Video-recording and time-motion analyses of manual versus mechanical cardiopulmonary resuscitation during ambulance transport

Introduction: The quality of cardiopulmonary resuscitation (CPR) plays a crucial role in saving lives from out-of-hospital cardiac arrest (OHCA). Previous studies have identified sub-optimal CPR quality in the prehospital settings, but the causes leading to such deficiencies were not fully elucidated. Objective: This prospective study was conducted to identify operator-and ambulance-related factors affecting CPR quality during ambulance transport; and to assess the effectiveness of mechanical CPR device in such environment. Materials and methods: A digital video-recording system was set up in two ambulances in Taipei City to study CPR practice for adult, non-traumatic OHCAs from January 2005 to March 2006. Enrolled patients received either manual CPR or CPR by a mechanical device (Thumper). Quality of CPR in terms of (1) adequacy of chest compressions, (2) instantaneous compression rates, and (3) unnecessary no-chest compression interval, was assessed by time-motion analysis of the videos. Results: A total of 20 ambulance resuscitations were included. Compared to the manual group (n = 12), the Thumper group (n = 8) had similar no-chest compression interval (33.40% versus 31.63%, P=0.16); significantly tower average chest compression rate (113.3 +/- 47.1 min(-1) versus 52.3 +/- 14.2 min(-1), P < 0.05), average chest compression rate excluding no-chest compression interval (164.2 +/- 43.3 min(-1) versus 77.2 +/- 6.9 min(-1), P < 0.05), average ventilation rate(16.1 +/- 4.9 min(-1) versus 11.7 +/- 3.5 min(-1), P < 0.05); and longer no-chest compression interval before getting off the ambulance (5.7 +/- 9.9 s versus 18.7 +/- 9.1 s, P < 0.05). The majority of the no-chest compression interval was considered operator-related; only 15.3% was caused by ambulance related factors. Conclusions: Many unnecessary no-chest compression intervals were identified during ambulance CPR, and most of this was operator, rather than ambulance related. Though a mechanical device could minimise the no-chest compression intervals after activation, it took considerable time to deploy in a system with short transport time. Human factors remained the most important cause of poor CPR quality. Ways to improve the CPR quality in the ambulance warrant further study. (c) 2007 Elsevier Ireland Ltd. All rights reserved.