Eighteen-year trends in the rates of intra-operative cardiac arrest and associated mortality at a public university hospital in Brazil*

Background: Intra-operative cardiac arrest is a rare but life-threatening event. Over the past two decades, various initiatives have improved the care of patients undergoing surgery at our quaternary teaching hospital in Brazil. We aimed to evaluate the epidemiology of intra-operative cardiac arrest and associated 30-day mortality over an 18-year period. A secondary aim was to identify associated risk factors. Methods: We conducted a retrospective observational study using data collected from 1 January 2005 to 31 December 2022. Factors associated with cardiac arrest and mortality were identified using multivariable logistic regression analysis. Results: Among the 154,178 cases, the overall rates of intra-operative cardiac arrest (n = 297) and associated 30-day mortality (n = 248) were 19.3 (95%CI (16.6–21.9)) and 16.1 (95% CI 13.9–18.3) per 10,000 anaesthetics, respectively. These decreased over time (2005–2010 vs. 2017–2022) from 26.3 (95%CI 21.0–31.6) to 15.4 (95%CI 12.0–18.7) per 10,000 anaesthetics, and from 23.4 (95%CI 18.8–28.1) to 13.7 (95%CI 10.8–16.7) per 10,000 anaesthetics, respectively. Factors associated with intra-operative cardiac arrest included children aged < 1 year (adjusted OR (95%CI) 3.51 (1.87–6.57)); ASA physical status 3–5 (adjusted OR (95%CI) 13.85 (8.86–21.65)); emergency surgery (adjusted OR (95%CI) 10.06 (7.85–12.89)); general anaesthesia (adjusted OR (95%CI) 8.79 (4.60–19.64)); surgical procedure involving multiple specialities (adjusted OR (95%CI) 9.13 (4.24–19.64)); cardiac surgery (adjusted OR (95%CI) 7.69 (5.05–11.71)); vascular surgery (adjusted OR (95%CI) 6.21 (4.05–9.51)); and gastrointestinal surgery (adjusted OR (95%CI) 2.98 (1.91–4.65)). Discussion: We have shown an important reduction in intra-operative cardiac arrest and associated 30-day mortality over an 18-year period. Identification of relative risk factors associated with intra-operative cardiac arrest can be used to improve the safety and quality of patient care, especially in a resource-limited setting.