‘After-hours’ non-elective spine surgery is associated with increased perioperative adverse events in a quaternary center

Purpose ‘After-hours’ non-elective spinal surgeries are frequently necessary, and often performed under sub-optimal conditions. This study aimed (1) to compare the characteristics of patients undergoing non-elective spine surgery ‘After-hours’ as compared to ‘In-hours’; and (2) to compare the perioperative adverse events (AEs) between those undergoing non-elective spine surgery ‘after-hours’ as compared to ‘in-hours’. Methods In this retrospective study of a prospective non-elective spine surgery cohort performed in a quaternary spine center, surgery was defined as ‘in-hours’ if performed between 0700 and 1600 h from Monday to Friday or ‘after-hours’ if more than 50% of the operative time occurred between 1601 and 0659 h, or if performed over the weekend. The association of ‘after-hours’ surgery with AEs, surgical duration, intraoperative estimated blood loss (IOBL), length of stay and in-hospital mortality was analyzed using stepwise multivariate logistic regression. Results A total of 1440 patients who underwent non-elective spinal surgery between 2009 and 2013 were included in this study. A total of 664 (46%) procedures were performed ‘after-hours’. Surgical duration and IOBL were similar. About 70% of the patients operated ‘after-hours’ experienced at least one AE compared to 64% for the ‘in-hours’ group ( p = 0.016). ‘After-hours’ surgery remained an independent predictor of AEs on multivariate analysis [adjusted OR 1.30, 95% confidence interval (CI) 1.02–1.66, p = 0.034]. In-hospital mortality increased twofold in patients operated ‘after-hours’ (4.4% vs. 2.1%, p = 0.013). This association lost significance on multivariate analysis (adjusted OR 1.99, 95% CI 0.98–4.06, p = 0.056). Conclusion Non-elective spine surgery performed ‘after-hours’ is independently associated with increased risk of perioperative adverse events, length of stay and possibly, mortality. Research is needed to determine the specific factors contributing to poorer outcomes with ‘after-hours’ surgery and strategies to minimize this risk. Graphical abstract These slides can be retrieved under Electronic Supplementary Material.