Pre-shock chest compression pause effects on termination of ventricular fibrillation/tachycardia and return of organized rhythm within mechanical and manual cardiopulmonary resuscitation

Resuscitation. 2015 Aug:93:158-63. doi: 10.1016/j.resuscitation.2015.04.023. Epub 2015 Apr 28.

Abstract

Background: Shorter manual chest compression pauses prior to defibrillation attempts is reported to improve the defibrillation success rate. Mechanical load-distributing band (LDB-) CPR enables shocks without compression pause. We studied pre-shock pause and termination of ventricular fibrillation/pulseless ventricular tachycardia 5s post-shock (TOF) and return of organized rhythm (ROOR) with LDB and manual (M-) CPR.

Methods: In a secondary analysis from the Circulation Improving Resuscitation Care trial, patients with initial shockable rhythm and interpretable post-shock rhythms were included. Pre-shock rhythm, pause duration (if any), and post-shock rhythm were obtained for each shock. Associations between TOF/ROOR and pre-shock pause duration, including no pause shocks with LDB-CPR, were analyzed with Chi-square test. A p-value <0.05 was considered statistically significant.

Results: For TOF and ROOR analyses we included 417 LDB-CPR patients with 1476 and 1438 shocks, and 495 M-CPR patients with 1839 and 1796 shocks, respectively. For first shocks with LDB-CPR, pre-shock pause was associated with TOF (p=0.049) with lowest TOF (77%) for shocks given without pre-shock compression pause. This association was not significant when all shocks were included (p=0.07) and not for ROOR. With M-CPR there were no significant associations between shock-related chest compression pause duration and TOF or ROOR.

Conclusion: For first shocks with LDB-CPR, termination of fibrillation was associated with pre-shock pause duration. There was no association for the rate of return of organized rhythm. For M-CPR, where no shocks were given during continuous chest compressions, there were no associations between pre-shock pause duration and TOF or ROOR.

Keywords: CPR; Cardiac arrest; Defibrillation; Emergency medical services; Mechanical CPR.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cardiopulmonary Resuscitation* / instrumentation
  • Cardiopulmonary Resuscitation* / methods
  • Defibrillators
  • Female
  • Humans
  • Male
  • Middle Aged
  • Myocardial Contraction
  • Out-of-Hospital Cardiac Arrest* / etiology
  • Out-of-Hospital Cardiac Arrest* / therapy
  • Outcome Assessment, Health Care
  • Pulsatile Flow*
  • Shock* / etiology
  • Shock* / physiopathology
  • Tachycardia, Ventricular* / complications
  • Tachycardia, Ventricular* / therapy
  • Time Factors
  • Ventricular Fibrillation* / complications
  • Ventricular Fibrillation* / therapy