Background: Handover of anaesthesia patient care during surgery is common; however, its association with patient outcome is unclear. This systematic review aimed to assess the impact of anaesthesia handover during surgery on patient outcome.

Methods: All prospective and retrospective clinical studies specifically investigating the association of intraoperative transfer of anaesthesia care between anaesthesia providers in the operating room with patient morbidity and mortality were included. Searches were conducted from inception to April 24, 2019 in Medline, Medline in Process, CINAHL, and Embase. Reference lists of included studies were searched. Studies were assessed for eligibility and data were extracted by independent reviewers in duplicate with disagreements resolved by consensus or a third reviewer. Risk of bias was assessed in duplicate using the National Institutes of Health Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies. Data were summarised narratively given substantial heterogeneity. An exploratory meta-analysis was conducted using a random-effects model for a subset of comparable studies.

Results: Eight studies met the inclusion criteria. Six studies focused on patients as the unit of analysis (n_patients =605 678) and two focused on anaesthesia providers as the unit of analysis (n_providers =307). Seven studies identified a relationship between anaesthesia handovers and adverse patient outcomes, whereas one suggested that handover may be beneficial to error detection or rectification. Included studies were of fair or good quality. Meta-analysis of four studies found a 40% increased risk of patients experiencing an adverse event when an anaesthesia handover occurs during the procedure (pooled risk ratio=1.40; 95% confidence interval, 1.19 to 1.65; P<0.001; I² =98%).

Conclusions: Intraoperative anaesthesia handovers generally increase morbidity and mortality for surgical patients but could have the potential to improve safety in certain contexts. Future research should determine the specific handover characteristics that impact safety.