Abstract 266: Peri-Shock Pause: an Independent Predictor of Survival From Out-of-Hospital Shockable Cardiac Arrest
Introduction: Peri-shock pauses, defined as the pauses before and after defibrillatory shock interrupt chest compressions and are associated with reduced defibrillation success rates. We examined the relationship between peri-shock pauses and survival to discharge in an out-of-hospital cardiac arrest (OHCA) registry.
Hypothesis: Longer peri-shock pause intervals are associated with decreased survival to discharge.
Methods: We included OHCA patients in the Resuscitation Outcomes Consortium (ROC) Epistry-Cardiac Arrest who suffered arrest between December 2005 and June 2007, presented with VF/VT and had CPR process data for at least one shock (n=839). Trained data abstractors used explicit definitions to record peri-shock pause intervals. We used multivariable logistic regression (for up to the first three shocks) to determine the association between survival and peri-shock pauses. Models were adjusted for ROC site, demographic (age, gender), circumstance (location, witness status), and care (bystander CPR, EMS response time) characteristics.
Results: Descriptive: The median peri-shock pause (pre+post) was 30 seconds (s) (IQR=22 s). The median pre-shock pause was 20 s (IQR=14 s) and the median post-shock pause was 12 s (IQR=20 s). Multivariable regression using the longest pause showed: A) peri-shock, n=672: Compared to patients with peri-shock pause <20 s, the odds of surviving to discharge were 32% lower (OR: 0.68, 95%CI: 0.42, 1.11) for patients with peri-shock pause 20–40 s and 55% lower (OR: 0.45, 95%CI: 0.26, 0.77) for patients with peri-shock pause ≥40 s. B) pre-shock, n=697: Compared to patients with pre-shock pause <10 s, the odds of surviving to discharge were 26% lower (OR: 0.74, 95%CI: 0.42, 1.30) for patients with pre-shock pause 10–20 s and 52% lower (OR: 0.48, 95%CI: 0.29, 0.80) for patients with pre-shock pause ≥20 s. C) post-shock, n=679: Compared to patients with post-shock pause <10 s, the odds of surviving to discharge were 3% lower (OR: 0.97, 95%CI: 0.62, 1.52) for patients with post-shock pause of 10–20 s and 17% lower (OR: 0.83, 95%CI: 0.51, 1.34) for patients with post-shock pause ≥20 s.
Conclusions: Peri-shock pause was an independent predictor of survival to discharge in this cardiac arrest registry.
- © 2010 by American Heart Association, Inc.