Mortality and cardiac arrest rates of emergency surgery in developed and developing countries: a systematic review and meta-analysis

The magnitude of the risk of death and cardiac arrest associated with emergency surgery and anesthesia is not well understood. Our aim was to assess whether the risk of perioperative and anesthesia-related death and cardiac arrest has decreased over the years, and whether the rates of decrease are consistent between developed and developing countries. A systematic review was performed using electronic databases to identify studies in which patients underwent emergency surgery with rates of perioperative mortality, 30-day postoperative mortality, or perioperative cardiac arrest. Meta-regression and proportional meta-analysis with 95% confidence intervals (CIs) were performed to evaluate global data on the above three indicators over time and according to country Human Development Index (HDI), and to compare these results according to country HDI status (low vs. high HDI) and time period (pre-2000s vs. post-2000s). 35 studies met the inclusion criteria, representing more than 3.09 million anesthetic administrations to patients undergoing anesthesia for emergency surgery. Meta-regression showed a significant association between the risk of perioperative mortality and time (slope: -0.0421, 95%CI: from - 0.0685 to -0.0157; P = 0.0018). Perioperative mortality decreased over time from 227 per 10,000 (95% CI 134-380) before the 2000s to 46 (16-132) in the 2000-2020 s (p