Cheskes Sheldon, Dorian Paul, Feldman Michael, McLeod Shelley, Scales Damon C, Pinto Ruxandra, Turner Linda, Morrison Laurie J, Drennan Ian R, Verbeek P Richard
Sunnybrook Centre for Prehospital Medicine, Toronto, Ontario, Canada; Department of Family and Community Medicine, Division of Emergency Medicine, University of Toronto, Toronto, Ontario, Canada; Li Ka Shing Knowledge Institute, St. Michaels Hospital, Toronto, Ontario, Canada.
St. Michaels Hospital, Toronto, Ontario, Canada.
Resuscitation. 2020 May;150:178-184. doi: 10.1016/j.resuscitation.2020.02.010. Epub 2020 Feb 19.
The primary objective was to determine the feasibility and safety of a cluster randomized controlled trial (RCT) with crossover comparing vector change defibrillation (VC) or double sequential external defibrillation (DSED) to standard defibrillation for patients experiencing refractory ventricular fibrillation (VF). Secondary objectives were to assess the rates of VF termination (VFT) and return of spontaneous circulation (ROSC).
We conducted a pilot cluster RCT with crossover in four Canadian paramedic services including all treated adult OHCA patients who presented in VF and received a minimum of three successive defibrillation attempts. Each EMS service was randomly assigned to provide standard defibrillation, VC or DSED. Agencies crossed over to an alternate defibrillation strategy after six months.
152 patients were enrolled. With respect to feasibility, 89.5% of cases received the defibrillation strategy they were randomly allocated to, and 93.1% of cases received a VC or DSED shock prior to the sixth defibrillation attempt. There were no safety concerns reported. In the standard group, 66.6% of cases resulted in VFT, compared to 82.0% in VC and 76.3% in the DSED group. ROSC was achieved in 25.0%, 39.3% and 40.0% of standard, VC and DSED groups, respectively.
Our findings suggest the DOSE-VF protocol is feasible and safe. Rates of VFT and ROSC were higher in the VC and DSED than standard defibrillation. The results of this pilot trial will allow us to inform a multicenter cluster RCT with crossover to determine if alternate defibrillation strategies for refractory VF may impact clinical outcomes.
主要目的是确定一项交叉设计的整群随机对照试验（RCT）的可行性和安全性，该试验将向量改变除颤（VC）或双序列体外除颤（DSED）与标准除颤用于难治性室颤（VF）患者进行比较。次要目的是评估室颤终止（VFT）率和自主循环恢复（ROSC）率。
我们在加拿大的四个护理急救服务机构进行了一项交叉设计的试点整群RCT，纳入所有出现室颤且至少接受三次连续除颤尝试的成年院外心脏骤停（OHCA）患者。每个急救服务机构被随机分配提供标准除颤、VC或DSED。各机构在六个月后交叉采用另一种除颤策略。
共纳入152例患者。在可行性方面，89.5%的病例接受了随机分配的除颤策略，93.1%的病例在第六次除颤尝试前接受了VC或DSED电击。未报告安全问题。标准组中66.6%的病例实现了VFT，而VC组为82.0%，DSED组为76.3%。标准组、VC组和DSED组的ROSC率分别为25.0%、39.3%和40.0%。
我们的研究结果表明DOSE-VF方案是可行且安全的。VC和DSED组的VFT和ROSC率高于标准除颤组。这项试点试验的结果将使我们能够为一项交叉设计的多中心整群RCT提供信息，以确定难治性VF的替代除颤策略是否可能影响临床结局。
