Survival from in-hospital cardiac arrest during nights and weekends

Context Occurrence of in- hospital cardiac arrest and survival patterns have not been characterized by time of day or day of week. Patient physiology and process of care for in- hospital cardiac arrest may be different at night and on weekends because of hospital factors unrelated to patient, event, or location variables. Objective To determine whether outcomes after in- hospital cardiac arrest differ during nights and weekends compared with days/ evenings and weekdays. Design and Setting We examined survival from cardiac arrest in hourly time segments, defining day/ evening as 7: 00 AM to 10: 59 PM, night as 11: 00 PM to 6: 59 AM, and weekend as 11: 00 PM on Friday to 6: 59 AM on Monday, in 86 748 adult, consecutive in- hospital cardiac arrest events in the National Registry of Cardiopulmonary Resuscitation obtained from 507 medical/ surgical participating hospitals from January 1, 2000, through February 1, 2007. Main Outcome Measures The primary outcome of survival to discharge and secondary outcomes of survival of the event, 24- hour survival, and favorable neurological outcome were compared using odds ratios and multivariable logistic regression analysis. Point estimates of survival outcomes are reported as percentages with 95% confidence intervals ( 95% CIs). Results A total of 58 593 cases of in- hospital cardiac arrest occurred during day/ evening hours ( including 43 483 on weekdays and 15 110 on weekends), and 28 155 cases occurred during night hours ( including 20 365 on weekdays and 7790 on weekends). Rates of survival to discharge ( 14.7% [ 95% CI, 14.3%- 15.1%] vs 19.8% [ 95% CI, 19.5%- 20.1%], return of spontaneous circulation for longer than 20 minutes ( 44.7% [ 95% CI, 44.1%- 45.3%] vs 51.1% [ 95% CI, 50.7%- 51.5%]), survival at 24 hours ( 28.9% [ 95% CI, 28.4%- 29.4%] vs 35.4% [ 95% CI, 35.0%- 35.8%]), and favorable neurological outcomes ( 11.0% [ 95% CI, 10.6%- 11.4%] vs 15.2% [ 95% CI, 14.9%-15.5%]) were substantially lower during the night compared with day/ evening ( all P values <. 001). The first documented rhythm at night was more frequently asystole ( 39.6% [ 95% CI, 39.0%- 40.2%] vs 33.5% [ 95% CI, 33.2%- 33.9%], P <. 001) and less frequently ventricular fibrillation ( 19.8% [ 95% CI, 19.3%- 20.2%] vs 22.9% [ 95% CI, 22.6%- 23.2%], P <. 001). Among in- hospital cardiac arrests occurring during day/ evening hours, survival was higher on weekdays ( 20.6% [ 95% CI, 20.3%- 21%]) than on weekends ( 17.4% [ 95% CI, 16.8%- 18%]; odds ratio, 1.15 [ 95% CI, 1.09- 1.22]), whereas among in- hospital cardiac arrests occurring during night hours, survival to discharge was similar on weekdays ( 14.6% [ 95% CI, 14.1%- 15.2%]) and on weekends ( 14.8% [ 95% CI, 14.1%- 15.2%]; odds ratio, 1.02 [ 95% CI, 0.94- 1.11]). Conclusion Survival rates from in- hospital cardiac arrest are lower during nights and weekends, even when adjusted for potentially confounding patient, event, and hospital characteristics.