Time of day is not associated with increased rates of mortality in emergency surgery: An analysis of 49,196 surgical procedures

Abstract

Study objective: There is a lack of large, multi-institutional studies analyzing the association of timing of emergency surgery with death occurring either intraoperatively or in the recovery room setting. The primary objective of this study was to determine if time of day for emergency surgeries was associated with mortality.

Design: Retrospective analysis.

Setting: U.S. healthcare facilities.

Patients: Adult patients undergoing emergency surgery and general anesthesia.

Interventions: No intervention.

Measurements: Utilizing the National Anesthesia Clinical Outcomes Registry database, all emergency non-cardiac, non-obstetric surgeries undergoing general anesthesia occurring between 2010 and 2015 in the United States were identified. We performed mixed effects logistic regression to determine the effect of time of day with mortality occurring during the intraoperative and immediate postoperative period.

Main results: There were 46,196 cases that were eligible for this analysis, in which 24,247 and 21,949 occurred during day and after-hours shifts, respectively. The overall morality rate was 0.28%. Mortality rates were 0.17% and 0.41% in the day and after-hour shifts, respectively. There was no statistically significant association of time of day with mortality (odds ratio 1.31, 95% CI 0.90-1.92, p = 0.16). American Society of Anesthesiologists physical status classification, age, and operative body part were all associated with mortality.

Conclusions: Although, theoretically, health care providers working after-hour shifts may be impacted by sleep deprivation and/or limited resources, we found that time of day was not associated with increased risk of mortality during the intraoperative and immediate postoperative period in emergency surgery.

Keywords: Anesthesia; Complications; Emergency surgery; Mortality; Outcomes; Time of day.