Abstract 10858: Does Early Resumption of Chest Compressions After Successful Prehospital Defibrillation Increase the Risk for Early Recurrence of Ventricular Fibrillation?
Background: Prior investigation of out-of-hospital cardiac arrest (OHCA) has raised the possibility that patients with an initial rhythm of ventricular fibrillation (VF) may be more likely to experience recurrent VF within 2 seconds (sec) of the resumption of chest compressions (CC) after successful defibrillation. We sought to investigate whether early CC resumption increases the risk for VF recurrence within 30 seconds after successful defibrillation.
Methods: Adult patients with witnessed OHCA and an initial rhythm of VF from an Utstein-style database (collected from 2 sites in Arizona) were included. For each shock that succeeded in defibrillating VF, the time to resumption of CC and time to recurrence of VF were measured using electronic waveform data. CC resumption was further categorized into four pre-specified groups: CC1: 1-5 sec, CC2:6-10 sec, CC3: 11-30 sec, and CC4: >30 sec after shock. A Kaplan-Meier survival analysis for VF recurrence was performed by CC group.
Results: 89 adult OHCA cases were analyzed (70 M, 19 F, age=62± 15 y), with a median of 2 shocks/patient (range 1-11, 288 shocks with 226 being successful). Following a successful shock, CC resumption occurred at a mean of 17 ± 28 sec. Numbers of successful shocks per CC group were: [CC1, CC2, CC3, CC4]=[58,60,56,52], respectively. VF recurred after 164 shocks, with a mean of 113 ± 193 sec post shock. VF recurred within 30 sec in only 69 shocks. Hazard ratios for VF recurrence within 30 sec for later CC groups (CC2, CC3 and CC4) relative to early CC resumption (CC1) were: HR(CC2)=1.05 (p=0.9), HR(CC3)=1.93 (p=0.07), HR(CC4)=0.78 (p=0.6).
Conclusions: The risk of VF recurrence within 30 sec of a successful defibrillatory shock was not dependent upon timing of CC resumption in patients with witnessed arrest and initial rhythm of VF.
- © 2013 by American Heart Association, Inc.