Stotz Martin, Albrecht Roland, Zwicker Gallus, Drewe Juergen, Ummenhofer Wolfgang
Department of Anesthesiology, University Hospital of Basel, CH-4031 Basel, Switzerland.
Resuscitation. 2003 Sep;58(3):277-82. doi: 10.1016/s0300-9572(03)00271-5.
Early defibrillation using automated external defibrillators (AEDs) has been advocated to improve survival in witnessed out-of-hospital cardiac arrest (OHCA) due to pulseless ventricular tachycardia (VT) and ventricular fibrillation (VF). However, when VT/VF is untreated and prolonged for more than a few minutes, defibrillation using AEDs may fail.
This retrospective study reviewed the charts from local emergency medical service (EMS) between the years 1993 to 2001 to evaluate the value of the AED after its introduction into our EMS. All witnessed OHCA due to VT/VF were analysed; cases of collapse witnessed by EMS were excluded. The primary endpoint was defined as survival to hospital discharge and at 1-year follow-up, and the secondary endpoint as survival without major neurological deficit. A total of 76 patients were treated for witnessed VT/VF before the implementation of the AED and 92 patients after its implementation.
Before the introduction of paramedic AED defibrillation, physician defibrillation was performed at 15.6 min (+/-5.5, S.D.). After the introduction of AED defibrillation, paramedic defibrillation was performed at 5.7 min (+/-2.4, S.D.); the mean response interval from the call to defibrillation was shortened significantly (P<0.001). At the same time, survival to hospital discharge decreased from 23.7% (18/76 patients) to 14.1% (13/92) (P=0.112) and at 1-year follow-up from 17.1% (13/76) to 9.8% (9/92) (P=0.161). Favourable neurological outcome at 1-year follow-up also decreased from 14.5% (11/76) to 8.7% (8/92) (P=0.239).
Implementation of the AED did not improve survival or a favourable neurological outcome in patients with OHCA due to VF/VT. However, with 5.7 min time to defibrillation, our EMS did not meet the criteria for early defibrillation. For prolonged periods of VT/VF, initial basic life support (BLS) may be superior to immediate AED. If response times of <4 min cannot be attained by the emergency systems, reconsidering of resuscitation algorithms seems to be advisable.
提倡使用自动体外除颤器（AED）进行早期除颤，以提高因无脉性室性心动过速（VT）和心室颤动（VF）导致的院外心脏骤停（OHCA）患者的生存率。然而，当VT/VF未得到治疗且持续数分钟以上时，使用AED除颤可能会失败。
这项回顾性研究回顾了1993年至2001年间当地紧急医疗服务（EMS）的病历，以评估AED引入EMS后的价值。对所有因VT/VF导致的目击OHCA病例进行分析；排除EMS目击的晕倒病例。主要终点定义为出院生存率和1年随访生存率，次要终点为无严重神经功能缺损的生存率。在实施AED之前，共治疗了76例因目击VT/VF导致的患者，实施之后治疗了92例。
在急救人员使用AED进行除颤之前，医生进行除颤的时间为15.6分钟（±5.5，标准差）。引入AED除颤后，急救人员进行除颤的时间为5.7分钟（±2.4，标准差）；从呼叫到除颤的平均反应间隔显著缩短（P<0.001）。同时，出院生存率从23.7%（18/76例患者）降至14.1%（13/92）（P=0.112），1年随访生存率从17.1%（13/76）降至9.8%（9/92）（P=0.161）。1年随访时良好的神经功能转归率也从14.5%（11/76）降至8.7%（8/92）（P=0.239）。
对于因VF/VT导致OHCA的患者，实施AED并未提高生存率或改善神经功能转归。然而，由于除颤时间为5.7分钟，我们的EMS未达到早期除颤的标准。对于长时间的VT/VF，初始基础生命支持（BLS）可能优于立即使用AED。如果急救系统无法达到<4分钟的反应时间，重新考虑复苏算法似乎是可取的。
