Interact CardioVasc Thorac Surg 2007;6:799-805. doi:10.1510/icvts.2007.163899
© 2007 European Association of Cardio-Thoracic Surgery
Best evidence topic - Arrhythmia |
What cardioversion protocol for ventricular fibrillation should be followed for patients who arrest shortly post-cardiac surgery?
Lydia Richardsona,
Arosha Dissanayakeb and
Joel Dunninga,*
a Department of Cardiothoracic Surgery, James Cook University Hospital, Middlesbrough, UK
b School of Health, University of Durham, UK
Received 25 July 2007;
accepted 26 July 2007
*Corresponding author. Tel./fax: +44-780-1548122.
E-mail address: joeldunning{at}doctors.org.uk (J. Dunning).
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Abstract
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A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was how many cardioversion attempts should be performed for patients who have gone into ventricular fibrillation post-cardiac surgery prior to performing chest reopening. Using the reported search, 1183 papers were identified. Fifteen papers represented the best evidence on the subject. The author, journal, date and country of publication, patient group studied, study type, relevant outcomes, results and study comments and weaknesses were tabulated. The quality and level of evidence was assessed using the International Liaison Committee of Resuscitation guideline recommendations. The most recent European Resuscitation Council guidelines suggest single attempts at cardioversion, spaced at 2-min intervals, for all patients going into ventricular fibrillation or pulseless ventricular tachycardia. Cardiac surgery presents a unique challenge for these guidelines in that emergency re-sternotomy may provide additional lifesaving interventions once it is deemed that external cardioversion is unlikely to succeed. The 15 papers identified demonstrated that the success of the first attempt at cardioversion for VF/VT was around 78%. The chance of the second shock succeeding was around 35%. The chance of a third shock succeeding was 14%. Very little data were found on the chance of further shocks succeeding. Of note none of these papers were in patients on the intensive care after cardiac surgery. We conclude that, due to the importance of minimising the delay to chest reopening, three shocks should be quickly delivered. If these do not succeed the chance of a 4th shock succeeding is likely to be <10% and, thus, immediate chest reopening should be performed. (This is a Class-IIa recommendation using ILCOR guideline recommendations.)
Key Words: Cardiothoracic surgery; Defibrillation; Automatic external defibrillator; Ventricular fibrillation
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1. Introduction
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A best evidence topic was constructed according to a structured protocol, described in the ICVTS [1]. The quality of each study was assessed using the International Liaison Committee on Resuscitation (ILCOR) 2005 protocol [20].
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2. Clinical scenario
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A 78-year-old patient has returned to your intensive care following a quadruple coronary arterial bypass graft. The operation note states that the targets were very small and there is some lateral ST segment elevation on the monitor. One hour post-surgery he suddenly goes into ventricular fibrillation. The nurses start to massage the patient. You place external pads on the patient and deliver a single 150 J biphasic shock which is unsuccessful. You start to charge for a second shock but the nurses who have just gone on a resuscitation update course recommence cardiac massage and tell you that he needs 2 min of massage. You are aware that a graft may be kinked or occluded or there may be a tamponade and, thus, do not want to delay reopening, but to not want to reopen after a single failed shock, and later resolve to look up how many shocks we should perform prior to reopening.
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3. Three-part question
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In [patients who go into VF post-cardiac surgery], what is the success rate of each subsequent [defibrillatory shock] to return [cardiac output]?
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4. Search strategy
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Medline 1950 to August 2007 using OVID Interface.
[exp cardiac surgical procedures/OR exp thoracic surgical procedures/OR exp thoracic surgery/] AND [exp ventricular fibrillation/OR exp Tachycardia, Ventricular/] AND [exp Electric Countershock/OR Heart Arrest/OR exp Cardiopulmonary Resuscitation/]. Embase 1980 to August 2007 [exp Heart sugery/OR exp Thorax Surgery] AND [exp heart ventricle Fibrillation/OR exp Heart Ventricle Tachycardia/] AND [exp heart arrest/OR exp resuscitation/OR exp cardioversion/]. All references searched from Section 2 and 3 of the European Resuscitation Council Guidelines for Resuscitation 2005 [2, 3].
Cochrane Database of Systematic reviews was searched on 28th of August 2007 using the search term ‘resuscitation’ searched. Cochrane Controlled Trials register searched on 28th of August 2007 using the search term ‘resuscitation’.
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5. Search outcome
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Four hundred and eighty-six abstracts were identified from Medline, 352 abstracts from Embase, 28 papers from the Cochrane database of systematic reviews and 155 from the Cochrane controlled trials register. There were 162 references in sections 2 and 3 of the ERC guidelines. From these studies, 15 represented the best evidence on the topic (Table 1).
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6. Comments
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Current guidelines from the European Resuscitation Council [2, 3] state that 2 min should be left between attempts at cardioversion for patients who arrest and go into ventricular fibrillation or ventricular tachycardia (VF/VT). But in patients post-cardiac surgery, prompt chest reopening is known to improve outcomes, thus, waiting for 2 min between each shock may result in a delay that may impair outcome should cardioversion prove unsuccessful. Therefore, having a protocol for the number of attempts at defibrillation prior to reopening the chest is of paramount importance.
In eight studies [4, 5, 7–9, 11, 15, 17], monophasic shocks were compared to biphasic shocks, and in all these papers, biphasic shocks were found to be more successful or equivalent to monophasic shocks at defibrillation. In five [4, 5, 7, 15, 17] of these comparative studies, the success at the first attempt at defibrillation was between 86 and 98%. In contrast, two of the studies [8, 9] showed relatively lower first shock success rates ranging from 16.7 to 22.9%. However, in one of the latter studies by Schwartz et al. [9], intra-operative shocks were delivered during cardiac surgery on 91 patients, therefore, the first shock energy was lower at 2 J compared to the higher energies (100–150 J) used for the transthoracic delivery in the other studies.
Two animal studies were performed. Cammarata et al. [13] induced VF in 60 pigs, then delivered three sequential 150 J biphasic shocks. The first shock success was 80%, which steeply declined to 15% success for the second shock and further dropped to 5% for the third shock success. These results strongly suggest that a maximum of three shocks should be delivered to patients in VF/VT, as after this point, the chance of successful defibrillation is very small. The second study was by Nieman et al. [14], who induced VF in 38 pigs, who either received three escalating monophasic shocks (200-300-360 J) or fixed biphasic shocks (150 J). Both shock waveforms displayed a similar reduction in shock success from first to third shocks. The first shock success was 50% for biphasic shocks, followed by 30% for second shock and 5% at third shock. The results of both papers suggest that the fourth shock success would be below 5%. These animal studies have the obvious limitation of involving pigs as the subjects, however, in combination (98 pigs) the similar pattern of reduction from first to third shock success indicates that proceeding to a fourth shock would not be beneficial to patients in VF.
Of course we must acknowledge the wide range of papers from which we obtained these data, including papers looking at ICDs, electrophysiological studies, all the way to out-of-hospital arrests and animal studies and we must furthermore acknowledge that the success of a second shock after 2 min of CPR has not yet been reported in any paper that we found. However, when the data are combined from all 15 papers, although not all record the second and third shock success, the average success rate of sequential shocks declines from 77.6% for the first shock, 34.8% for the second shock and to 13.9% for third shock success. Data on fourth shock success was only recorded in one paper [9]. Overall, the data suggest that the likelihood of conversion from VF/VT to an organised rhythm declines dramatically from first to second shock, and declines further from second to third shock, which indicates that proceeding to reopening after the third shock is preferable due to the minimal chance of fourth shock success. Mackay et al. [19] reported the results of 79 chest reopenings over six years and found that the major determinant of survival was chest reopening within 10 min.
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7. Clinical bottom line
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We conclude that due to the importance of minimising the delay to chest reopening, three shocks should be quickly delivered. If these do not succeed the chance of a 4th shock succeeding is likely to be less than 10% and, thus, immediate chest reopening should be performed. (This is a Class-IIa recommendation using ILCOR guideline recommendations.)
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References
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- Dunning J, Prendergast B, Mackway-Jones K. Towards evidence-based medicine in cardiothoracic surgery: best BETS. Interact Cardiovasc Thorac Surg 2003;405–409.
- Handley AJ, Koster R, Monsieurs K, Perkins GD, Davies S, Bossaert L. European Resuscitation Council Guidelines for Resuscitation 2005: Section 2: adult basic life support and use of automated external defibrillators. Resuscitation 2005; 67S1:S7–23.
- Deakin CD, Nolan JP. European Resuscitation Council Guidelines for Resuscitation 2005: Section 3: Electrical therapies: automated external defibrillators, defibrillation, cardioversion and pacing. Resuscitation 2005; 67S1:S25–37.
- Szili-Torok T, Theuns D, Verblaauw T, Scholten M, Kimman GJ, Res J, Jordaens L. Transthoracic defibrillation of short-lasting ventricular fibrillation: a randomised trial for comparison of the efficacy of low-energy biphasic rectilinear and monophasic damped sine shocks. Acta Cardiologica 2002; 57:329–334.[CrossRef][Medline]
- Higgins SL, O'Grady SG, Banville I, Chapman FW, Schmitt PW, Lank P, Walker R, Ilina M. Efficacy of lower-energy biphasic shocks for transthoracic defibrillation: a follow-up clinical study. Prehospital Emergency Care 2004; 8:262–267.[CrossRef][Medline]
- Steill IG, Walker RG, Nesbitt LP, Chapman FW, Cousineau D, Christenson J, Bradford P, Sookram S, Berringer R, Lank P, Wells GA. BIPHASIC Trial: a randomised comparison of fixed lower versus escalating higher energy levels for defibrillation in out-of-hospital cardiac arrest. Circulation 2007; 115:1511–1517.[Abstract/Free Full Text]
- Martens PR, Russell JK, Wolcke B, Paschen H, Kuisma M, Gliner BE, Weaver WD, Bossaert L, Chamberlain D, Schneider T. Optimal response to cardiac arrest study: defibrillation waveform effects. Resuscitation 2001; 49:233–243.[CrossRef][Medline]
- Morrison LJ, Dorian P, Long J, Vermeulen M, Schwartz B, Sawadsky B, Frank J, Cameron B, Burgess R, Shield J, Bagley P, Mausz V, Brewer JE, Lerman BB. Out-of-hospital cardiac arrest rectilinear biphasic to monophasic damped sine defibrillation waveforms with advanced life support intervention trial (ORBIT). Resuscitation 2005; 66:149–157.[CrossRef][Medline]
- Schwartz B, Bowdle A, Jett K, Mair P, Lindner KH, Aldea GS, Lazzara RG, O'Grady SG, Schmitt PW, Walker RG, Chapman FW, Tacker WA. Biphasic shocks compared with monophasic damped sine wave shocks for direct ventricular defibrillation during open-heart surgery. Anesthesiology 2003; 98:1063–1069.[CrossRef][Medline]
- Edelson DP, Abella BS, Kramer-Johansen J, Wik L, Myklebust H, Barry AM, Merchant RM, Vanden Hoek TL, Steen PA, Becker LB. Effects of compression depth and pre-shock pause predict defibrillation failure during cardiac arrest. Resuscitation 2006; 71:137–145.[CrossRef][Medline]
- van Alem AP, Chapman FW, Lank P, Hart AAM, Koster RW. A prospective randomised and blinded comparison of first shock success of monophasic and bisphasic waveforms in out-of-hospital cardiac arrest. Resuscitation 2003; 58:17–24.[CrossRef][Medline]
- Carpenter J, Rea TD, Murray JA, Kudenchuk PJ, Eisenberg MS. Defibrillation waveform and post-shock rhythm in out-of-hospital ventricular fibrillation cardiac arrest. Resuscitation 2003; 59:189–196.[CrossRef][Medline]
- Cammarata G, Weil MH, Csapoczi P, Sun S, Tang W. Challenging the rationale of three sequential shocks for defibrillation. Resuscitation 2006; 69:23–27.[CrossRef][Medline]
- Nieman JT, Burian D, Garner D, Lewis RJ. Monophasic versus biphasic transthoracic countershock after prolonged ventricular fibrillation in a swine model. J Am Coll Cardiol 2000; 36:932–938.[Abstract/Free Full Text]
- Schneider T, Martens PR, Paschen H, Kuisma M, Wolcke B, Gliner BE, Russell JK, Weaver WD, Bossaert L, Chamberlain D. Multicentre, randomised controlled trial of 150J biphasic shocks compared with 200- to 360J monophasic shocks in the resuscitation of out-of-hospital cardiac arrest victims. Circulation 2000; 102:1780–1787.[Abstract/Free Full Text]
- Gliner BE, Jorgenson DB, Poole JE, White RD, Kanz KG, Lyster TD, Leyde KW, Powers DJ, Morgan CB, Kronmal RA, Bardy GH. Treatment of out-of-hospital cardiac arrest with a low-energy impedance-compensating biphasic waveform automatic external defibrillator. Biochemical Instrumentation and Technology 1998; 32:631–644.
- Bardy GH, Marchlinski FE, Sharma AD, Worley SJ, Luceri RM, Yee R, Halperin BD, Fellows CL, Ahern TS, Chilson DA, Packer DL, Wilber DJ, Mattioni A, Reddy R, Kronmal RA, Lazzara R. Multicenter comparison of truncated biphasic shocks and standard damped sine wave monophasic shocks for transthoracic ventricular defibrillation. Circulation 1996; 94:2507–2514.[Abstract/Free Full Text]
- White R, Blackwell TH, Russell JK, Synder DE, Jorgenson DB. Transthoracic impedance does not affect defibrillation, resuscitation or survival in patients with out-of-hospital cardiac arrest treated with a non-escalating biphasic waveform defibrillator. Resuscitation 2005; 64:63–69.[CrossRef][Medline]
- Mackay JH, Powell SJ, Osgathorp J, Rozario CJ. Six-year prospective audit of chest reopening after cardiac arrest. Eur J Cardiothorac Surg 2002; 22:421–425.[Abstract/Free Full Text]
- Morley PT, Zaritsky A. The evidence evaluation process for the 2005 International Consensus Conference on cardiopulmonary resuscitation and emergency cardiovascular care science with treatment recommendations. Resuscitation 2005; 67:167–170.[CrossRef][Medline]
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Top
Abstract
1. Introduction