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172 Australasian Anaesthesia 2011Perioperative Transthoracic Echocardiography in Australasia: Current Position and Future Directions 173warning sign of haemodynamic instability, but does not identify the cause.The potential advantages of goal directed studies should not be understated. In anaesthesia, when faced withEchocardiography can be used to identify patterns of abnormality (such as hypovolaemia), systolic failure ora systolic murmur, it is important 23 to exclude haemodynamically significant aortic stenosis with reasonable certainty.vasodilatation), and when integrated with the clinical scenario, can help identify the cause of haemodynamicThis cannot be done clinically. A review by Etchells and colleagues, 24 showed that while effort syncope with ainstability. Royse has described a methodology for the evaluation of haemodynamic state using limited TTE. 1systolic murmur has the highest positive predictive value, the lack of effort syncope is not helpful in differentiatingCritically ill patients require urgent diagnosis. This is facilitated if the practitioner managing the patient performssevere aortic stenosis. The lack of radiation of the murmur to the right carotid is the most useful of the negativethe TTE, rather than relying on third party providers such as cardiology, where timely access to their services mayclinical sign, but there is a false negative rate of 5 – 10%. They showed cardiologists are better than non cardiologists,be limited or not available.but that even cardiologists were no better than about 90% certain. Reichlin et al 25 assessed the ability of emergencyA third use of cardiac ultrasound is as a perioperative haemodynamic monitor. Echocardiography allows thephysicians to diagnose systolic murmurs. The study included 203 consecutive patients admitted to an emergencyassessment of both right and left sided preload, of right and left ventricular systolic and diastolic function, ofdepartment and noted to have a systolic murmur. Some 35% of these had significant valvular heart disease shownpulmonary artery pressures (in most cases) and of cardiac output. No other haemodynamic monitor is able toon TTE within an hour of the clinical examination (equal distribution of mitral regurgitation, aortic stenosis and othermeasure all of these parameters. TTE, unlike either TOE or a pulmonary artery catheter, is non-invasive and therelesions). Sensitivity and specificity for the correct diagnosis by clinical examination were only 82% andare no safety issues in image acquisition. It can also be used in an awake patient. Other monitors using pulse69% respectively.pressure variation or transoesophageal doppler devices are arguably easier to use but provide a less completeIn 1975 using M-mode echocardiography, Weyman and Feigenbaum 26 showed that a cusp separation of 15mmpicture. An example of using TTE for haemodynamic monitoring during a caesarean section is described by Fergusonor more in the parasternal long axis view excludes moderate or severe aortic stenosis. Since then 2D imaging haset al. 2dramatically improved, and restricted leaflet movement in the parasternal long and short axis views readily identifiesFourthly, the anaesthetic perspective should be born in mind. It is rare for a cardiac sonographer or cardiologisthaemodynamically significant moderate or severe aortic stenosis.to have patient in whom there are sudden and significant changes in preload, afterload or contractility, as occursThere is controversy regarding qualitative versus quantitative grading of ventricular function or valve lesions. Ifduring anaesthesia. Anaesthetists will view echocardiograms with a different perspective to cardiologists, focusinglong term trends are important, then quantification is important. For example, if a patient has had a myocardialon ventricular function and haemodynamically important valve lesions to answer specific questions, rather than ainfarction and an ejection fraction of 40%, they may be put on an angiotensin converting enzyme inhibitor. In threecomprehensive study aimed at identifying all aspects of the echocardiogram.months a cardiologist will be interested if the ejection fraction is now 35, 40 or 45%. But in anaesthesia, all haveLearning to perform and interpret echocardiography requires an additional knowledge base that is not currentlyabout the same degree of systolic impairment. An anaesthetist wants to know if the systolic function of a heart ispart of anaesthesia training. Performing echocardiography also provides the practitioner with a powerful feedbacknormal, somewhat impaired or severely impaired. These patterns are easy to distinguish by 2D pattern recognitiontool, which serves to improve understanding of the pathophysiology and how anaesthesia influences it. Manyalone. With aortic stenosis, we are accustomed to peak and mean gradients and aortic valve area. But do we reallyanaesthetists read only the conclusions of formal report, but the black and white conclusions often hide a greaterneed this data? Anaesthetists need to know whether the stenosis could be haemodynamically significant, so thatsubtlety in the numbers, findings and the interpretation of the study. The anaesthetic paradigm mentioned earlierwe can plan the anaesthetic and postoperative care appropriately. In elective surgery, quantification may be importantcan result in a different interpretation for our specialty even though the conclusions are totally appropriate from ain those few cases in which it would be more appropriate to consider valve surgery prior to their planned operation.cardiology perspective.But when surgery is urgent and there is little choice but to proceed and anaesthetists will treat moderate and severeAn example could be a report of a large pericardial effusion without echocardiographic evidence of tamponade.stenosis in a similar manner.In another personal example, the patient had undergone a pericardial window 1 month earlier. The cardiologist hadQuantification for less experienced operators also has the potential to underestimate severity. The jets are oftenreassured the surgeon that tamponade was no longer a risk. The anaesthetist performed a limited TTE and identifiedeccentric and may require the use of non-standard views to obtain the peak velocity and the use of a non-imaginga warning sign of a small degree of right atrial collapse, leading the anaesthetist to consider tamponade a significantprobe. If the peak velocity is not interrogated, the valve area is overestimated and gradients underestimated. Anrisk during the forthcoming anaesthetic. A 1500 mL fluid loading and vasopressor with the induction was administered.area of active research in preoperative assessment is to determine the learning curves required for the safeDespite this, there was a significant, but not life threatening, haemodynamic change on induction. The echo findingsquantification of aortic stenosis in comparison to qualitative 2D and colour flow pattern recognition. In a small studywere the same for both cardiologist and anaesthetist, but the images were seen from a different perspective.by Cowie et al, 27 TTE naïve anaesthetic trainees were able to measure peak velocity and potentially gain usefulinformation in addition to that available from 2D and colour flow imaging alone.GOAL DIRECTED CARDIAC ULTRASOUNDEchocardiography examinations performed by cardiology services are (almost always) comprehensive diagnosticTRAINING IN TTE FOR ANAESTHETISTS IN AUSTRALASIAstudies. Studies are conducted for other practitioners and, irrespective of the indications for a study, the expectationThe penetration of TTE into anaesthesia can be gauged by training numbers. Courses, conferences and workshopsis that all findings will be included in the report. Conversely, in anaesthesia, echocardiography is an extension ofin TOE appeared in the late 1990s. Formal training was offered in Australia in 2004 with the establishment of athe clinical assessment. The echo results are often directly and immediately integrated with other clinical information.Postgraduate Diploma in Perioperative and Critical Care Echocardiography by the University of Melbourne (PGDipEcho).Cardiologists need to follow trends overtime so quantification is important, but in anaesthesia, long term trendsThe original diploma included a component of TTE, but was largely designed for cardiac anaesthetists performingare unimportant and a qualitative assessment will often suffice, especially in time critical situations.TOE. The call for training for general anaesthetists and TTE resulted in modifications in 2009. The first six monthsThese differences have led to a paradigm of goal-directed studies to answer only one or more specific clinicalbecame a Postgraduate Certificate in Clinical Ultrasound (PGCertCU) with a strong emphasis on TTE with TOEquestions (and often no more). Terms such as limited or focused, bed-side or point of care are also used becauselargely consigned to a second six months now a Postgraduate Diploma in Clinical Ultrasound (PGDipCU). Theof their location, or hand-held because of the equipment often used. 3,4knowledge base for the PGCertCU is aimed at “a good basic sonographer” and the PGDipCU at “diagnostic level”.They may take only five minutes while a comprehensive study may take half an hour. Goal-directed studies mayTo date 460 clinicians have completed the PGDipEcho, 297 have completed the PGCertCU with another 135only use one or two echocardiographic windows and fewer than the expected number of views through eachenrolled. Forty-nine have now completed the PGDipCU with 40 more enrolled.window than would be expected in a comprehensive study. Quantification may be minimal or non-existent, patternFor skills based (i.e. hands-on) TTE training, the University of Melbourne has offered a large number of workshops.recognition being more important than measurement. A goal-directed study may need no more than 2D imaging ifThe Point of Care Courses which ran from 2005 to 2009 (353 participants), included two stations (about 40%) ononly haemodynamic state needs to be assessed, while a global assessment of valvular function requires colourTTE. Since 2005, the H.A.R.T.Scan courses have provided training in goal-directed TTE for 577 doctors. The majorityflow imaging as well. The term “cardiac ultrasound” is used by some to cover both types of examination while theof doctors attending these courses have been anaesthetists.term “echocardiography” is reserved by others for comprehensive studies only.Alternative qualifications are also available. The National Board of Echocardiography in the USA has examinationsThere are some issues with goal-directed studies. First, it must be accepted that some information will be missed.and certification (but no specific training courses) in perioperative transoesophageal echocardiography (PTXeXAM)A study by Rugolotto et al 5 showed that using clinical examination alone, a cardiologist missed some 40% ofand in adult echocardiography (ASCeXAM). The PTXeXAM is designed for cardiac anaesthetists while the ASCeXAMsignificant abnormalities when compared with a comprehensive TTE. Using a hand-held bedside cardiac ultrasoundis for cardiologists. There are 90 physicians in Australia and 25 in New Zealand with the PTXeXAM and 2 anaesthetistswith 2D and colour flow Doppler capabilities only, they still missed 20% of significant abnormalities. However, bywith the ASCeXAM.using the results of the bedside study they were able to institute earlier treatment and discharge patients a dayThe Australian Society of Ultrasound Medicine (ASUM) offers a Diploma in Diagnostic Ultrasound with an optionearlier on average. Importantly, the authors reported no errors in treatment using the bedside studies. Other studiesof cardiac ultrasound. This course has both knowledge and skills base training. ASUM also provides one of thehave had similar findings. 6-8 Missed information is potentially important but may not be significant in critical care.primary qualifications held by sonographers in Australasia. Other universities are starting to offer training andA minor regional wall motion abnormality might be missed, but will not be the cause of haemodynamic collapse.qualifications that could be of interest to goal-directed TTE.There is an increasing body of evidence for the efficacy of point of care, physician and sonographer performed,Comprehensive echocardiography requires extensive training and experience. The joint American College ofgoal directed studies, using with portable or hand carried machine. These studies are in many fields includingCardiology and America Heart Association (ACC/AHA) guidelines on the clinical competence 28 require a minimumcardiology, 7,9,10 general medicine, 11 emergency medicine (many specialties), 12-14 intensive care 15-18 and anaesthesia, 19,20of 150 personally performed and an additional 300 supervised reports for independent practice. However, manyHowever, not all authors agree its utility in all fields or all circumstances. 21,22 studies have shown that goal-directed TTE can be taught with significantly less training, but with the proviso thatany findings may also be limited and integrated with other clinical information as discussed earlier.
174 Australasian Anaesthesia 2011Perioperative Transthoracic Echocardiography in Australasia: Current Position and Future Directions 175Royse et al 29 studied the learning curve in an echo naïve medical student. They showed 20 studies were requiredto conduct a basic haemodynamic state assessment. Price et al 30 studied physicians attending a one-day trainingcourse in peri-resuscitation echocardiography. A test of knowledge base showed an improvement in imageinterpretation (pre 62%, post 78%, p < 0.01) and 100% of participants were able to obtain a subcostal view ofdiagnostic quality by the end of the course, most in under 10 sec.Vignon et al 30 reported on the efficacy of training of naïve non-cardiology residents in limited echocardiographyin an ICU. Each was given 3 hours of lectures and 5 hours of hands on training. In a study of 61 consecutive patientsand comparing residents with an experienced intensivist, they were significantly slower and answered significantlyfewer of the 366 clinical questions (3 vs. 27%). However, when addressed, left ventricular systolic function, left andright ventricular dilatation, pericardial effusion and tamponade were all correctly appraised.Hellman et al 31 reported on the training of 31 residents in the use of a hand carried cardiac ultrasound machinefor limited echocardiographic studies. They were given a 30 minutes lecture followed by one-on-one instructionand supervision. A linear regression model plotting an overall assessment index against the number of scansshowed a learning curve of 20 – 40 scans. However, the authors did note significant differences between residentsin their rate of learning.These studies show that goal-directed limited transthoracic echocardiography is within the reasonable reachof a significant proportion of the anaesthetic community.TTE IN AUSTRALASIAN ANAESTHESIASome specific examples give an overview of TTE usage in Australasian anaesthesia. The first case series wasreported by Canty et al in 2009 20 . They reported on 87 TTE and 14 TOE examinations in 97 patients at Royal HobartHospital (75 studies were conducted pre-operatively). Three patients had their surgery changed or cancelled, andin 18 patients there were significant changes in anaesthetic management.Cowie in 2011 19 , at St Vincent’s Hospital in Melbourne, has reported on three years’ experience in anaesthetistsperformed goal-directed echocardiography. He reports adequate images obtainable in 167 out of 170 patients(98%). Just over half the studies were conducted because of a systolic murmur. Changes in peri-operativemanagement occurred in 140 out of 170 (82%) patients. Major findings correlated with a formal cardiologytransthoracic echocardiogram in 52 out of 57 (92%) patients.Joondalup Hospital in Perth has established a formal perioperative echocardiography service. Comprehensiveechocardiograms are conducted by a cardiac sonographer and reported by an anaesthetist. The most commonindications are undiagnosed systolic murmurs or poor exercise tolerance (or an inability to assess it). If anechocardiogram has been conducted elsewhere in the preceding year and a copy of the report can be obtained,it is not repeated unless there is a specific indication to do so. Abnormal findings are referred to cardiologists forfollow up with the images and report provided so that the study does not need to be repeated.In the first 22 months, nearly 700 echocardiograms have been performed. Preliminary results show 26.7% ofpatients had moderate or severe echocardiographic findings such as significant valvular dysfunction or valvularheart disease. Half of these findings were totally unexpected on clinical grounds. Around 36% of the murmurs werethe results of moderate or severe disease. In sixty patients with a murmur, surgery proceeded as planned becausehaemodynamically significant valvular heart disease was confidently excluded.Sir Charles Gairdner Hospital, also in Perth, has embraced all forms of ultrasound. One third of the consultantstaff have experience and a formal qualification in echocardiography with others in training. The majority are generalanaesthetists and most perform only TTE, while three are cardiac anaesthetists practicing only TOE (with two moremeeting the “grandfather” requirements of PS46 32 ). The department has seven TTE capable ultrasound machines.Both limited goal-directed and comprehensive echocardiograms have been conducted as required over the pastfive years. The hospital is considering extending anaesthetist performed goal-directed limited examinations to thepreoperative clinic on a more regular basis. With two different models being used in the one city, it is hoped to beable to compare and contrast the efficacy and community costs of each model.THE NEXT CASESo you performed a goal-directed TTE for our elderly gentleman who fell and injured his lower leg. This showed aheavily calcified aortic valve with an obvious restriction in opening. In addition, there was mild to moderate aorticregurgitation, obvious concentric left ventricular hypertrophy, hypokinesis of the inferior septal wall (consistent withan old right coronary artery territory myocardial infarction) and a huge left atrium typical of significant diastolicimpairment. Further questioning of the patient revealed a couple of episodes of possible syncope. Although hewalked the dog every day, the dog walked but he rode in a buggy. Although the ejection fraction appeared to berelatively well preserved and the peak and mean gradients across the valve were only 39 and 26mmHg pressurein the moderate range, the aortic valve area was 0.6cm 2 and dimensionless index 0.20, 33 both suggesting severeif not critical aortic stenosis. However, the 2D appearance was that of severe, not just moderate stenosis, consistentwith normal ejection fraction low-gradient severe aortic stenosis. Despite initial patient reluctance, the surgery wassuccessfully conducted under local anaesthesia.REFERENCES AND FOOTNOTES1. Royse CF: Ultrasound-guided haemodynamic state assessment. Best practice & research. Clinicalanaesthesiology 2009; 23: 273-83.2. Ferguson EA, Paech MJ, Veltman MG: Hypertrophic cardiomyopathy and caesarean section: intraoperative useof transthoracic echocardiography. International journal of obstetric anesthesia 2006; 15: 311-6.3. Faris JG, Veltman MG, Royse CF: Limited transthoracic echocardiography assessment in anaesthesia andcritical care. Best Pract Res Clin Anaesthesiol 2009; 23: 285-98.4. Cowie B: Focused cardiovascular ultrasound performed by anesthesiologists in the perioperative period: feasibleand alters patient management. J Cardiothorac Vasc Anesth 2009; 23: 450-6.5. Rugolotto M, Chang CP, Hu B, Schnittger I, Liang DH: Clinical use of cardiac ultrasound performed with a handcarrieddevice in patients admitted for acute cardiac care. Am J Cardiol 2002; 90: 1040-2.6. Prinz C, Voigt JU: Diagnostic accuracy of a hand-held ultrasound scanner in routine patients referred forechocardiography. J Am Soc Echocardiogr 2011; 24: 111-6.7. Giusca S, Jurcut R, Ticulescu R, Dumitru D, Vladaia A, Savu O, Voican A, Popescu BA, Ginghina C: Accuracyof handheld echocardiography for bedside diagnostic evaluation in a tertiary cardiology center: comparisonwith standard echocardiography. Echocardiography 2011; 28: 136-41.8. Culp BC, Mock JD, Chiles CD, Culp WC, Jr.: The pocket echocardiograph: validation and feasibility.Echocardiography 2010; 27: 759-64.9. Kimura BJ, Yogo N, O’Connell CW, Phan JN, Showalter BK, Wolfson T: Cardiopulmonary Limited UltrasoundExamination for “Quick-Look” Bedside Application. Am J Cardiol 2011.10. Cardim N, Fernandez Golfin C, Ferreira D, Aubele A, Toste J, Cobos MA, Carmelo V, Nunes I, Oliveira AG,Zamorano J: Usefulness of a new miniaturized echocardiographic system in outpatient cardiology consultations asan extension of physical examination. Journal of the American Society of Echocardiography : official publicationof the American Society of Echocardiography 2011; 24: 117-24.11. Potter A: Echocardiography in acute medicine: a clinical review. Br J Hosp Med (Lond) 2010; 71: 626-30.12. Breitkreutz R, Price S, Steiger HV, Seeger FH, Ilper H, Ackermann H, Rudolph M, Uddin S, Weigand MA, MullerE, Walcher F: Focused echocardiographic evaluation in life support and peri-resuscitation of emergency patients:a prospective trial. Resuscitation 2010; 81: 1527-33.13. Kirkpatrick A: Clinician-performed focused sonography for the resuscitation of trauma. Critical Care Medicine2007; 35: S162-S172.14. Breitkreutz R, Walcher F, Seeger FH: Focused echocardiographic evaluation in resuscitation management:concept of an advanced life support-conformed algorithm. Crit Care Med 2007; 35: S150-61.15. Stawicki SP, Braslow BM, Panebianco NL, Kirkpatrick JN, Gracias VH, Hayden GE, Dean AJ: Intensivist use ofhand-carried ultrasonography to measure IVC collapsibility in estimating intravascular volume status: correlationswith CVP. J Am Coll Surg 2009; 209: 55-61.16. Sloth E, Larsen KM, Schmidt MB, Jensen MB: Focused application of ultrasound in critical care medicine.Crit Care Med 2008; 36: 653-4; author reply 654-5.17. Guillory RK, Gunter OL: Ultrasound in the surgical intensive care unit. Curr Opin Crit Care 2008; 14: 415-22.18. Beaulieu Y: Bedside echocardiography in the assessment of the critically ill. Crit Care Med 2007; 35: S235-49.19. Cowie B: Three years’ experience of focused cardiovascular ultrasound in the peri-operative period. Anaesthesia2011; 66: 268-73.20. anty DJ, Royse CF: Audit of anaesthetist-performed echocardiography on perioperative management decisionsfor non-cardiac surgery. Br J Anaesth 2009; 103: 352-8.21. Lucas BP, Candotti C, Margeta B, Mba B, Kumapley R, Asmar A, Franco-Sadud R, Baru J, Acob C, BorkowskyS, Evans AT: Hand-Carried Echocardiography by Hospitalists: A Randomized Trial. Am J Med 2011.22. Kansal M, Kessler C, Frazin L: Hand-held echocardiogram does not aid in triaging chest pain patients from theemergency department. Echocardiography 2009; 26: 625-9.23. Torsher LC, Shub C, Rettke SR, Brown DL: Risk of patients with severe aortic stenosis undergoing noncardiacsurgery. The American journal of cardiology 1998; 81: 448-52.24. Etchells E, Bell C, Robb K: Does this patient have an abnormal systolic murmur? JAMA : the journal of theAmerican Medical Association 1997; 277: 564-71.25. Reichlin S, Dieterle T, Camli C, Leimenstoll B, Schoenenberger RA, Martina B: Initial clinical evaluation of cardiacsystolic murmurs in the ED by noncardiologists. The American journal of emergency medicine 2004; 22: 71-5.26. Weyman AE, Feigebaum H, Dillon JC, Chang S: Cross-sectional echocardiography in assessing the severity ofvalvular aortic stenosis. Circulation 1975; 52: 828-34.
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