J T Niemann1, B Cruz, D Garner, R J Lewis. 1. Department of Emergency Medicine, University of California-Los Angeles School of Medicine, Harbor-UCLA Medical Center, Torrance, CA, USA. mann@emedharbor.edu
Abstract
STUDY OBJECTIVE: Prior laboratory and clinical studies demonstrate that cardiopulmonary resuscitation (CPR) preceding countershock of prolonged ventricular fibrillation (VF) increases the likelihood of successful cardiac resuscitation. The lower limit of VF duration at which time preshock CPR provides no benefit has not been specifically studied. The purpose of this study was to compare countershock and cardiac resuscitation outcome between immediate countershock of VF of 5-minute duration and CPR without drug therapy before countershock in a swine model. METHODS: VF was induced in anesthetized and instrumented swine. After 5 minutes of VF, animals received 1 of 2 treatments. Animals in group 1, a "historical" control group (n=20), received immediate countershock followed by CPR and repeated shocks if needed. Group 2 animals (n=11) received CPR for 90 seconds preceding countershock, then continued CPR and repeated countershock if necessary. Drugs were not administered to either group, and resuscitation efforts were discontinued if a perfusing rhythm was not restored within 10 minutes of the first countershock. First shock success rate (defined as termination of VF), the number of shocks required to terminate VF, and the cardiac resuscitation rate were compared between groups. RESULTS: The first shock terminated VF in 13 of 20 group 1 animals and 2 of 11 group 2 animals (P =.023). All but 1 animal in group 1 developed pulseless electrical activity after countershock. All but 1 animal in group 1 were eventually successfully resuscitated with CPR and repeated shocks if necessary. Four group 2 animals could not be resuscitated (P =.042). CONCLUSION: Although effective in improving outcome of prolonged VF, CPR preceding countershock of VF of 5-minute duration does not improve the response to the first shock, decrease the incidence of postshock pulseless electrical activity, or the rate of return of circulation. In this study, CPR preceding countershock resulted in a significantly lower cardiac resuscitation rate.
STUDY OBJECTIVE: Prior laboratory and clinical studies demonstrate that cardiopulmonary resuscitation (CPR) preceding countershock of prolonged ventricular fibrillation (VF) increases the likelihood of successful cardiac resuscitation. The lower limit of VF duration at which time preshock CPR provides no benefit has not been specifically studied. The purpose of this study was to compare countershock and cardiac resuscitation outcome between immediate countershock of VF of 5-minute duration and CPR without drug therapy before countershock in a swine model. METHODS:VF was induced in anesthetized and instrumented swine. After 5 minutes of VF, animals received 1 of 2 treatments. Animals in group 1, a "historical" control group (n=20), received immediate countershock followed by CPR and repeated shocks if needed. Group 2 animals (n=11) received CPR for 90 seconds preceding countershock, then continued CPR and repeated countershock if necessary. Drugs were not administered to either group, and resuscitation efforts were discontinued if a perfusing rhythm was not restored within 10 minutes of the first countershock. First shock success rate (defined as termination of VF), the number of shocks required to terminate VF, and the cardiac resuscitation rate were compared between groups. RESULTS: The first shock terminated VF in 13 of 20 group 1 animals and 2 of 11 group 2 animals (P =.023). All but 1 animal in group 1 developed pulseless electrical activity after countershock. All but 1 animal in group 1 were eventually successfully resuscitated with CPR and repeated shocks if necessary. Four group 2 animals could not be resuscitated (P =.042). CONCLUSION: Although effective in improving outcome of prolonged VF, CPR preceding countershock of VF of 5-minute duration does not improve the response to the first shock, decrease the incidence of postshock pulseless electrical activity, or the rate of return of circulation. In this study, CPR preceding countershock resulted in a significantly lower cardiac resuscitation rate.
Authors: Ian G Stiell; Clif Callaway; Dan Davis; Tom Terndrup; Judy Powell; Andrea Cook; Peter J Kudenchuk; Mohamud Daya; Richard Kerber; Ahamed Idris; Laurie J Morrison; Tom Aufderheide Journal: Resuscitation Date: 2008-05-19 Impact factor: 5.262
Authors: Ian G Stiell; Graham Nichol; Brian G Leroux; Thomas D Rea; Joseph P Ornato; Judy Powell; James Christenson; Clifton W Callaway; Peter J Kudenchuk; Tom P Aufderheide; Ahamed H Idris; Mohamud R Daya; Henry E Wang; Laurie J Morrison; Daniel Davis; Douglas Andrusiek; Shannon Stephens; Sheldon Cheskes; Robert H Schmicker; Ray Fowler; Christian Vaillancourt; David Hostler; Dana Zive; Ronald G Pirrallo; Gary M Vilke; George Sopko; Myron Weisfeldt Journal: N Engl J Med Date: 2011-09-01 Impact factor: 91.245
Authors: Jon C Rittenberger; Brian Suffoletto; David Salcido; Eric Logue; James J Menegazzi Journal: Resuscitation Date: 2008-07-11 Impact factor: 5.262
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