Can Hospital Standard Manual Defibrillators Be Replaced By Automatic External Defibrillators: Results On A Simulated Model

摘要

Introduction: Although AED (automated external defibrillator) are being placed in many public places, standard manual defibrillator (SMD) still predominates in the hospital setting. Study Objective: Determine differences in time to first shock by residents comparing AED's to SMD's. Methods: Emergency Medicine residents were tested using both AED and SMD separately in simulated cardiac arrests. Measurements included time from discovery of the simulated cardiac arrest to first shock delivered. Results: Median times to first shock for 20 residents were: SMD) 86.0 seconds; AED) 80.25 seconds (difference, 0.5 second; 95%CI: -18.0 to 27.0; Wilcoxon P=0.985). SMD-AED differences for first-year residents (-28.5), second-year (25.7) and third-year (10.0) were not significantly different (Kruskal-Wallis P=0.85). Conclusion: The time to first shock for Emergency Medicine residents in all stages of training, was not impacted by their using AED or SMD. This study supports the decision to extend the placement of AED's to the hospital setting. Presented at: American College of Emergency Physicians Research Forum; October 2001; Chicago, Illinois Introduction The key to survival in cardiac arrest is early defibrillation.1,2,3,4,5,6 When time to first shock is five minutes, survival is 50% and falls of by 10% for each minute lost.7 The American Heart Association (AHA), in an advisory statement on this subject, writes that electrical defibrillation provides the single most important therapy for the treatment of sudden cardiac arrest. The AHA also recommends AED training for all healthcare providers and strategic placement of AED's throughout healthcare facilities.8 In fall 2001, the AHA amended Advanced Cardiovascular Life Support guidelines to include certification in the use of AEDs. Although AED's are being placed in many public places according to AHA recommendations,9,10,11,12,13 hospitals still rely on standard manual defibrillators (SMD's) for their resuscitations.6,14,15,16 The majority of studies involving AED's have examined their utility in non-hospital settings. In reported studies, paramedics, EMT's, police and security personnel have all shown that they can successfully use AED's.5,7,17,18,19,20 Few studies have looked at AED use in the hospital. In 1996, Destro, et al, proved that non-Critical care staff could successfully use AED's. As part of the study, AED's were placed in two non-Critical care units of his hospital and utilized during cardiac resuscitations that occurred on those two units. His data looked at outcome however, and not time to first shock.14 Our study objective was to determine if using AED's by ACLS certified residents could change the time to first shock when compared to their use of SMD's. Methods Study Design: This was a randomized controlled trial using emergency medicine residents with one to three post-graduate years (PGY) of training. Study Setting and Population: All residents were from a single emergency medicine residency program based at a 434-bed community teaching hospital. All residents were ACLS certified and as such had received training in AED use. Study Protocol: Upon approval and waiver of written consent from the IRB committee of the medical center, each resident volunteered to run two simulated code using AED for one and SMD for the other, thus serving as his or her own control. The trial order was randomized to both type of defibrillator used and level of training. A standard manual defibrillator ( LifePac model #9P, PhysioControl, Redmond, WA) and an automatic external defibrillator ( Heartstream model #FR2, Agilent Tech. , Seattle, WA ) were used. An independent assistant served as the “nurse” at the bedside. The assistant acted as a facilitator to the resident, much like an examiner in an oral boards test. His/her instructions were always short and were identical for each resident. For example, when the resident commented about checking or securing the patients airway, he/she would imme