Abstract 264: CPR Quality is More Variable at Night Than During the Day in a Multicenter Study of in-hospital Cardiac Arrest.
Background: Recent work has shown that survival from in-hospital cardiac arrest (IHCA) is higher during the day than at night, especially in the ward setting (outside of the ICU). The reasons for this outcome variation remain unclear. High quality CPR has been shown to confer survival benefit from cardiac arrest; it is unknown whether CPR quality varies during IHCA between day and night.
Objective: We hypothesized that CPR quality (as measured by compression rate, depth and pre/post shock pauses) would be higher and less variable during the day than at night in ward IHCA events.
Methods: We examined consecutive adult IHCAs at three study hospitals from 4/2006–5/2010. Time of arrest was dichotomized as day (7:00 AM–10:59 PM) or night (11:00 PM–6:59 AM) following previously published definitions. Quality of CPR was assessed by quantifying chest compression rate, depth, and duration of pre-and post-shock pauses via CPR-recording monitor/defibrillators. Data were analyzed using standard descriptive and comparative statistics.
Results: Data were collected from 820 IHCAs of which 173 occurred on inpatient wards. In this ward subset, mean subject age was 66±15 years, and 47% were male. Survival to discharge in this subset was 15%. Mean chest compression rate was lower at night compared to day (101.6±16.1 per min vs.106.6±6.5 per min; p=.002) with a significantly larger compression rate variance at night (p<0.001). There was a trend towards increasing compression depth during day (47.9±8.6 mm vs 45.6±8.7 mm; p=NS). Daytime events had shorter mean pre-shock pauses (11.9± 18.0 sec vs 15.8±15.4 sec; p=NS) and shorter post-shock pauses (2.8±1.8 sec vs 4.6±5.0 sec; p=0.042) with a statistically significant post-shock pause variance (p<0.001). There was a small trend towards lower post-arrest survival at night compared to day (14.0% vs 15.5%, p=NS).
Conclusions: Resuscitation efforts occurring at night on hospital wards exhibit lower and more variable chest compression rates, as well as increased pre-and post-shock pause times, compared to IHCA resuscitation care during the day. This variation may partially explain the clinical survival difference measured in previous investigations, and has implications for hospital staffing and training to improve IHCA outcomes.
- © 2010 by American Heart Association, Inc.