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ALS-11-v1

1 RECOVER 2.0 Worksheet

2 QUESTION ID: ALS-11

3 PICO Question:
In cats and dogs with CPA due to a shockable rhythm (P) does the use of a monophasic defibrillator (I) compared to a biphasic defibrillator (C) improve outcome (O)?

4 Outcomes:
Favorable neurologic outcome,Surrogate marker(s) of perfusion,Survival to Discharge,ROSC

5 Prioritized Outcomes (1= most critical; final number = least important):

6 Favorable neurologic outcome
7 Survival to discharge
8 ROSC
9 Surrogate markers of perfusion

10 Domain chairs: Gareth Buckley, Elizabeth Rozanski, Jake Wolf

11 Evidence evaluators: Jeannette Cremer, Christina Maglaras

12 Conflicts of interest: None

13 Search strategy: See attached document

14 Evidence Review:

15 Study Design		16 Reduced Quality Factors 17 0 = no serious, - = serious, 18 - - = very serious				19 Positive Quality Factors 20 0 = none, + = one, ++ = multiple			21 Dichotomous Outcome Summary			22 Non-Dichotomous Outcome Summary 23 Brief description	24 Overall Quality 25 High, moderate, low, very low, none
26 No of studies	27 Study Type	28 RoB	29 Indirectness	30 Imprecision	31 Inconsistency	32 Large Effect	33 Dose-Response	34 Confounder	35 # Intervention with Outcome	36 # Control with Outcome	37 RR (95% CI)
38 Outcome: Favorable neurologic outcome
39 2	40 CT	41 0	42 -	43 0	44 -							45 Slight benefit for biphasic	46 Low
47 1	48 OS	49 -	50 -	51 0	52 0							53 Biphasic with improved CPC	54 Very low
55 0	56 ES
57 Outcome: Survival to discharge
58 3	59 CT	60 0	61 -	62 -	63 -	64 +						65 Slight benefit for biphasic	66 Moderate
67 1	68 OS	69 -	70 -	71 0	72 0	73 +						74 Biphasic with improved survival	75 High
76 2	77 ES	78 0	79 -	80 -	81 -							82 No difference	83 Low
84 Outcome: ROSC
85 5	86 CT	87 0	88 -	89 -	90 -							91 Slight benefit for biphasic	92 Moderate
93 1	94 OS	95 -	96 -	97 0	98 0							99 Biphasic with improved ROSC	100 High
101 9	102 ES	103 -	104 -	105 -	106 -							107 Slight benefit with BP	108 Low
109 Outcome: Surrogate markers of perfusion
110 0	111 CT
112 0	113 OS
114 6	115 ES	116 -	117 -	118 -	119 0	120 0							121 Very low

122 PICO Question Summary

123 Introduction

124 In patients with VF or pVT, successful defibrillation is necessary to achieve ROSC. The most common defibrillation waveforms in use are biphasic (BP) and monophasic (MP). In MP defibrillation, a high-energy unidirectional current is used, whereas BP defibrillation allows for lower-energy, bidirectional currents. Current veterinary and human guidelines recommend BP defibrillation when available over MP defibrillation because higher energy defibrillation has been associated with greater myocardial and other tissue injury.1–3

125 Consensus on science

126 Outcome 1: Favorable neurologic outcome

127 For the most critical outcome of favorable neurologic outcome, two clinical trials (very low quality of evidence, downgraded for very serious indirectness and serious inconsistency), and one observational study (very low quality of evidence, downgraded for serious risk of bias and serious indirectness) were identified. A multi-center randomized, controlled trial of adults with out-of-hospital cardiac arrest demonstrated a higher percentage of patients with good cerebral performance category at the time of discharge (87% vs 53%, P=0.03) with BP therapy.4 Another clinical trial in adults with non-traumatic out-of-hospital cardiac arrest with VF were randomly allocated to receive either MP or BP defibrillation.5 No difference in neurologic outcome was noted between groups. An observational study of all adults with out-of-hospital cardiac arrest in Japan between 2005-2014 found improved neurologic outcome with BP defibrillation compared to MP defibrillation.6

128 Outcome 2: Survival to discharge

129 Four clinical trials (the 2 mentioned above and two additional trials) in adults with out-of-hospital cardiac arrest evaluated survival to discharge between BP and MP defibrillation (very low quality of evidence, downgraded for very serious indirectness and serious inconsistency). The 2 previously mentioned studies showed no improvement in survival to discharge4,5 Similarly, the 2 additional clinical trials showed no benefit of BP over MP for this outcome.7,8 However, in the subset of patients in whom CPA was witnessed and when defibrillation was administered within 4-10 minutes in one study, improved survival was noted with BP defibrillation compared to MP defibrillation (BP 45% vs 31%, P=0.0002).7 In addition, 1 observational study demonstrated improved survival to 1 month with BP compared to MP defibrillation.6 Finally, 1 experimental swine study showed no difference in survival between BP and MP defibrillation in a prolonged VF model left untreated for the first 10 minutes.9

130 Outcome 3: ROSC

131 Five clinical trials in people (very low quality of evidence, downgraded for very serious indirectness and serious inconsistency) evaluated this outcome. Three of the 5 OOH studies showed no improvement in frequency of ROSC with BP defibrillation compared to MP.5,7,10 Of the remaining 2 trials, one examined OOH CPA and one IH CPA, and both demonstrated significantly greater frequency of ROSC in patients treated with BP vs those treated with MP defibrillation.4,8 In one, a BP defibrillator was compared to two MP defibrillators, and ROSC frequency was higher with the BP (76%) than the MP (54%, P=0.024).8 In the other, 76% of patients were successfully defibrillated with BP vs 54% with MP (P=0.01).4 In addition, the previously described observational study showed higher frequency of ROSC with BP than MP.6 Nine experimental studies (4 in pigs and 5 in dogs) compared BP and MP defibrillation in various arrest models (very low quality of evidence, downgraded for serious risk of bias, serious indirectness, serious imprecision, and serious inconsistency). Overall, 5 studies showed no benefit of BP over MP in frequency of ROSC.9,11–13 Of the 4 remaining studies that showed a benefit of BP over MP, 3 were canine studies.14–17

132 Outcome 4: Surrogate markers of perfusion

133 Six experimental studies in dogs and pigs evaluated this outcome (very low quality of evidence, downgraded for serious risk of bias, serious indirectness, and serious imprecision). Most identified less myocardial dysfunction, lower energy requirements, shorter periods of CPR, and lower values for markers of cardiac injury with BP therapy.9,11,12,18,19 One study in ten toy breed dogs found more severe ECG abnormalities, more persistently elevated cardiac biomarkers, and severely depressed left ventricular cardiac performance in the MP group compared to the BP group.15 However, all dogs included in the study survived.

134 Treatment recommendation

135 We recommend using a biphasic defibrillator over a monophasic defibrillator in dogs and cats with shockable rhythms (strong recommendation, very low quality of evidence).

136 Justification of treatment recommendation

137 Multiple studies show improved neurologic outcome, survival to discharge, and ROSC with BP defibrillation compared to MP defibrillation. Many experimental studies in pigs and dogs show improved hemodynamics and decreased myocardial injury with BP defibrillation.

138 Knowledge gaps

139 While studies in people and experimental studies in pigs and dogs support the use of BP defibrillators over MP defibrillators, no clinical studies in dogs and no studies in cats have been performed. The effects of MP versus BP defibrillation waveform on outcome during CPR in dogs and cats with shockable rhythms is considered a low priority knowledge gap.

140 References:

141 1. Xie J, Weil MH, Sun S, et al. High-Energy Defibrillation Increases the Severity of Postresuscitation Myocardial Dysfunction. Circulation. 1997;96(2):683-688.

142 2. Panchal AR, Bartos JA, Cabañas JG, et al. Part 3: Adult Basic and Advanced Life Support: 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation. 2020;142(16_suppl_2):S366-S468.

143 3. Fletcher DJ, Boller M, Brainard BM, et al. RECOVER evidence and knowledge gap analysis on veterinary CPR. Part 7: Clinical guidelines: RECOVER clinical guidelines. J Vet Emerg Crit Care. 2012;22(s1):S102-S131.

144 4. Schneider T, Martens PR, Paschen H, et al. Multicenter, randomized, controlled trial of 150-J biphasic shocks compared with 200- to 360-J monophasic shocks in the resuscitation of out-of-hospital cardiac arrest victims. Optimized Response to Cardiac Arrest (ORCA) Investigators. Circulation. 2000;102(15):1780-1787.

145 5. Kudenchuk PJ, Cobb LA, Copass MK, et al. Transthoracic incremental monophasic versus biphasic defibrillation by emergency responders (TIMBER): a randomized comparison of monophasic with biphasic waveform ascending energy defibrillation for the resuscitation of out-of-hospital cardiac arrest due. Circulation. 2006;114(19):2010-2018.

146 6. Hagihara A, Onozuka D, Ono J, Nagata T, Hasegawa M. Interaction of defibrillation waveform with the time to defibrillation or the number of defibrillation attempts on survival from out-of-hospital cardiac arrest. Resuscitation. 2018;122:54-60.

147 7. Morrison LJ, Dorian P, Long J, et al. Out-of-hospital cardiac arrest rectilinear biphasic to monophasic damped sine defibrillation waveforms with advanced life support intervention trial (ORBIT). Resuscitation. 2005;66(2):149-157.

148 8. Martens PR, Russell JK, Wolcke B, et al. Optimal Response to Cardiac Arrest study: defibrillation waveform effects. Resuscitation. 2001;49(3):233-243.

149 9. Tang W, Weil MH, Sun S, et al. A comparison of biphasic and monophasic waveform defibrillation after prolonged ventricular fibrillation. Chest. 2001;120(3):948-954.

150 10. van Alem AP, Chapman FW, Lank P, Hart AAM, Koster RW. A prospective, randomised and blinded comparison of first shock success of monophasic and biphasic waveforms in out-of-hospital cardiac arrest. Resuscitation. 2003;58(1):17-24.

151 11. Tang W, Weil MH, Sun S, et al. The effects of biphasic and conventional monophasic defibrillation on postresuscitation myocardial function. J Am Coll Cardiol. 1999;34(3):815-822.

152 12. Leng CT, Paradis NA, Calkins H, et al. Resuscitation after prolonged ventricular fibrillation with use of monophasic and biphasic waveform pulses for external defibrillation. Circulation. 2000;101(25):2968-2974.

153 13. Scott BD, Kallok MJ, Birkett C, Kieso RA, Kerber RE. Transthoracic defibrillation: effect of dual-pathway sequential pulse shocks and single-pathway biphasic pulse shocks in a canine model. Am Heart J. 1993;125(1):99-109.

154 14. Clark CB, Zhang Y, Davies LR, Karlsson G, Kerber RE. Transthoracic biphasic waveform defibrillation at very high and very low energies: a comparison with monophasic waveforms in an animal model of ventricular fibrillation. Resuscitation. 2002;54(2):183-186.

155 15. Lee SG, Moon HS, Hyun C. The efficacy and safety of external biphasic defibrillation in toy breed dogs. J Vet Emerg Crit Care. 2008;18(4):362-369.

156 16. Clark CB, Zhang Y, Davies LR, Karlsson G, Kerber RE. Pediatric transthoracic defibrillation: biphasic versus monophasic waveforms in an experimental model. Resuscitation. 2001;51(2):159-163.

157 17. Flaker GC, Schuder JC, McDaniel WC, Stoeckle H, Dbeis M. Superiority of biphasic shocks in the defibrillation of dogs by epicardial patches and catheter electrodes. Am Heart J. 1989;118(2):288-291.

158 18. Tang W, Weil MH, Sun S, et al. The effects of biphasic waveform design on post-resuscitation myocardial function. J Am Coll Cardiol. 2004;43(7):1228-1235.

159 19. Osswald S, Trouton TG, O’Nunain SS, et al. Relation between shock-related myocardial injury and defibrillation efficacy of monophasic and biphasic shocks in a canine model. Circulation. 1994;90(5):2501-2509.

160 Supplemental:

161 Outcome: Favorable neurologic outcome

162 2 Clinical Trials

163 Kudenchuk et al., 2006: Transthoracic incremental monophasic versus biphasic defibrillation by emergency responders

164 ● Adults with non-traumatic OOH VF were randomly allocated to monophasic or biphasic waveforms

165 ● No difference in presence of VF or organized rhythm, survival to discharge, or neuro outcome

166 Schneider et al., 2000: Multicenter, randomized, controlled trial of 150 J biphasic shocks compared with 200 to 360 J monophasic shocks in the resuscitation of OOHCA victims

167 ● AEDs randomized according to waveform on daily basis in 4 EDs

168 ● Higher ROSC with biphasic and good neuro outcome, but no difference in survival

169 1 Observational Studies

170 Hagihara et al., 2018: Interaction of defibrillation waveform with the time to defibrillation or the number of defibrillation attempts on survival from OOHCA

171 ● Evaluation of all OOHCA in Japan from 2005-2014

172 ● Improved ROSC, 1 month survival and CPC score with biphasic compared to monophasic

173 0 Experimental Studies

174 Outcome: Survival to discharge

175 4 Clinical Trials

176 Schneider et al., 2000: Multicenter, randomized, controlled trial of 150 J biphasic shocks compared with 200 to 360 J monophasic shocks in the resuscitation of OOHCA victims

177 ● AEDs randomized according to waveform on daily basis in 4 EDs

178 ● Higher ROSC with biphasic and good neuro outcome, but no difference in survival

179 Morrison et al., 2005: OOHCA rectilinear biphasic to monophasic damped sine defibrillation waveforms with ALS intervention trial (ORBIT)

180 ● OHCA requiring at least one shock treated by ALS paramedics

181 ● No difference in ROSC, survival to discharge. However, within 4-10 minutes of bystander witnessed, improved survival with biphasic

182 Martens et al., 2001: Optimal response to cardiac arrest study: defibrillation waveforms effects

183 ● AEDs randomized according to waveform on daily basis in 4 EDs for adults with VF and cardiac etiology

184 ● No difference in refibrillation, survival to admission or discharge. Improved ROSC pre-hospital with biphasic compared to one form of monophasic

185 1 Observational Studies

186 Hagihara et al., 2018: Interaction of defibrillation waveform with the time to defibrillation or the number of defibrillation attempts on survival from OOHCA

187 ● Evaluation of all OOHCA in Japan from 2005-2014

188 ● Improved ROSC, 1 month survival and CPC score with biphasic compared to monophasic

189 1 Experimental Studies

190 Tang et al., 2001: A comparison of biphasic and monophasic waveform defibrillation after prolonged VF

191 ● VF induced in 20 pigs. Untreated VF for 10 minutes and then randomized with 3 150 J biphasic shocks or 200-300-360 J monophasic shocks

192 ● No difference in ROSC or survival. Less impaired myocardial function post-resuscitation with biphasic

193 Tang et al., 2004: The effects of biphasic waveform design on post-resuscitation myocardial function

194 ● Randomized 4 groups of pigs with 7 minutes of electrically induced VF. Randomized to low energy biphasic truncated defibrillation at 150 or 200 J or high energy biphasic at 200 or 360 J

195 ● No difference in survival or neuro alertness score amongst four groups. Lower ROSC with BTEH 200 J

196 ● Animals with BTEL required fewer shocks, less CPR, and less energy. Myocardial function (CO, SV, EF, MAP) best for lower energy

197 Outcome: ROSC

198 5 Clinical Trials

199 Kudenchuk et al., 2006: Transthoracic incremental monophasic versus biphasic defibrillation by emergency responders

200 ● Adults with non-traumatic OOH VF were randomly allocated to monophasic or biphasic waveforms

201 ● No difference in presence of VF or organized rhythm, survival to discharge, or neuro outcome.

202 Schneider et al., 2000: Multicenter, randomized, controlled trial of 150 J biphasic shocks compared with 200 to 360 J monophasic shocks in the resuscitation of OOHCA victims

203 ● AEDs randomized according to waveform on daily basis in 4 EDs

204 ● Higher ROSC with biphasic and good neuro outcome, but no difference in survival

205 Morrison et al., 2005: OOHCA rectilinear biphasic to monophasic damped sine defibrillation waveforms with ALS intervention trial (ORBIT)

206 ● OHCA requiring at least one shock treated by ALS paramedics

207 ● No difference in ROSC, survival to discharge. However, within 4-10 minutes of bystander witnessed, improved survival with biphasic

208 ● Higher success in conversion to organized rhythm with first shock in BP (increased probability by 57%)

209 Martens et al., 2001: Optimal response to cardiac arrest study: defibrillation waveforms effects

210 ● AEDs randomized according to waveform on daily basis in 4 EDs for adults with VF and cardiac etiology

211 ● No difference in refibrillation, survival to admission or discharge. Improved ROSC pre-hospital with biphasic compared to one form of monophasic

212 van Alem et al., 2003: A prospective, randomised and blinded comparison of first shock success of monophasic and biphasic waveforms in OOHCA

213 ● Compared AEDs with monophasic and biphasic waveforms in adults with OOHCA (both received an initial shock of 200 J)

214 ● Higher first success rate of conversion to an organized rhythm for BP. No difference in termination of VF at 5 seconds, survival, or ROSC

215 1 Observational Studies

216 Hagihara et al., 2018: Interaction of defibrillation waveform with the time to defibrillation or the number of defibrillation attempts on survival from OOHCA

217 ● Evaluation of all OOHCA in Japan from 2005-2014

218 ● Improved ROSC, 1 month survival and CPC score with biphasic compared to monophasic

219 11 Experimental Studies

220 Tang et al., 2001: A comparison of biphasic and monophasic waveform defibrillation after prolonged VF

221 ● VF induced in 20 pigs. Untreated VF for 10 minutes and then randomized with 3 150 J biphasic shocks or 200-300-360 J monophasic shocks

222 ● No difference in ROSC or survival.

223 Tang et al., 1999: The effects of biphasic and conventional monophasic defibrillation on postresuscitation myocardial function

224 ● 20 pigs with induced VF with either 4 or 7 minutes of untreated VF randomized to three 150 J biphasic shocks or escalating monophasic shocks

225 ● Biphasic associated with less myocardial dysfunction compared to escalating monophasic. No difference in ROSC

226 Tang et al., 2004: The effects of biphasic waveform design on post-resuscitation myocardial function

227 ● Randomized 4 groups of pigs with 7 minutes of electrically induced VF. Randomized to low energy biphasic truncated defibrillation at 150 or 200 J or high energy biphasic at 200 or 360 J

228 ● No difference in survival or neuro alertness score amongst four groups. Lower ROSC with BTEH 200 J

229 Clark et al., 2002: Transthoracic biphasic waveform defibrillation at very high and very low energies: a comparison with monophasic waveforms in an animal model of VF

230 ● 13 swine with electrically induced VF that received monophasic and biphasic shocks in random order

231 ● Successful defibrillation increased with increasing energy. Biphasic superior at lower energy; no significant difference at higher energy levels

232 Lee et al., 2008: The efficacy and safety of external biphasic defibrillation in toy breed dogs

233 ● Evaluated 10 toy breed dogs with BP versus MP

234 ● BP required 30% less shock energy and was more effective at converting at all time points than MP. All dogs survived

235 Niemann et al., 2000: Monophasic versus biphasic transthoracic countershock after prolonged VF in a swine model

236 ● Swine randomized to receive either monophasic truncated exponential shocks or low-energy (150 J) monophasic shocks

237 ● No difference in ROSC, CPR time, or hemodynamic variables

238 Leng et al., 2000: Resuscitation after prolonged VF with use of monophasic and biphasic waveform pulses for external defibrillation

239 ● Randomized 26 dogs to monophasic or biphasic waveforms with induced VF

240 ● Less myocardial dysfunction with biphasic. Shorter resuscitation times for biphasic with prolonged CPA, but no difference in ROSC

241 Zhang et al., 2003: Open-chest epicardial surgical defibrillation

242 ● 28 pigs with induced VF randomized to monophasic or biphasic epicardial, open chest defibrillation

243 ● With small surgical paddles, greater shock success rate with BP. No difference with large paddles

244 Clark et al., 2001: Pediatric transthoracic defibrillation: biphasic versus monophasic waveforms in an experimental model

245 ● 27 piglets with induced VF and administered BP and MP shocks

246 ● BP had better termination of VF than MP

247 Flaker et al., 1989: Superiority of biphasic shocks in the defibrillation of dogs by epicardial patches and catheter electrodes

248 ● Patches implanted on LV and RV of 28 dogs with induced VF and 7 dogs with transvenous catheter with electrodes. Administered BP and MP shocks

249 ● BP superior at some energy levels for patches; with the catheter electrodes, BP universally more effective at terminating rhythm and ROSC

250 Scott et al., 1993: Transthoracic defibrillation: effect of dual-pathway sequential pulse shocks and single-pathway biphasic pulse shocks in a canine model

251 ● Three groups of dogs administered shocks of variable duration, voltage, and polarity for MP and BP

252 ● No difference between them at any level

253 Outcome: Surrogate markers of perfusion

254 0 Clinical Trials

255 0 Observational Studies

256 6 Experimental Studies

257 Tang et al., 2001: A comparison of biphasic and monophasic waveform defibrillation after prolonged VF

258 ● VF induced in 20 pigs. Untreated VF for 10 minutes and then randomized with 3 150 J biphasic shocks or 200-300-360 J monophasic shocks

259 ● No difference in ROSC or survival. Less impaired myocardial function post-resuscitation with biphasic

260 Niemann et al., 2000: Monophasic versus biphasic transthoracic countershock after prolonged VF in a swine model

261 ● Swine randomized to receive either monophasic truncated exponential shocks or low-energy (150 J) monophasic shocks

262 ● No difference in ROSC, CPR time, or hemodynamic variables

263 Tang et al., 1999: The effects of biphasic and conventional monophasic defibrillation on postresuscitation myocardial function

264 ● 20 pigs with induced VF with either 4 or 7 minutes of untreated VF randomized to three 150 J biphasic shocks or escalating monophasic shocks

265 ● Biphasic associated with less myocardial dysfunction compared to escalating monophasic

266 Tang et al., 2004: The effects of biphasic waveform design on post-resuscitation myocardial function

267 ● Randomized 4 groups of pigs with 7 minutes of electrically induced VF. Randomized to low energy biphasic truncated defibrillation at 150 or 200 J or high energy biphasic at 200 or 360 J

268 ● Animals with BTEL required fewer shocks, less CPR, and less energy. Myocardial function (CO, SV, EF, MAP) best for lower energy

269 Leng et al., 2000: Resuscitation after prolonged VF with use of monophasic and biphasic waveform pulses for external defibrillation

270 ● Randomized 26 dogs to monophasic or biphasic waveforms with induced VF

271 ● Less myocardial dysfunction with biphasic. Shorter resuscitation times for biphasic with prolonged CPA

272 Lee et al., 2008: The efficacy and safety of external biphasic defibrillation in toy breed dogs

273 ● Evaluated 10 toy breed dogs with BP versus MP

274 ● BP required 30% less shock energy, cardiac biomarkers elevated and sustained for longer periods in MP group and ECG changes more severe and longer in MP group. LV cardiac performance severely depressed in MP group

275 Osswald et al., 1994: Relation between shock related myocardial injury and defibrillation efficacy of monophasic and biphasic shocks in a canine model

276 ● Different waveforms tested in 12 dogs using implantable devices

277 ● BP associated with less injurious effects on myocardial oxidative metabolism and hemodynamic performance

DMU Timestamp: July 13, 2023 21:18