A study of preoperative triggers to prospectively identify cases at risk of adverse events in non-operating room anesthesia

Traditional methods to investigate adverse events incompletely identify events that may cause patient harm. Trigger tool methodology uses surveillance algorithms of patient-level data to flag patterns consistent with adverse events. This methodology can be adapted to non-operating room anesthesia (NORA) and the need for prospective action to prevent patient harm. The first step is to use retrospective data to develop a trigger tool for use in preoperative case planning. This case control study used NORA gastroenterology (GI) cases from the Anesthesia Closed Claims Project as cases with adverse events and from the National Anesthesia Clinical Outcomes Registry as controls (procedures not associated with adverse events). Structured analysis of detailed narrative information from cases was used to identify additional triggers. Cases were more likely to be American Society of Anesthesiologists Physical Status 3–5 (71 %) than controls (43 %, OR 3.17, p < 0.001), conducted on an emergency basis (12 % cases vs. 0.4 % controls, OR 30.3, p < 0.001), involved monitored anesthesia care (88 % cases vs. 49 % controls, OR 7.55, p < 0.001), and more commonly performed on inpatients (OR 1.725, p = 0.042). Structured narrative analysis identified triggers in 84 % of cases. The most common triggers were ASA PS 3–5 (69 %), cardiovascular comorbidities (46 %), gastrointestinal conditions (37 %), and morbid obesity (30 %). Injuries were more severe in cases with triggers than cases without triggers (p = 0.003). Reducing the risk of severe complications with use of a pre-procedure trigger tool for NORA with resultant change in anesthetic plan could potentially reduce preventable harm in thousands of patients per year in the United States.