European Resuscitation Council Guidelines for Resuscitation ... - CPR

neurologically intact survival to hospital discharge. Biphasic waveformshave been shown to be superior to monophasic waveformsfor elective cardioversion of atrial fibrillation, with greater overallsuccess rates, using less cumulative energy and reducing the severityof cutaneous burns, 156–159 and are the waveform of choice forthis procedure.Energy levelsOptimal energy levels for both monophasic and biphasic waveformsare unknown. The recommendations for energy levels arebased on a consensus following careful review of the current literature.First shockThere are no new published studies looking at the optimalenergy levels for monophasic waveforms since publication of the2005 guidelines. Relatively few studies on biphasic waveforms havebeen published in the past 5 years on which to refine the 2005guidelines. There is no evidence that one biphasic waveform ordevice is more effective than another. First shock efficacy of thebiphasic truncated exponential (BTE) waveform using 150–200 Jhas been reported as 86–98%. 153,154,160–162 First shock efficacyof the rectilinear biphasic (RLB) waveform using 120 J is up to85% (data not published in the paper but supplied by personnelcommunication). 155 Two studies have suggested equivalencewith lower and higher starting energy biphasic defibrillation. 163,164Although human studies have not shown harm (raised biomarkers,ECG changes, ejection fraction) from any biphasic waveform up to360 J, 163,165 several animal studies have suggested the potential forharm with higher energy levels. 166–169The initial biphasic shock should be no lower than 120 J for RLBwaveforms and 150 J for BTE waveforms. Ideally, the initial biphasicshock energy should be at least 150 J for all waveforms.Second and subsequent shocksThe 2005 guidelines recommended either a fixed or escalatingenergy strategy for defibrillation and there is no evidence to changethis recommendation.CardioversionIf electrical cardioversion is used to convert atrial or ventriculartachyarrhythmias, the shock must be synchronised to occurwith the R wave of the electrocardiogram rather than with the Twave: VF can be induced if a shock is delivered during the relativerefractory portion of the cardiac cycle. 170 Biphasic waveformsare more effective than monophasic waveforms for cardioversionof AF. 156–159 Commencing at high energy levels does not improvecardioversion rates compared with lower energy levels. 156,171–176An initial synchronised shock of 120–150 J, escalating if necessaryis a reasonable strategy based on current data. Atrial flutter andparoxysmal SVT generally require less energy than atrial fibrillationfor cardioversion. 175 Give an initial shock of 100 J monophasic or70–120 J biphasic. Give subsequent shocks using stepwise increasesin energy. 177 The energy required for cardioversion of VT dependson the morphological characteristics and rate of the arrhythmia. 178Use biphasic energy levels of 120–150 J for the initial shock. Considerstepwise increases if the first shock fails to achieve sinusrhythm. 17818 de 0ctubre de 2010 www.elsuapdetodos.comJ.P. Nolan et al. / Resuscitation 81 (2010) 1219–1276 1229(see Advanced life support). 6 Immediate pacing is indicated especiallywhen the block is at or below the His-Purkinje level. Iftransthoracic pacing is ineffective, consider transvenous pacing.Implantable cardioverter defibrillatorsImplantable cardioverter defibrillators (ICDs) are implantedbecause a patient is considered to be at risk from, or has had, a lifethreateningshockable arrhythmia. On sensing a shockable rhythm,an ICD will discharge approximately 40 J through an internal pacingwire embedded in the right ventricle. On detecting VF/VT, ICDdevices will discharge no more than eight times, but may reset ifthey detect a new period of VF/VT. Discharge of an ICD may causepectoral muscle contraction in the patient, and shocks to the rescuerhave been documented. 179 In view of the low energy levelsdischarged by ICDs, it is unlikely that any harm will come to therescuer, but the wearing of gloves and minimising contact with thepatient while the device is discharging is prudent.Adult advanced life supportPrevention of in-hospital cardiac arrestEarly recognition of the deteriorating patient and preventionof cardiac arrest is the first link in the Chain of Survival. 180 Oncecardiac arrest occurs, fewer than 20% of patients having an inhospitalcardiac arrest will survive to go home. 36,181,182 Preventionof in-hospital cardiac arrest requires staff education, monitoring ofpatients, recognition of patient deterioration, a system to call forhelp and an effective response. 183The problemCardiac arrest in patients in unmonitored ward areas is notusually a sudden unpredictable event, nor is it usually causedby primary cardiac disease. 184 These patients often have slowand progressive physiological deterioration, involving hypoxaemiaand hypotension that is unnoticed by staff, or is recognised buttreated poorly. 185–187 Many of these patients have unmonitoredarrests, and the underlying cardiac arrest rhythm is usually nonshockable182,188 ; survival to hospital discharge is poor. 36,181,188Education in acute carewww.elsuapdetodos.comStaff education is an essential part of implementing a system toprevent cardiac arrest. 189 In an Australian study, virtually all theimprovement in the hospital cardiac arrest rate occurred duringthe educational phase of implementation of a medical emergencyteam (MET) system. 190,191Monitoring and recognition of the critically ill patientTo assist in the early detection of critical illness, each patientshould have a documented plan for vital signs monitoring thatidentifies which variables need to be measured and the frequencyof measurement. 192 Many hospitals now use early warning scores(EWS) or calling criteria to identify the need to escalate monitoring,treatment, or to call for expert help (‘track and trigger’). 193–197The response to critical illnessPacingConsider pacing in patients with symptomatic bradycardiarefractory to anti-cholinergic drugs or other second line therapyThe response to patients who are critically ill or who areat risk of becoming critically ill is usually provided by medicalemergency teams (MET), rapid response teams (RRT), or criticalcare outreach teams (CCOT). 198–200 These teams replace or coexist