Anesthesia-related perioperative adverse events during in-patient and out-patient procedures

This paper aims to determine the one-year incidence of, and risk factors for, perioperative adverse events during in-patient and out-patient anesthesia-assisted procedures.

A quality assurance database was the primary data source. Outcome variables were death and the occurrence of any adverse event. Risk factors were ASA physical status (PS), age, duration and type of anesthesia care, number of operating rooms running, concurrency level and medical staff. Data were stratified by in-patient or out-patient, surgical (e.g. thoracotomy) or non-surgical (e.g. electroconvulsive therapy), and were analyzed using Chi square, Fisher's exact test and generalized estimating equations.

Of 27,970 procedures, 49.8 percent were out-patient and greater than 80 percent were surgical. For surgical procedures, adverse event rates were higher for in-patient than out-patient procedures (2.11 percent vs. 1.45 percent; p < 0.001). For non-surgical procedures, adverse event rates were similar for in-patients and out-patients (0.54 percent vs. 0.36 percent). The types of adverseevents differed for in-patient and out-patient surgical procedures (p < 0.001), but not for non-surgical procedures. ASA PS, age, duration of anesthesia care, anesthesia type and medical staff assigned to the case were each associated with adverse event rates, but the association depended on the type of procedure.

In-patient and out-patient surgical procedures differ in the incidence of perioperative adverse events, and in risk factors, suggesting a need to develop separate monitoring strategies.

The paper is the first to assess perioperative adverse events amongst in-patient and out-patient procedures.