Association between night-time surgery and occurrence of intraoperative adverse events and postoperative pulmonary complications

Abstract

Background: The aim of this post hoc analysis of a large cohort study was to evaluate the association between night-time surgery and the occurrence of intraoperative adverse events (AEs) and postoperative pulmonary complications (PPCs). Methods: LAS VEGAS (Local Assessment of Ventilatory Management During General Anesthesia for Surgery) was a prospective international 1-week study that enrolled adult patients undergoing surgical procedures with general anaesthesia and mechanical ventilation in 146 hospitals across 29 countries. Surgeries were defined as occurring during `daytime' when induction of anaesthesia was between 8: 00 AM and 7: 59 PM, and as `night-time' when induction was between 8: 00 PM and 7: 59 AM. Results: Of 9861 included patients, 555 (5.6\%) underwent surgery during night-time. The proportion of patients who developed intraoperative AEs was higher during night-time surgery in unmatched (43.6\% vs 34.1\%

P<0.001) and propensity-matched analyses (43.7\% vs 36.8\%

P = 0.029). PPCs also occurred more often in patients who underwent night-time surgery (14\% vs 10\%

P = 0.004) in an unmatched cohort analysis, although not in a propensity-matched analysis (13.8\% vs 11.8\%

P = 0.39). In a multivariable regression model, including patient characteristics and types of surgery and anaesthesia, night-time surgery was independently associated with a higher incidence of intraoperative AEs (odds ratio: 1.44

95\% confidence interval: 1.09-1.90

P = 0.01), but not with a higher incidence of PPCs (odds ratio: 1.32

95\% confidence interval: 0.89-1.90

P = 0.15). Conclusions: Intraoperative adverse events and postoperative pulmonary complications occurred more often in patients undergoing night-time surgery. Imbalances in patients' clinical characteristics, types of surgery, and intraoperative management at night-time partially explained the higher incidence of postoperative pulmonary complications, but not the higher incidence of adverse events.