Comparison of Safety Profiles between Non-operating Room Anesthesia and Operating Room Anesthesia: a Study of 199,764 Cases at a Korean Tertiary Hospital

BACKGROUND: Despite expanding demands for non-operating room anesthesia (NORA) worldwide, studies in this field are scarce. We compared the overall characteristics and the nature of deaths occurring within 48 hours after surgery between NORA and operating room anesthesia (ORA) cases at a Korean tertiary hospital. METHODS: We retrospectively analyzed the medical records of patients who underwent surgical procedures under anesthesia services in and outside the operating room from January 2013 to November 2017. All of the mortalities were categorized by principal cause into groups such as patient disease or condition, surgery, anesthesia, and others. RESULTS: Overall, 16,383 NORA cases and 183,381 ORA cases were analyzed. Eighty-six deaths were identified. The mortality rate of NORA cases was similar to that of ORA cases (4.9 per 10,000 cases [95% confidence interval (CI), 2.1–9.6] vs. 4.3 per 10,000 cases [95% CI, 3.4–5.3], respectively). Similar to ORA cases, higher American Society of Anesthesiologists physical status and very young age (< 2 years) were significantly associated with mortality in NORA cases. A patient's disease or condition was the most important cause of mortality (65/86, 75.6%), followed by surgery-related causes (16/86, 18.6%). Two cases of anesthesia-related mortality were only identified in the ORA cases, resulting in an overall anesthesia-related mortality of 0.1 per 10,000 cases (95% CI, 0.0–0.4). CONCLUSION: Although NORA cases showed an equivalent perioperative mortality rate compared to ORA cases, there may be more room for improving patient safety when considering their favorable characteristics (healthier patients, less invasive and shorter procedures). TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0002719