVA did not work in 2 patients,Dr Khorassani observed that inpatients with large hiatus herniait is difficult to place the Edicatheter and get signals.Complications due to NAVA:- No complications havebeen observed to date.Dr Khorassani went on to describetwo NAVA patient cases, one of theearly experiences and a more recentpatient case that had been treated.Case 1The first NAVA case was an 80 year oldwoman, with respiratory difficulties, anex-smoker who had fatigue and difficultyDr Armela Khorassani, of Ryhov Hospital in Jönköping, Swedento breathe in the past 6 months. Inthe two weeks prior to emergencyadmittance, she had increasingsymptoms of an upper airway infection.When admitted she had saturation of85%, respiratory rate of 33, pulse of110 with sounds of secretions whenauscultated. She was given oxygenby mask and antibiotics. However,she rapidly became worse, with anatypical pneumonia. A CT scan of herthorax showed findings of tree-in-budwhich were interpreted as an airwayinfection and bronchiolitis. The lung x-rayshowed different areas of infection.As she had more difficulty to breathe,she was intubated, and the staff believedshe would be difficult to ventilate,with a long period of mechanicalventilation. Her antibiotics werechanged and increased. NAVA wasimplemented directly. Initially the patientwas difficult to ventilate, followed bysteady improvement. Dr Khorassanipresented the following results:- NAVA for total of 7 days,of total of 8 days of MV- Initial Edi 11 µv, end Edi 24 µv.Initial PEEP 16, end PEEP 4.- Initial PIP 30, end PIP 11. InitialNAVA level 1.5 cm H 2 O/µv, endNAVA level 0.2 cm H 2 O/µv- FiO 2 initially 45%, end FiO 2 30%.Initial PaO 2 14, end PaO 2 9.96.- Initial PaO 2 /FiO 2 ratio was 32,end PaO 2 /FiO 2 ratio was 33.There were some difficulties withasynchrony alarms, with very high Edivalues on two occasions, bronchoscopyindicated stagnating secretion in the tube,which was switched to a larger tube.The final result was summarized by DrKhorassani as a diffuse pneumonia andpulmonary hypertension. The patientcould be extubated without need fortracheotomy. The Edi was monitoredafter extubation, and the patientneeded intermittent NIV for 2 days.

Critical Care News | 19Case 2The second NAVA patient case presentedby Dr Khorassani was a 89 year oldman, diabetic, with a recent historyof orthopedic surgery in the hip andpelvis after an accidental fall. He wasadmitted into the emergency roomwith a rapid onset of loss of strengthand motor function in his entire body,and a limited consciousness. He couldnot neurologically lift his legs. Upon CTexamination of the brain there was nofinding, however an X-ray of the neckrevealed a fracture through the C7 area.The patient was moved to theorthopedic clinic. An MR showed adegenerative tumor behind C1-C2 levelwhich compromised bone marrowand caused edema in the area. Thiswas judged to be the cause of therecent rapid onset of degradation.The patient was then transferred tothe neurosurgical unit for cervicalsurgery with fixation from C6-Th1. Postoperatively,the patient had worsenedneurologically with a complete tetraplegia.The patient was tracheotomized, afterunsuccessful attempts to extubate,no respiratory drive and completedependency upon mechanical ventilation.The patient was moved to the ICU forcontinued mechanical ventilation andto observe for signs of neurologicalrestitution. He was awake andcommunicating with miming andblinking upon admittance to the ICU.Initial ventilator settings were PressureControl, PEEP 10, PIP 29, RR 15, withno sedation. NAVA was attempted inthis patient as a means to determineif the diaphragm was functioning.NAVA was only used for 2 days,since, due to a weak diaphragmaticsignal and function, the ventilatorswitched back to back-up modes.Dr Khorassani presented the final resultas meddular damage with no phrenicactivity, and little accessory muscleactivity, the diagnosis was provided byNAVA and the Edi signal. The patientbecame vasoplegic and died. UtilizingNAVA and Edi in this case probablymeant that this patient had a shorterperiod of hospitalization and suffering,according to Dr Khorassani, sincereceiving the diagnosis by anothermeans, for example MR of the neck mayhave required more time on the unit.Dr Armela Khorassani and colleagues

20 | Critical Care NewsDr Ninna Gullberg, of the PICU of Astrid Lindgren Children’s Hospital, Stockholm, SwedenExperience of NAVA at AstridLindgren Children’s Hospital,Stockholm, SwedenDr Ninna Gullberg began her presentationby summarizing the experience withNAVA within her unit. NAVA wasimplemented in the autumn of 2008, andhas since been used in 15 to 20 patienttreatments. The case she presentedwas one of the first infants to be treatedwith NAVA during the autumn of 2008.Infant NAVA caseA six week old infant was transferredto the ICU, ventilated and sedated, andtreated with Sildenafil, Bosentan andIloprost inhalations. The baby was treatedwith Pressure Control ventilation withsettings PIP 25, PEEP 7, RR 50-60 andFiO 2 0.35-1.0. The baby was triggeringbut needed intermittent heavy sedationas the child did not tolerate to be awake.Since the child did not seem to betolerating the ventilator, he was switchedto NAVA and immediately seemed muchmore settled. For this particular infant,Dr Gullberg stated that NAVA offeredthe possibility to be awake and morestable, with less problems of “near deathepisodes”, but with higher pressures,high tidal volume and high Edi signals.The initial settings with NAVA were thesame volumes installed with Edi signals,a NAVA level of 0.8 cm H 2 0/µv, whilethe child was still under sedation. Asthe child awoke, pressure was limitedand with a low respiratory rate, theNAVA level was adjusted to 1.4 cmH 2 0/µv and the Edi signal decreasedbut the alarm limits were a limitation,due to an older version of NAVAsoftware. Despite the alarms, the childwas awake, seemed to be improvedand the blood gases looked good.As the child was improving it wasdecided to make an extubation trial,which resulted in immediate failure.There was high airway obstruction, anda tracheotomy was made, and CPRgiven in connection with bronchoscopy.Postoperatively the child was returnedto Pressure Control ventilation, althoughwith frequent recurring “episodes”.After switching back to NAVA, the childseemed more stable again. Causeand effect were discussed, a generalworsening situation perhaps due tosepsis, according to Dr Gullberg, witha vicious cycle of Pressure Controland episodes. The child seemed to domuch better when switched to NAVA,however with the older software versionalarms it became a bit of a departmentjoke; “The baby had a hard time to livewithout NAVA, but the staff had a hardtime to live with it!” said Dr Gullberg.The staff determined that moreinvestigation was needed to determinethe cause of the high pressures,the high Edi signals, if this was dueto the long period of ventilatorytreatment or diaphragmatic function.

Critical Care News | 21Screen values of infant treated with NAVA at Astrid Lindgren Children’s HospitalUpon a new failure to wean, anMRI angio was made and found noperfusion of the right lung. Thereafter,bronchoscopy indicated intermittentobstruction of the main lung bronchuswhich was compressed by the rightatrium. A V/Q scint confirmed thatthe right lung was better ventilatedwhile the left lung was being perfusedbut intermittently not ventilated.After these investigations, there wereextensive national and internationaldiscussions regarding possible treatmentfor this severe situation. Thorax surgeonsfrom the University Hospital of Lund, andspecialists from Stockholm and GreatOrmond Street Hospital in London wereconsulted. It was determined that therewould be no chance to win any significanttime by any means, and that no treatmentwas available for this case. Palliative carewas initiated until the infant passed away.Dr Gullberg summarized the experienceof NAVA in this patient situation:- NAVA provided time toexplore options- NAVA provided comfort and:• A relationship between theinfant and the parents• Some joy in a short life; betweencrises, NAVA allowed the infant tobe awake and to laughand smile when trying mangopuree for the first time.• Knowledge for the futureDr Gullberg ended her presentationby saying that this patient had beenon NAVA for an extended period oftime with no symptom of thoracicinvolvement, and the limitation of NAVAwas not the NAVA level but the alarmsettings in the older software versions.A final presentation was madeshowing milestones in developmentsince the NAVA application forinvasive use was released for sale inNovember 2007. A number of clinicalstudies were summarized that arecurrently ongoing with NAVA:- Patient-ventilator synchrony- Comparing NAVA andPressure Support- Sleep studies- Sedation studies- Studies of NAVA and hemodynamics- Local and regional NAVA studies that arecurrently generating scientific abstracts.Educational resources currently availablefor NAVA were reviewed, consisting of ane-learning package, a study guide, tutorials,a pocket guide, and NAVA interviews,lectures and patient case reports locatedin www.criticalcarenews.com.

22 | Critical Care NewsDr Rory Mackenzie, Clinical Director and Consultant Anaesthetist; Dr Sanjeev Chohan, Consultant Anaesthetist; Dr David Clough, ConsultantAnaesthetist, and Dr Jim Ruddy, Consultant Anaesthetist/Intensivist have all been gaining experience with NAVAImplementing NAVA and Edi monitoringas lung protective elements in a regionalhospital ICUMonklands Hospital on the outskirts of Glasgow in Lanarkshire, Scotland is a district general hospitalwith 521 inpatient beds. Monklands Hospital provides the Larnarkshire district patients with renalcare, an emergency department as well as inpatient services for ENT, dermatology and communicabledisease.This means that the six bed intensive care department of Monklands Hospital treats a wide variety ofbetween 360 and 380 medical and surgical ICU patients a year. These ICU patient challenges are metby five intensive care consultants and 26 critical care nurses, who are implementing lung protectiveventilatory strategies on a routine basis. The ICU staff members of Monklands Hospital recentlyimplemented Neurally Adjusted Ventilatory Assist – NAVA as well as Edi monitoring in their unit. Theybecame positive to this new methodology after experiencing it in a worst-case scenario, with a patientthat had been on mechanical ventilation for 62 days. Critical Care News spoke with Dr Jim Ruddy tohear of their experiences and observations.

Critical Care News | 23have treated about 10 patients withNAVA. (Editor Note: this NAVA patientcase report will be published and locatedon www.criticalcarenews.com).How routinely is NAVAused in the ICU?We have NAVA at every bedside but weonly have 2 Edi modules, which is enoughat a unit of this size of 6 ICU beds. Thatis enough for the potential use of NAVAon a weekly basis, with the capabilityavailable for all ventilators. At the currenttime, we have experienced an averageof 1 or 2 patients a month on NAVA.Are there specific staff membersusing NAVA, or has all the generalICU staff received training?Dr Jim Ruddy at patient bedsideCan you describe the primaryfactors and process leading tothe decision to investigate andimplement NAVA in this ICU?Dr Jim Ruddy: It was the fact thatwe were changing our ventilatorfleet, but also the fact that many ofus were curious about NAVA, and arewondering where its niche is goingto be. Quite a few of us here have aninterest in lung recruitment maneuversand ventilator strategies, it seemedthat this package of the ventilator withoptions for lung recruitment and NAVAgave us the opportunity to combinerecruitment with weaning opportunitiesas a lung protective package.When did you have your firstpatient experience with NAVA?Our first case was the patient case thatwe had in the beginning of the year,about 5 months ago, which turned outto be a worst case scenario for a 25 yearold patient with severe pneumonia, whodeveloped polyneuropathy, sepsis, ARDS,renal failure and so many complicationsthat we were constantly afraid of losingher. She was in the ICU for 100 days,and it was one of those cases whereeverything went from bad to worse.We were able to wean her off over amonth of HFO with the help of NAVA.It worked an absolute treat, and madebelievers of us all here. Since then weTraining is an ongoing process, and weconducted initial training for key users,and we have been educating the rest ofthe staff in succession ever since. Thetrainees that are interested in intensivecare are quite keen on learning NAVA;they see it as a useful knowledge baseto mention when they go on to train atother intensive care units and hospitals.That is spreading the news in a good wayas well, since the trainees are seeingwhat could be useful in monitoring Edi; isit high or low, or affected by sedation, andin conventional modes as well as NAVA.It is quite nice that the interest from thetrainees can flow from the bottom upwhen they go to other institutions. Weconducted a study day as well, where weoffered NAVA training sessions to staff inall the intensive care units in Lanarkshire.All of the critical care nurses got insightinto NAVA and why we are using it here.Who within the ICU is responsiblefor insertion of the Edi catheterand who is responsible forplacement verification anduse of the Edi catheter?We consultants change the Edi catheter,place and verify it, unless there is a traineeon the unit that would like to learn. This isabout the easiest part of the procedure, toplace the Edi catheter and verify placementby means of the esophageal ECG signals.

24 | Critical Care NewsPpeak was only about 2 µv which againcaused us to believe that her breathingcenter was impaired. We have also hadthe usual type of patients where wewanted to see if NAVA could improvetheir ventilator dyssynchrony and Edimonitoring gives us the possibility to seethe diaphragm activity and synchronyin conventional modes and in NAVA.What is the average time on NAVA?From our experience in hard to weanpatients so far, it is difficult to say. Iwould say that we will trial it in thecategory of difficult to wean patientsin 2 or 3 days to see if it will make adifference. If it is making a difference,we will carry on until we must changethe Edi catheter. We then switch thembriefly back to the equivalent PressureSupport mode, to see how their NAVAvalues are corresponding with that.Does the team do a follow-upor review of the progress ofeach NAVA patient case?Dr Jim RuddyIs monitoring of the Edi signalused in conventional ventilatorymodes or in stand-by?In terms of monitoring Edi in stand-by onpatients that have been weaned but notyet extubated, we have not tried this yet,but it may well be if the work of breathingcorrelates with the Edi peak, we canconclude that the patient is getting tiredand may need to go back on the ventilator.With regard to monitoring of Edi signalin conventional modes, in the patientpresented in our case report, this girl hada severe critical polyneuropathy, probablythe worse I have seen, she couldn’t lifther hands up. Even on the HFO, shewould make respiratory motions but shewas so weak she would not interferewith the oscillation. In weaning her, wethought that since she was making thesemovements or attempts that it might behelpful to measure her Edi, which wouldgive us a chance to gauge her level ofsupport so much more closely than anyother conventional means of monitoring.While she was on the oscillator, wenoted that she was making attempts tobreathe, and her Edi was in the 70-75-78µv range. She clearly wanted to breathe,but did not have the diaphragmaticmuscle power to do that. From thisfirst patient, it has been actually quiteuseful to think of Edi monitoring in thisperspective, of diaphragmatic monitoring,even in conventional modes. We also hada patient who we suspected might havea primary neurological insult, such as abrain stem injury, and we placed an Edicatheter to see if she actually had anyactivity from her phrenic nerve, or wasmaking respiratory effort. Interestingly,her activity was minimal; her EdiCertainly, we are fortunate to have a tightknit consultant group. We discuss theindividual management of all patientshere on a regular basis. On top of thiswe consult each other in regard to NAVA.If there are consultants with less NAVAexperience, but they see a patient thatthey think might benefit, they usuallydiscuss together with other colleaguesthat have more experience, prior toplacing the Edi catheter. There is a lotof positive feedback in general on theunit. We are quite unified in all things wedo, which is great for a new therapy, itmeans that the enthusiasm is there allthe time, we are quite lucky that way.What in your opinion are the specificelements or factors needed in order toimplement NAVA on a routine basis?What is most important to thinkabout when implementing NAVA?You’ve got to be enthusiastic about it.I think it is helpful to be someone whois interested in the concept, and what itmay potentially provide, not necessarilywhat it is giving at the present. I think

Critical Care News | 25people still are not clear on that, in ourdepartment we are really interested tosee how NAVA will help us in the areaof sedation and sedation-related issues.We think that in giving sedation breaksand spontaneous breathing trials, thatmaybe the Edi will help us to gauge thedepth of sedation used in the unit. AndEdi monitoring is fairly non-invasive; anasogastric tube usually goes downanyway, so we believe that the additionalinformation provided by Edi will hopefullydecrease ventilator time, decrease lengthof stay, and decrease costs, which canonly be a good thing. We do not know yethow NAVA or Edi monitoring will deliveron these variables, but I think one musthave the enthusiasm to realize this is anew novel way of getting to the heart ofwhat is controlling the respiratory cycle.I think, to improve patient synchrony andperhaps avoid sedation or deep sedationto do that, can only be positive. If youbelieve in the concept, then that is allyou have to do, and be keen to learnabout it and teach others as you go.Which types of patient categories areyou most interested in gaining moreNAVA experience with, and why?Acute brain injury, prolonged weaning,we used it in a high spinal cord injury, butthat was at C5 and it gave a good signalwithout problems. I don’t think we arethinking about new patient categoriesfor NAVA, rather expanding the use tolook at things like sedation levels. Weare keen to use Edi monitoring to seewhat happens in patients that may havesuffered brain stem infarct or edema.We did have one case of a patient whereI wanted to know what the respiratorycenter was doing. Edi monitoring wasvaluable to help us determine that thiscase was brain stem dead. We haveused NAVA in the hard to wean patientcategory, however Edi monitoringprovides opportunities in many differentareas. The other monitoring opportunitieswe are interested in are depth ofsedation, and sedation scoring. Titratingsedation by protocol with help of Edimonitoring and NAVA can have long termbenefits, and avoiding delirium in patientscan have long term benefits. Maybe theEdi might reflect another way of assistingthe patient level of sedation, or avoidingdiaphragm disuse atrophy, which may berelated to sedation levels.We have a busy unit, with a lot ofventilated cases, and we have probablythe worst deprivation in Europe in thisregion, our co-morbidities are enormous;alcohol consumption, smoking, druguse, unemployment, poor housing,and poor diet. In the east end ofGlasgow and Larnarkshire, we do havea population with a high rate of ischemicheart disease; male life expectancy isless than other regions in Europe. IfNAVA and Edi monitoring can help usto improve these patient outcomes inany way in intensive care, it is good.Do you think that this ICU will beexpanding the use of NAVA in future?Right now, we see the opportunityfor NAVA in the hard to wean patientcategory. For complex cases, theseare the NAVA candidates we see: longstayers, difficulty in weaning, medicalpatients with a number of differentco-morbidities, which is where we findbenefit at present. NAVA provides uswith the next step for the patient to getthem off the conventional ventilator.In terms of the oscillated patient, wethink that NAVA was elementary to gether off the HFO and into weaning.Dr Sanjeev Chohan, Consultant Anaesthetist, and Unit Sister Isabel PatersonBiographiesDr James Patrick Ruddy attendeduniversity at Edinburgh MedicalSchool from 1986-1991, withdistinctions in Obstetrics andGynaecology and obtained thedegree of M.B.Ch.B in 1991. HIspost-graduate degrees includeFRCA in 2001, ALS, ATLS, andPALS: Provider in 2005. Dr Ruddywas awarded the Scottish IntensiveCaer Society/West of ScotlandIntensive Care Society TravellingFellowship in 2005. He obtaineddual C.C.T. in Intensive CareMedicine/Anaesthetics in 2006.Dr Jim Ruddy is currently Secretaryof the West of Scotland IntensiveCare Society and Lead AuditConsultant for Intensive CareMedicine Monklands Hospitaltogether with the lead for Research.He is also Clinical Lead for OrganTransplantation in Lanarkshire. DrRuddy is also principle investigatorfor the “TRAPPHIC” study(Prophylactic Aciclovir in ICU) andhas also recently been appointedSenior Clinical Lecturer in IntensiveCare Medicine and Anaethesiafrom the University of Glasgow.Dr Ruddy is currently employed asConsultant in Intensive Care Medicineand Anaesthesia at MonklandsHospital, Airdrie, Scotland.

26 | Critical Care NewsWilliam Twaddle, RRT and Jagadeeshan Sunderram, MD at bedside with MICU patientInterdisciplinary implementation ofNeurally Adjusted Ventilatory Assist –Robert Wood Johnson University HospitalThe award-winning Robert Wood Johnson University Hospital and its associated Bristol-Myers SquibbChildren’s Hospital have been at the forefront in implementing new innovations in patient care. Theyhave been ranked among the top 50 in Cardiac and Respiratory Services in the US by US News andWorld Report for the past two years.The institution was among the very first in the United States to introduce Neurally Adjusted VentilatoryAssist, or NAVA to the Medical ICU, Surgical ICU, Cardiac ICU as well as the Pediatric ICU and NeonatalICU. Critical Care News spoke with members of the interdisciplinary teams to hear about theirexperiences with NAVA, and plans for the future.

Critical Care News | 27Gaining experience withNAVA in the neuro and cardiacunits of the surgical ICUKumar DeZoysa, who is surgical clinicalcare coordinator, has been workingwithin Robert Wood Johnson UniversityHospital for over 20 years, and hasseen implementation of a number ofventilatory modes during that timespan. He describes his experiences andimpressions: “When NAVA becameavailable to the US, we were one of 4centers to begin to implement it. I amvery excited about NAVA because I thinkit is the future within respiratory care.”“Our first case was a cardiac surgerypatient, and we learned a lot fromhim. The patient was paralyzed andsedated, and it was tumultuous, aCABG surgery. We did not get goodEdi signals to start out with, butit was a learning experience.”“Each NAVA patient was a memorableexperience, but probably the mostmemorable experience was a patientwho presented with chest pain in theemergency room. He was transferredto the floor, and the patient codedwhile being transferred. They intubatedhim and brought him down and for thenext two weeks he was considered afailure to wean patient. We had twomajor disciplines involved in the case,pulmonary and cardiology services. Eachconflicted in the diagnosis. Pulmonaryinsisted that it was cardiac etiology thatkept the patient from being weaned;cardiology insisted it was a pulmonaryissue. The attending intensivist who wasa pulmonologist requested that an Edicatheter be placed so we could monitorthe Edi during the weaning process.The patient did not demonstrate anyincreasing Edi, which the physicianimplied was correlated to no increaseof work of breathing, so cardiacinsistence that this failure to weanwas due to pulmonary etiology wasruled out. The Edi provided informationthat we would not have otherwise.”Kumar DeZoysa sees a role for NAVAas well as Edi monitoring in NAVA andin conventional ventilation modes infuture: “I think there are a few thingsthat will be developing in the future:Kumar DeZoysa, RRT, is Surgical Clinical Care Coordinator at Robert Wood Johnsonamounts of tidal volume and ratesas prescribed by the Edi signals willbecome more acceptable, as well as theamount of PEEP that will be prescribedby the patient Edi signals. Once that isestablished, the future is set. Hospitalsgenerally use inadequate PEEP, andonce we start using optimal PEEP,patients will recover faster, we will seepatients leaving the unit and the hospitalfaster, all of those things will fall intoplace. Right now, everyone prescribesa standard PEEP level, which may notbe right for every patient. In general,we are not giving the PEEP required, sopatients struggle with a lot of tensionon the backbone and a lot of work ofbreathing, with difficulties to wean.”Kumar DeZoysa regards every patientadmitted to the ICU as a potentialcandidate for Edi monitoring andNAVA. He also regards NAVA as agenerational shift in ventilation therapy:“The analogy we draw is the Swan-Ganz catheter to the heart is what theEdi catheter is to the lung. What didwe have to monitor the lung prior tothis? We only had x-rays, blood gases,and respiratory rates. I do encourageanyone in respiratory care to learn aboutNAVA and use it when possible.”

28 | Critical Care NewsMedical Director Jagadeeshan Sunderram, MD, shared his experiences with NAVA in MICU and CCU patientsNAVA in the MICU and theCCU at Robert Wood JohnsonUniversity HospitalDr Jagadeeshan Sunderram is MedicalDirector and head of the MedicalIntensive Care Unit with 16 beds andoverflow Critical Care Unit with 15beds since 2002. He has also been amember of the faculty of the RobertWood Johnson Medical School since1999. When he first heard about thepossibility to implement NAVA withinthe unit, it was not a totally foreignconcept to him. “My research actuallywas implanting diaphragmatic EMGelectrodes and measuring neural outputdirectly in animal models, so obviouslythat piqued my interest in NAVA.”“We saw our first NAVA patient about ayear ago, which was a patient overflowfrom the MICU to CCU, a case of failureto wean. The question was if there was acardiac element to his failure to wean, orwas it a problem with strength? I thoughthe would be a good candidate for NAVA,which would assist us to differentiatethe two. That was our first start.”“It was interesting with the Edi catheterdetecting the diaphragmatic effort, andas we monitored the Edi we were ableto see a cardiac issue that led to hisinability to get off the ventilator, andonce that was fixed, he was weaned.NAVA helped us to distinguish if it wasan issue of heart failure or strength.”Dr Sunderram sees a role for NAVAparticularly in the failure to weancategory, which he estimates to beabout 10% of patients with persistentrespiratory failure. “The other 90 percentof our patients are extubated within 2days of their intubation, on average. It isthe ones that do not wean successfullythat we suspect may have an issue ofventilator dyssnchrony, impaired drive orstrength, or a cardiac versus lung relatedissue, where NAVA is able to help usand we use NAVA in these situations,”explains Dr Sunderram. He describesanother NAVA patient case:”We havehad a situation in another patient wherehe was transferred from another hospitaldue to failure to wean, with repeatedepisodes of hypercapnia and respiratory

Critical Care News | 29failure and we did not know the cause ofthat. We decided to place an Edi catheterso we could better understand whatwas going on and we could see whatwas happening with his diaphragmaticstatus and ventilator synchrony. He hadmultiple infiltrates, and heart issues,among other complications. When weplaced the Edi catheter we could seethat he was in total synchrony with theventilator, his diaphragm was workingfine, and within a couple of days we wereable to extubate him without a problem.NAVA really gave us an insight into hisproblem, and his hypercapnic respiratoryfailure turned out to be more of an issueof cardiac loading that needed fixing.”Dr Sunderram states that the educationaleffort for NAVA and Edi monitoring isan ongoing process of experience bydoing. “Every patient on NAVA givesus a learning opportunity, and we worktogether and review Edi monitoringduring rounds.” He also states thatin the difficult to wean category ofpatients, such as COPD, patients withneuromuscular weakness, patientswith issues of drive or stroke and/or cardiac problems are particularlyinteresting in regard to NAVA: “Thoseare the patients that if they stay onthe ventilator for a longer period oftime, we start to have a difficult timediscerning the physiology behind theirfailure to get off the ventilator. Themore ventilator support ICU patientsare given, the greater potential fordiaphragmatic muscle atrophy. I thinkNAVA is a very valuable tool for us tounderstand their diaphragmatic effort,issues of drive and strength versusload, and to separate them and to treatthem accordingly. I see a clear benefitfor NAVA in this group of patients.”William Twaddle, who is clinicalcoordinator for the MICU, and CCU atRobert Wood Johnson University Hospitalhas been working in this capacity for thepast few years, and has been working atthe hospital for more than 20 years as arespiratory care staff member. He is veryexcited about NAVA, and clearly recallshis first NAVA experiences in the MICU:“Our first patient was a tough patient. Wewanted to use it on a COPD patient tostart out with, and we had a physicianwho said to try it on a bad asthmatic.William Twaddle, RRT, is MICU and CCU Clinical Coordinator at Robert Wood JohnsonOur experience with that was actuallyvery good, since we saw all kinds ofdifferent and new things. We saw by theEdi signal that the patient was still instatus astmaticus, and was not ready forweaning. The Edi catheter was in for awhile and we monitored and saw whenthe patient was ready to wean. It wasa very valuable learning experience forus. That maybe should have been ourfifth patient, but was our first which wasgood since it was more challenging andwe learned so much in the process.”William Twaddle says that Edi monitoringis also valuable in conventional ventilationmodes: “If we can get them to NAVA,we want to try, since we want themto be spontaneously breathing. If Ihave to work with them, depending onthe patient response, we look at theEdi signal to take workload off, to putworkload on, we look at Edi to see if theyare tolerating and when they are failing.”He describes the Edi catheter insertionand placement procedure: “When itcomes to Edi catheter insertion, it isa nursing process here, per hospitalpolicy. The nurses verify placementas a nasogastric tube, and we verifyplacement as an Edi catheter with thepreview screen and the ECG readings,and we do tend to reposition slightlyif needed for the Edi signals.“

30 | Critical Care News“I definitely think that we will see thecontinued use of NAVA as well as Edimonitoring of NAVA and conventionalmodes. Dr Mehta is interested in utilizingNAVA in looking at apnea of prematurity,where he sees a potential value.”Increasing future use of NAVAand Edi monitoring in the PICUThe first patient experience with NAVAin the PICU of the Bristol-Myers SquibbChildren’s Hospital of Robert WoodJohnson University Hospital was a 4month old infant, where NAVA ventilationand Edi monitoring were utilized on thechild for one week. Jacqueline Williams-Phillips, MD, Director of Pediatric CriticalCare Medicine describes the case: “Thischild presented with respiratory failurea number of times of unclear etiology.We were unsure if it was a muscularskeletalproblem or a neurologicalproblem. Genetic issues could come intoplay. We thought we would try NAVA tosee how his brain stem and diaphragmrelationship was working, before moreinvasive measures such as musclebiopsies or diaphragmatic biopsies.”Dana Saporito, RRT is Clinical Coordinator of the NICU at Bristol-Myers Squibb Children’sHospital of Robert Wood Johnson University HospitalExperience transitioning from jetventilation to NAVA in the NICUNeonatal Intensive Care Unit ClinicalCoordinator Dana Saporito hasseen NAVA in two infants withbronchopulmonary dysplasia patients,which were patients of attendingneonatal physician Dr Mehta. Shedescribes these cases: “Both of thepatients were difficult to wean, but onewas more difficult than the other towean from the jet ventilator. One babywho we thought would be a candidatewas born on December 24, and he hada week of conventional ventilation, aftertwo weeks we tried to wean him butat every weaning attempt we saw hisCO 2 rise into the 70s and 80s. Dr Mehtahad read about NAVA and wanted to tryit. After we started NAVA in this baby,the very first blood gas we got backwas phenomenal. The improvementwas pretty instantaneous. The babywas on NAVA for five days and he wasdoing wonderfully. We were planningto extubate him but he had a seizure.”“Because of what we saw in this patient,we decided to try NAVA on anotherdifficult to wean patient that was onconventional ventilation on a babyventilator by another manufacturer. Weinserted and placed the Edi catheter andmonitored the baby on the baby ventilatorby another manufacturer, but he seemedvery out of synch. We monitored theasynchrony by means of Edi signal for24 hours and switched him over to theSERVO ventilator and NAVA after that. Hewas on NAVA on the SERVO ventilatorfor 24 hours and we extubated him withno difficulties. He had failed two priorextubations on the baby ventilator.”Dana Saporito sees a continued role forNAVA and Edi monitoring of both NAVAand conventional modes in the NICU:“He continued on NAVA for some time,and Edi monitoring gave us a lot ofvaluable information in terms of neuralinput to his respiratory function, and wecould avoid painful muscular biopsiesand nerve conduction velocities andtook that diagnostic arm out of theprocess. He did go on for further testsat another institution after he left us.”Dr Williams-Phillips is excited aboutsome opportunities she sees with NAVAand Edi monitoring in future. “I amvery excited about a couple of ideas Ihave. Within the evolution of pediatriccritical care, we have all experienced acohort of patients who develop chronicrespiratory failure. There is a time framein these patients when tracheostomy isneeded, but we cannot predict reliablywhen that will occur. It may be dueto genetic disorders, neuromusculardisorders, and there will be a time whenwe must inform the parents that theirbaby or child is ready for tracheostomy.We do not have objective data aboutwhen that time is. What we do now isevaluate after the first respiratory failureevent, and see how frequently it may

Critical Care News | 31Jacqueline Williams-Phillips, MD, Director of Pediatric Critical Care Medicine, is excitedabout many potential opportunities with NAVAGerald Schlette, Director of Respiratoryand Pulmonary Services, sees thecapabilities of utilizing Edi monitoring,in NAVA and conventional modesrecur, every month or a few times a year.Sometimes these patients do betterwith tracheostomy later on with betterquality of life. Many patients have parentsthat then tell us, ”We wish this wouldhave been done earlier” but we do nothave any data to help us know whenthe optimal time for tracheostomy is.We know that once we do tracheostomythat it decreases hospitalization in thispatient category. My thought is whenthese children come in with respiratoryfailure, NAVA and the Edi catheter canprovide us with information about thestatus of the diaphragm in relation to therespiratory failure, and other information.NAVA would be a useful tool to predictif tracheostomy should be initiated inpatients with chronic respiratory failuredue to neuromuscular diseases and otherdiseases. It would also be useful to lookat the condition of the diaphragm posttracheostomy, if nighttime ventilationis needed in some circumstances.”“The second idea I have is that wehave the largest pediatric rehabilitationhospital in the country right next tous, and we often send children fromour PICU to them for rehabilitationfor better outcomes in neurologicalrecovery after brain injury. I think thatNAVA and Edi can provide valuableinformation in these patients to helpdetermine when to wean them and bringthem to the next level, as a means oftransitioning the patient off the vent,to improve the rehabilitation potential,and bring them home more quickly.”Summarizing experiences with NAVAand Edi monitoring to date at RobertWood Johnson University HospitalThe Respiratory Care Department atRobert Wood Johnson University Hospitalhas grown in recent years, from 45to a total of 56 registered respiratorytherapists on staff, according to GeraldSchlette, Director of Respiratoryand Pulmonary Services. He states:Pretty much all respiratory therapystaff members working in ICUs havebeen trained in the use of NAVA atthis point and I feel that support fromthe physicians has been strong.”“The capabilities of utilizing the Edimonitoring gave us much more thanwe expected, the diaphragmaticcondition is revealed to us. This wasan eye-opener for us, although wehad expected this was to be the case,this is the first time we had our ownevidence. Seeing is believing.”As Robert Wood Johnson is one of thefirst university hospitals in the US to startto use NAVA, as a teaching institution,there is motivation to include trainingand education about NAVA for futureclinicians. Gerald Schlette explains:“Training physicians is an ongoing

32 | Critical Care Newsprocess, and every July 1st we havean onslaught of new physicians. Wehave a course we teach for residentsin surgical and medical. We will beincluding NAVA in these courses, soafter a four year period everybodywill have had an in-service and therewill be a continuum from now on.”Derikito Servillano is Critical CareCoordinator within Respiratory Care atRobert Wood Johnson. He has beenworking for 14 years in respiratorytherapy and is responsible forcoordinating all other coordinators inMICU, SICU, PICU, and NICU as well asthe educational staff members. In thiscapacity, Derikito Servillano has had anopportunity to observe almost everypatient that has been treated with NAVAat the institution. He recalls his first NAVApatient experience: “The first patient Iremember very well, my first impressionwas letting go – it is very important to letgo but difficult to transition from absolutecontrol to no control. It was an asthmaticpatient, that was difficult but we tookthe opportunity since the physicianrequested for NAVA to be used. Welearned many things from that patient.I remember revisiting my physiologybook to relearn how the diaphragmaticand respiratory muscles work. Thatfirst patient gave us a huge educationaladvantage of what the Edi signal reallymeasures, and the learning curve wasso high that I vividly remember it.”“After seeing it for the first time,it was really a validation that whatthey were saying about NAVA wastrue. One thing that helped us wasthe monitoring capability of the Edisignal. It is easier to convince thephysicians that it is a good tool as itshows better synchrony than any othermeans we currently have available.”In his role as Critical Care Coordinator,Derikito Servillano also had to coordinatethe educational effort to prepare forimplementation of NAVA and Edimonitoring. He describes this process:“We had a core group of people tryingto learn as quickly as we could beforestarting. When we had one patient wecould coordinate all of the staff andnurses to observe and understand theapplication, so that they would have abuy in to what we were doing. The CICUDerikito Servillano is Critical Care Coordinator for Respiratory Care, and has observedalmost every patient treated with NAVA at Robert Wood Johnsonin the open recovery area started outwith the Edi signals as a monitoring tool.”From there we went on to implementNAVA as a mode of ventilation and Edimonitoring in the MICU, CCU and in theNICU and PICU. I recall a particularlyamazing experience in the NICU withNAVA in two patients. This experienceshowed me that these kids can be offsedation and they respond right away.”“In the adult arena, we continue tocollect experience with NAVA and Edimonitoring in the hard or difficult towean patients. We try NAVA and buildconfidence that the patient is strongenough, and so far we have not seen anyreintubation or reinstitution of mechanicalventilation with any of our NAVA patientsyet. In this respect, we need more timewith NAVA. I think maybe we need to goto NAVA earlier in the process of hard towean patients, and evaluate from there.”Derikito Servillano says that thephysicians have been accepting ofNAVA as a mode of ventilation, and Edimonitoring as a new vital sign in the ICU:“Yes, actually they are the driving force. Iwould say about 50% of our patients sofar have been physician driven, and therest have been on our recommendation.To me, the monitoring tool is a futurevalue for us, especially as an educationalinstitution it is important to identify andtell where dyssynchrony is on any mode.”

Critical Care News | 33Doug Campbell, Assistant VicePresident of Operations at RobertWood Johnson leaves a final summaryof the implementation of NAVA at RobertWood Johnson University Hospital:“The introduction of NAVA has been ina structured manner, through meansof input and feedback from key staffmembers, which provides a solidbase for the next level of experience.It is important that there is a forumfor communication between usergroups from different hospitals usingNAVA to sharing the experiences aseveryone goes forward with quantumleaps in technology. NAVA is cuttingedge and we want to make surethat we are on the forefront of thatprocess, in order to be competitive.”Derikito Servillano, with Doug Campbell, Assistant Vice President of Operations at RobertWood Johnson, has been supportive of the implementation of NAVA at Robert WoodJohnson University HospitalReferences1) Breatnach C, Conlon NP, Stack M,Healy M, O´Hare BP. A prospectivecrossover comparison of neurallyadjusted ventilatory assist andpressure-support ventilation in apediatric and neonatal intensivecare population. Pediatr Crit CareMed 2009; Jul 9 (Epub aheadof print PMID 19593246).2) Bengtsson JA, Edberg KE. Neurallyadjusted ventilatory assist in children:An observational study. PediatrCrit Care Med 2009; Jul 9 (Epubahead of print PMID 19593241).3) Zhu LM, Shi ZY, Ji G, Xu ZM,Zheng JH, Zhang HB, Xu ZW,Liu JF. Application of neurallyadjusted ventilatory assist ininfants who underwent cardiacsurgery for congenital heartdisease. Zhongguo Dan Dai Er KeZa Zhi 2009 Jun; 11(6): 433-436.4) Lecomte F, Brander L, Jalde F,Beck J, Qui H, Elie C, Slutsky AS,Brunet F, Sinderby C. Physiologicalresponse to increasing levels ofneurally adjusted ventilatory assist(NAVA). Respir Physiol Neurobiol2009; Apr 30; 166(2): 117-124.5) Beck J, Reilly M, Grasselli G,Mirabella L, Slutsky AS, DunnMS, Sinderby C. Patient-ventilatorInteraction during Neurally AdjustedVentilatory Assist in Very LowBirth Weight Infants. Pediatr Res2009; Jun; 65(6): 663-668.6) Brander L, Leong-Poi H, BeckJ, Brunet F, Hutchison SJ, SlutskyAS, Sinderby C. Titration andimplementation of Neurally AdjustedVentilatory Assist in critically illpatients. Chest 2008, Nov 18,2008, DOI 10.1378/chest.08-1747.7) Colombo D, Cammarota G,Bergamaschi V, De Lucia M, DellaCorte F, Navalesi P. Physiologicresponse to varying levels ofpressure support and neurallyadjusted ventilatory assist inpatients with acute respiratoryfailure. Intensive Care Med 2008;DOI 10.1007/s00134-008-1208-3.8) Laghi F. NAVA: brain overmachine? Intensive Care Med 2008;DOI 10.1007/s00134-008-1215-4.9) Sinderby C, Beck J. ProportionalAssist Ventilation and NeurallyAdjusted Ventilatory Assist-Better Approaches to PatientVentilator Synchrony? Clin ChestMed 2008: 29(2); 329-342.10) Sinderby C, Beck J. NeurallyAdjusted Ventilatory Assist(NAVA): An Update and Summaryof Experiences. Neth J CritCare 2007:11(5): 243-252.11) Emeriaud G, Beck J, Tucci M,Lacroix J, Sinderby C. Diaphragmelectrical activity during expirationin mechanically ventilated infants.Pediatr Res 2006; 59(5): 705-710.12) Navalesi P, Costa R. New modesof mechanical ventilation: proportionalassist ventilation, neurally adjustedventilatory assist, and fractalventilation. Curr Opin CritCare 2003; 9(1): 51-58.13) Sinderby C, Spahija, J, Beck J,Kaminski D, Yan S. Comtois N,Sliwinski P. Diaphragm activationduring exercise in chronic obstructivepulmonary disease. Am J Respir CritCare Med 2001; 163(7): 1637-1641.14) Sinderby C, Navalesi P, BeckJ, Skrobik Y, Comtois N, FribergS, Gottfried SB, Lindstrom L.Neural control of mechanicalventilation in respiratory failure.Nat Med 1999; 5(12): 1433-1436.

34 | Critical Care NewsReturn transfer of a 12 year old patient from the MRI to the PICU at Dartmouth-HitchcockImplementation of a seamless solutionfor bedside quality ventilation therapy incritical care patient transports and MRThe internationally renowned Dartmouth-Hitchcock Medical Center in New Hampshire in the UnitedStates is an academic medical center that has venerable roots stemming from Dartmouth MedicalSchool, which was the fourth medical school founded in the United States in 1797.The current state-of-the-art medical center facility was opened in 1991 as a 429 bed regional referraland teaching facility, including a trauma center and pediatric hospital. With 85 critical care patientsthroughout the facility, the Respiratory Care department faced challenges for in-hospital patienttransports, including the MR environment – how to provide a solution for critical care patient transportswithout compromising ventilation therapy?Critical Care News spoke with Scott Slogic, RRT, RCP, Director of Life Support, and Clinical EducatorMatthew McNally, RRT to hear of the solutions to these challenges.

Critical Care News | 35The fifty registered respiratory caretherapists on staff at the Dartmouth-Hitchcock Medical center face dailychallenges in caring for critical carepatients in the adult medical CCU,surgical and trauma units, as well as apediatric intensive care unit and a 30 bedlevel III intensive care nursery. The facilityalso offers a coronary referral center andCICU where patients arrive from over28 hospitals within the region. With anaverage of 82 critical care patients fromall categories – infant, pediatric and adult,the Respiratory Care Department werelooking for an opportunity to standardizein 2002, without compromising quality inventilation for their critical care patients.A concept for standardizingventilation therapyDirector of Life Support, ScottSlogic, RRT, RCP has been head ofthe Respiratory Care Department atDartmouth Hitchcock for over twelveyears. He describes the resourcesand activities within the RespiratoryCare Department: “We have about50 registered therapists, and we runtypically 8-9 staff members per 12 hourshift. We have a clinical educator andan equipment manager, and transporttherapists also, that are flight qualifiedthat go on specific types of transports.We have two helicopters, and twoambulances, we do about 400 externaltransports per year. The majority of theseare intra-hospital and planned transports,rather than trauma and emergency,although that may occur periodically.More frequently it is a matter of ahospital contacting us with a sick childthat is referred over to our institution.”“I have been working in this capacityin Respiratory Care for 12 years. LifeSafety is a new concept, that of avirtual department that functions toimprove patient safety throughout theorganization. We have a Life-SafetyNursing Consult service, and these RNsare also part of the Rapid ResponseTeam, termed HERT (Hitchcock EarlyResponse Team). The nurses are partof the Life Safety Department, whichis part of Respiratory Care. We havehad great success at improving patientsafety on non-critical care floors,Scott Slogic, RRT, RCP is Director of Life Support at Dartmouth-Hitchcock for the pasttwelve yearsreducing the number of intubationsand codes on the floors with this LifeSafety program, so we are thrilled withit. We started it three years ago.”Scott Slogic and his co-workers identifieda concept for standardizing from anotherindustry that was applicable withinhis own department: “I believe in theSouthwest Airlines model, with onestandard aircraft, the Boeing 737. Thismeans that every pilot, maintenanceengineer, every crew member knowshow to work on that plane. When there isan equipment change, they can substituteanother and it is seamless. It is anengineering concept that many placeshave bought into. For use, we bought intothe standardization of SERVO-i ventilator in2002. It took a couple of years to phase inbut we now have 50 SERVO-i ventilators.Everybody knows the ventilator and isfamiliar with it, physicians and nursesas well as the RT staff members.”The educational effortThe standardized ventilator solutionrequired an educational effort forrespiratory therapy staff members tolearn the new platform. Scott Slogicexplains: “Education was seamless,we do a lot of ongoing educationwith the SERVO –I. Every quarter wehave educational series specificallyabout unique aspects of the ventilator:internal functioning, application ofmodes, but we continuously educatethe staff on the ventilator. It is a fairlystraightforward platform to use,with a few idiosyncrasies, such asinspiratory cycle off when to use it andhow to tell if it is being used correctly.In future with NAVA, it probably won’tbe necessary. It was seamless forus. The universal application meanswe do everything between 500gram babies and 300 pound adults.Because of its flexibility, the SERVOventilator can be used for all patients”.Patient transport challengesin the pastAccording to Clinical Educator MattMcNally, RRT, the technology limitationsof solutions in the past would impact onpatient care, requiring interruption of thecircuit or the ventilation strategy. “Wedo upwards of 8 in-house transportsper day, not including the times wetransfer patients from the operatingroom to the ICU. In the past we wouldhave used either an antiquated ventilatorwhich required us to alter ventilatorsettings or oversedate the patient to help

36 | Critical Care Newsstabilize the patient, and then transfer tothe ICU without interrupting the circuitor ventilation strategy. The trauma roomis another place where we employ theseventilators. When a trauma is admitted,they are placed on the SERVO-i andventilation is not interrupted from theinitial application in the trauma bay, to theCAT scanner, then on to the ICU. Finally,one of our most crucial applicationsis in the neonatal resuscitation room.Recent literature supports the use ofa resuscitation system with the abilityto closely monitor and titrate ventilatorsettings which may result in betteroutcomes regarding broncho-pulmonarydysplasia and chronic lung disease. Byusing the SERVO-i, we feel that we candeliver consistent care from the deliveryroom to the NICU without interruption.”Scott Slogic with some of his staff membersthem tolerate the ventilator, or manualventilation with a resuscitation bag”.Scott Slogic concurs: “We would usean old model of transport ventilator,which provided basic ventilation, but weobviously could not ventilate the morecomplex patients well with this device.We eventually modified a SERVO 300ventilator by putting batteries underneathit and adding tanks, but that was a bigplatform and very unwieldy. For MRI,many may remember that there wasan article published in RespiratoryCare about how to modify the SERVO900C for use in MRI in order to do MRIventilation. We did that and it workedout pretty well, but the problem is thatit is a 30 year old platform that my staffhad to convert the patient to in the MRIand many of the younger staff memberswere not familiar with it. To be honest,we had two of them that got too close,even if they were modified. Beforethat, we were using basic pneumaticventilator, but it was very clear thatthere were patients that needed MRIthat we simply could not accommodateproperly. The settings would not beappropriate; we needed to ventilate themin the MRI environment just like weventilated them in the critical care unit.”The new solution – continuity ofcare in ventilation, even to the MRIOne of the advantages of standardizingto the SERVO-i ventilator was the abilityto transport patients within the facility.The ability to provide uninterruptedventilation to all patients is paramount,and continuity of care is the keyobjective according to Scott Slogicand Matt McNally, who explains: “Thisfeature has enabled us to provideuninterrupted ventilation to some ofthe sickest and most fragile patientsin the hospital. We use the SERVO-i totransport patients to and from diagnosticstudies and interventions includingCAT scan, MRI, X-ray, angiographyand the cardiac catheterization lab.”The new solution also provides someclinical advantages in patient transports,according to Matt McNally: “We are oftenrequested by anesthesia providers in theoperating room to assist with patientswho are difficult to ventilate. In thiscase, we are able to bring the SERVO-i,The new solution was also made tobe compatible for the 5 MRI suitesat Dartmouth-Hitchcock MedicalCenter. Scott Slogic describes theimplementation: “When we foundout that an MR-compatible SERVO-iwas available, it just made sense to ussince there would be no interruption inventilation, other than to transition themover to the MRI ventilator, and eventhen we learned. In the beginning, wethought that the SERVO MR compatibleventilators should be kept in the MRIdepartment, and that we would transitionthe patient down there. That procedureactually changed very quickly after onlya month or two. Now, we transitionthe patient right in the critical careunit to the MRI compatible ventilator,which makes for a seamless transportdown to the MRI department. The MRcompatible SERVO unit is used severaltimes each day, and is used on all sizesof patients, from infant and pediatrics toadults, and some larger adult patients.We do have MRI capabilities for largerpatients. For a typical MR transportprocedure there is one respiratorytherapist, one critical care nurse and twoorderlies that accompany the patient.”Scott Slogic also explained some of theclinical advantages that the new solutionprovides in MR transport situations:“With our particular procedure withthe SERVO- i. we transition the patientat the bedside in the critical care unitto the exact same settings on the MR

Critical Care News | 37BiographiesScott Slogic, RRT, received hiscertification in CardiopulmonaryScience at Parkland College, followedby his Bachelor of Science degreesin Respiratory Therapy and BusinessAdministration at St PetersburgCollege in Florida.The MR compatible SERVO-i ventilator is used in up to 8 transports a day at Dartmouth-Hitchcock Medical Centercompatible vent and monitor themfor a while to make sure that they arestable. Even if they are transferred tothe same settings there is the possibilityof in some cases with larger settingsto lose some lung volume very briefly,which should be recruited back up again.The transition down to the MRI unit isseamless after that. As we disconnectand reconnect, we might do a breathholdand pinch the endotracheal tube ina breath-hold maneuver and reconnectso they don’t lose lung volume. We don’tknow if that has an outcome effect,but it is a brief moment in time. We doknow from lung modeling that a breathor two off of significant amounts ofPEEP can mean lost amounts of lungvolume. In a really sick patient it doesnot take long to lose volumes, which iswhy we transition them at bedside inthe critical care unit, and monitor thembefore we go down to the MRI suite.”Future innovations in theDartmouth-Hitchcock RespiratoryCare DepartmentIn terms of ventilatory strategies at thepresent time, ARDSnet guidelines areused for patients who qualify for ARDS,according to Scott Slogic. “For non-ARDSpatients we ventilate usually in PressureSupport, and some level of PEEP that isappropriate for their Fi0 2 requirements,somewhere between 5 and 10 cmH 2 0 of PEEP. We analyze graphicsto determine if they need reducedinspiratory times, or have air trapping.The vast majority of our adult patientsare in Pressure Support, for our infantpatients we use SIMV with PressureControl for the most part, pediatrics area mix of Pressure Control and VolumeControl, depending on their condition.”“In future, we are pretty excited aboutstarting up Neurally Adjusted VentialtoryAssist, or NAVA. We have only used Edimonitoring on one patient so far, but weare going through the process of theeducational model with the physicians,step by step. We used it on an infantthat was asynchronous, to see if theasynchrony was real or not, and it was.It was more a matter of using the Edisignals diagnostically rather than runningthe NAVA ventilation mode, but weare really excited about it. Dr ChristerSinderby was here last year and spokeabout NAVA, when we heard about thisconcept, which is truly new in mechanicalventilation for us. Mechanical ventilationhas been kind of the same for the lastdecades, with maybe some variations onthe theme from a pneumatic perspective.In terms of mechanical ventilation, neuralventilation is truly unique. We don’tknow if it will change outcomes, but webelieve it has the potential to do so.”Scott Slogic has worked withinRespiratory therapy at St JosephsMedical Center in Bloomington, Illinoisand at the Bayfront Medical & TraumaCenter in St Petersburg, Florida.He joined the Dartmouth-HitchcockMedical Center in New Hampshire asStaff RCP in 1990, and was namedDirector of Respiratory Care in 1996as well as Director of Life Safety in2006. Scott Slogic has published anumber of scientific studies in peerreviewedcritical care publications.Matt McNally, RRT received hisBachelor of Science degree inRespiratory Care from QuinnipiacUniversity in Hamden Connecticut,and worked as Staff RespiratoryTherapist at Connecticut Children’sMedical Center from 1998-199,and was employed as RespiratoryTherapist Traveler with CrossCountry TravCorps from 1999-2001.Matthew McNally was employedby Dartmouth-Hitchcock MedicalCenter in Lebanon, New Hampshireas Transport Respiratory Therapistin 2002 and worked in that capacityuntil 2008, when he receivedhis current position as ClinicalEducator, Respiratory Care.The Dartmouth-Hitchcock MedicalCenter in New Hampshire, US

38 | Critical Care NewsJavier Garcia Fernandez, MD, PhD, works as a pediatric anesthesiologist at La Paz University Hospital in Madrid, SpainPeri-operative ventilation– What criteria are important for thewidest range of patients?Following the spring issue in which two European anesthesiologists were interviewed, Critical Care Newswas interested in meeting yet another clinician, this time in Spain, to hear what he had to say about themost important considerations in peri-operative ventilation mechanics for a wide range of patients.The University Hospital of La Paz is situated in the Fuencarral-El Pardo district of Madrid and is amulti-disciplinary public teaching hospital with focus on maternal and infant health care. La Paz isa reference hospital for all of Spain, as well as a reference burn center for pediatrics.Dr Javier Garcia Fernandez has done extensive research in ventilation mechanics and has developedan anesthesia simulator, making it thus easier to explain the principles of a circle system, as well asthe importance of certain principles that can have clinical implications.

Critical Care News | 39Dr Garcia is Head of the Pediatric Surgical Intensive Care UnitCan you tell us about yourprofessional background?My residency was done at the La Pazhospital in Madrid, after which I workedfor a year with adults in a generalhospital. After that year, I returned toLa Paz hospital and have been workingwith children; I have also earned an MBAin Sanitary Business Administration. Ihave been running the surgical IntensiveCare Unit in pediatrics for the past 2years. I am working both in the ICUand the department of anesthesia,and have been focusing on mechanicalventilation for the past 8 years.Can you tell us about yourresearch and publications in thefield of mechanical ventilation?My first research in anesthesia andmechanical ventilation, was about the useof Pressure Support inside the operatingroom. I wanted to try and transpose theknowledge from the critical care unit intothe world of the operating room, lookingat the differences between the usedventilatory modes, the clinical approachin using these modes, how one does themachine settings, and so on. The firstpoint was how to convince the rest ofmy colleagues on the use of the differentventilation modes which were of benefitto our patients and to simplify thesetechniques for the use in the operatingtheatre. After that I published two morearticles on how to set and use PressureSupport in the OR for children, as wellas the differences in PEEP settingsbetween adults and children in the OR.Most clinicians don’t want to use PEEPin the OR with children, because theyare afraid of the pressures they may beusing, even though they regularly applythem in the ICU. I realized that focusingon transferring this knowledge from theICU to the OR would make its use easier.How would you define high ventilatoryperformance in anesthesia and whatcriteria would you base it on?In order to give an appropriate definition,I would refer to the use of all theavailable ventilatory therapeutics whichare available in the ICU. Machines inthe ICU have improved notably in thelast ten years, but the advancementon anesthesia machines has notfollowed the same pace: here, thereare limitations. However, we have todayhigh risk patients entering the operatingtheatre, adults as well as children, elderlyand the very young, with high morbidityand critical situations, such as criticallyill patients, the morbidly obese, to namea few; among these are critical carepatients necessitating surgery, whosestatus is thought to be improved bysurgery. One special case is also verysmall children, who used to die severalyears ago but who, thanks to medicaland technical advancement, are now

40 | Critical Care NewsLa Paz University Hospital, Madrid, Spainsaved and given a chance to live throughsurgical procedures. These childrenundergo, at times, several procedures,and their prognosis remains critical.If one does not have access to thesame possibilities of ventilatory modesand techniques, and if moreover, onedoes not know how to use them inthe operating room, then the outcomecan really be compromised.What are the most commonlyperformed surgical procedureson neonates?Most often we see congenitalpathologies, such as esophageal atresia,or diaphragmatic hernia. But prematuresalso undergo surgical procedures fornecrotising enterocolitis and intestinalischemia, who in the past would die, andwho today survive thanks to advancessuch as intestinal transplants, thusallowing them to go forward in theirdevelopment. The number and success ofthese transplants is increasing, however,many of these children remain in acritical state, as they often have multiplepathologies, renal, hepatic, intestinal.When speaking about neonatalsurgery, do you define these casesas full term neonatal or pre-term?This question seems to me veryimportant. From the point of viewof mechanical ventilation, there areanesthesia machines which are notcapable of delivering the technologyneeded, based on the two fundamentalconditions: the weight of the patientand the condition of the lungs. If thebaby weighs less than 3 kilos, then it isoften difficult to ventilate, even in thehealthy lung. It can present altered lungs,pulmonary distress or hyaline membranesyndrome, something which worsensthe condition. The main problem withthis group of patients is that it is difficultto ventilate them. If one does not havethe same ventilatory performance inthe operating room as in the ICU, thenventilating becomes very difficult.What percent of the casesrepresent pre-term neonates?Nowadays, I must say 60%. The greatmajority of neonatal pathology has todo with premature babies. With eachtechnological advance in neonatal care,one was able to advance, or decreasethe survival weight with an extra 500-600 grams. Today, very tiny babies areoperated on more often than healthyneonates, with conditions such aspylorus defect or myelo-meningocele.These procedures can be done withoutcomplication on full-term babies, buton the very tiny prematures who havemulti-pathologies, intestinal, renal,respiratory and hepatic it is a challenge.

Critical Care News | 41They are often in much more criticalcondition than the healthy neonate.These children often end up inneonatal ICU post operatively.How important, according toyou, is the continuity of highventilation performance withrespect to their outcome?This is absolutely crucial. It can meanthe difference between survival anddeath. Whatever ventilatory changesoccur, or disconnection, not being ableto maintain a stable PEEP over time,can have the result of damaging theirfragile lungs; if these patients do notdie peri-operatively, they may well do sopost-operatively if there is no continuity.You have extensive experience inpediatric anesthesia. In which waydo you think pediatric anesthesiapractices can pave the way foroptimal adult anesthetic practice? Canpediatric anesthesia provide guidanceto the industry for developingmachines able to handle the comingchallenges in adult anesthesia?I believe this question is of the utmostimportance. The pulmonary physiologyof neonates gives us many answers.In the last 4-5 years, there have beenquestions concerning which tidal volumeshould one use in adults with distressedlungs? The recommended VT is thesame for these patients as for neonates,that is to say 6 ml/Kg. The other aspectis the use of PEEP. The best way ofavoiding atelectasis is the use of PEEP.You need to have a good understandingof neonatal pulmonary physiology toprevent atelectasis which occurs in allneonates; this knowledge can lead toknowledge on how to respond optimallyin adults. Neonatal lungs are the perfectmodel for respiratory distress in adults.The dynamic compliance of the lungsof a neonate (3 ml/cm H 2 O) is 6 timesless than in a highly distressed adultpatient (20 ml/cm H 2 O). If an anesthesiamachine can provide good ventilatoryperformance for a neonate, then it willbe able to adapt perfectly to the adultpatient needs, even in the case of thehighest pulmonary distress. PressureDr Garcia has developed an anesthesia simulator which helps in understandingventilation mechanics in a circle systemdelivery in the case of bronchospasmscan also be applied to both categories.One can also take the example of theobstetric patient whose lungs tend toeasily collapse, much as the neonatewho always suffers from atelectasis.Good recruitment possibilities inneonates ensure the same for adults.It is astonishing to me that moreanesthesiologists do not wonder aboutthe “potency” or power of the anesthesiaventilator. They often speak about thecolor of the windows on the interface,the size of the buttons, the alarms, howbig or small, how easy it is to movethe machine… But the power of theventilator… Why is that of importance?Much in the same way as in automobiles,acceleration can mean the differencebetween life and death in certain criticalsituations, such as bronchospasm,asthma, respiratory distress. The answerto these is the access to a full range ofsettings, like in the ICU. This will ensureproper ventilation for “this” patient. For“this” patient, in this critical situation,this aspect of high performance inventilation will be the most importantconsideration. Most patients have enoughwith a PEEP setting less than 20 cmH 2 O. But in certain cases, going above25 cm H 2 O will be a life-saving strategy,especially during a pulmonary recruitmanoeuvre. These aspects have to dowith patient safety. Maybe not manywill need it, but for the one who willneed it, it will be crucial! It represents aguarantee for the majority of the patients.It is also a question of confidence for theanaesthesiologist, trusting this particularmachine. With a traditional circuitsystem, one often goes over to manual/spontaneous ventilation in pediatrics,at the end of a procedure, because onefeels to have more control. This has alsodisadvantages. Mechanical ventilationis security for all ranges of patients.

42 | Critical Care NewsThe pediatric post-interventional care unit at La Paz HospitalWith respect to acquired knowledgein the field of anesthesia, whataspects would you consideras important to transmit?Inevitably, patient safety is the topquestion. One must know the basicsof mechanical ventilation. But that isnot enough. One must also understandthe differences between the circularcircuit versus the open circuit. Lackof this knowledge entails many extraproblems for the patient and theclinician. In the future, companies will“automatically” solve these questionsfor the practitioner, even if one doesn’tmaster these aspects, one will be ableto use the machine. However, it isnecessary to have a minimal knowledgeof advances in mechanical ventilationand physiological application.Could you please describe thesettings you would use in a3 Kg healthy neonate?Induction would generate respiratoryarrest and after intubation, one hasa situation of full lung atelectasis. Inorder to counter this problem, onehas to increase PEEP, after reachinghemodynamic stability, 5 by 5 cm H 2 O,all the while maintaining a driving pressureof no more than 15 cm H 2 O, until amaximum peak pressure of 35 cm H 2 O isreached, then with a PEEP of 20. Someneonates with severe distressed lungsoften need a maximum peak pressureof 45 cm H 2 O to open their lungs. Bywanting to limit the driving pressure to15 cm H 2 O, you must then increase thePEEP to 30 cm H 2 O. After which, youstart reducing the pressure and set theproper PEEP, adapted to the patient.One needs to have a wide range ofPEEP levels and maximum pressures.Could you please tell usabout what you think are theneeded ventilation modes?I have a very personal point of viewregarding this matter. About 5 years ago,very many ventilation modes appeared.It is crazy. When you think aboutit, Volume Control is the mostcommonly used. But Volume Controlis not enough; Pressure Control andVolume Control are mandatory today.Pressure Support is also beneficialfor the patient not needing musclerelaxation. It is better for the patient,the anesthesiologist and is easy to use.

Critical Care News | 43liters of fresh gas flow, as one spendsmuch more absorbent. The final reductionis much more expensive. And today,there are the risks of hypoxic mixtures.Some clinicians are however passionateabout low-flow, but cost savingsshould be calculated. As a conclusionI would like to say that it is importantfor clinicians to have knowledge aboutmechanical ventilation, as it lies at thecentre of patient safety. It is a powerfultool for avoiding negative iatrogeniceffects on patients; one must haveknowledge about the “open lung”, as wellas all protective strategies in ventilationduring anesthesia. The application of thisknowledge has been shown to reducemortality by 10-12%. These strategiesshould be applied to daily care.References1) Garcia-Fernandez, J. “Mechanicalventilation: learning fromneonates (EDITORIAL). Rev. Esp.Anestes Rean 2008; 55:1-3One of the care units in pediatricsWhat are your thoughtsabout trigger sensitivity?This is a critical question for pediatrics.Adults are used to thoracic pressuretrigger. Neonates or pre-terms needflow trigger, which allows perfectsynchronisation in time with therespiratory drive. Many machines todayhave a higher sensitivity giving informationmuch faster for a better adjustment.Advantages/disadvantages of existingbreathing systems in anesthesia?Companies have been more focusedon the flows, low-flow anesthesia thanon the ventilator itself, and I think thisis completely crazy. What are you usingthe machine for? It is to ventilate yourpatient safely. The power of insufflationis the focal point, then you can addother things like the rate of the freshgas flow used, how to save moneywith low-flow anesthesia….but thepriority is how well you are ventilating,and how safely. At this point, not manycompanies have thought about that:the anesthesia machines existing today,compared to critical care ventilatorshave power of insufflation representinghalf of that of ICU ventilators. We mustfocus on that, not losing this powerof insufflation, and not interruptingventilation, for the sake of patient safety.Recruitment is very important and themachines must be able to perform this.What are your thoughts about lowflowanesthesia? What are the limits?Low flow anesthesia is mandatory; butthe limit is the safety of the patient. Butthere are no savings between 0,5 and 0,32) Garcia-Fernandez J, TusmanG, Suarez F, Soro M, Llorens J,Belda J “Programming Pressuresupport ventilation in pediatricpatients in ambulatory surgery withlaryngeal mask”; Anesthesia &Analgesia 2007; 105: 1585-1591BiographiesJavier Garcia Fernandez, MD, PhDAnesthesiologist and Intensivist atthe University Hospital of La Pazin Madrid, Spain, where he hasbeen Head of the Department ofPediatric Surgical Intensive Carefor the past two years. Dr Garcia isalso the creator of an anesthesiasimulator called “Javierito”, whichhelps colleagues in understandingthe implication of peri-operativeventilation mechanics in patientcare. He has been doing researchin ventilation mechanics for thepast 8 years. Moreover, he haspublished articles in this domain.

NAVA is in the future of ventilationGet your free e-learning experienceFor a limited time only we are offering one free NAVA tutorial from our module-based,interactive SERVO educational program. Discover and e-learn the basics to get a deeperunderstanding of ventilation in the future, at your own pace, in your own time.Visit www.criticalcarenews.comand go to Tutorials - NAVA to get started!CRITICAL CARE NEWS is published by MAQUET Critical Care.Maquet Critical Care AB171 54 Solna, SwedenPhone: +46 (0)8 730 73 00www.maquet.com©Maquet Critical Care 2009. All rights reserved.Publisher: Fredrik WetterhallEditor-in-chief: Kris Rydholm ÖverbyContributing editor: Judith Marichalar-SundholmOrder No. MX-0554Printed in Swedenwww.criticalcarenews.cominfo@criticalcarenews.comThe views, opinions and assertions expressed in the interviewsare strictly those of the interviewed and do not necessarily reflector represent the views of Maquet Critical Care AB.©Maquet Critical Care AB, 2009.All rights reserved. No part of this publication may be reproduced,stored in a retrieval system, or transmitted in any form or by any othermeans, electronic, mechanical, photocopying, recording, or otherwise,without the prior written permission of the copyright owner.The following designations are registered or pendingtrademarks of MAQUET Critical Care AB: Servo-i®,Automode®, Open Lung Tool®, NAVA®