PACU Outcomes Across Anesthesiology Resident Training Levels: A Retrospective Cohort Study

Background: Opioid use, antiemetic administration, and length of postanesthesia care unit (PACU) stay are commonly documented postoperative recovery measures. The extent to which they differ across anesthesiology resident training levels independent of patient and procedural factors remains uncertain. Characterizing these patterns may help distinguish differences attributable to patient or procedural factors from those related to resident experience. Objective: To explore whether PACU recovery outcomes differ across anesthesiology resident training levels. Methods: This single-center retrospective cohort study analyzed 7699 adult nonobstetric anesthetics performed between October 2024 and May 2025, stratified by resident level (first-, second-, or third-year clinical anesthesia resident). The primary outcome was PACU morphine milligram equivalents. Secondary outcomes were rescue antiemetic use and recovery time. Univariable tests, Tukey-adjusted comparisons, and multivariable linear regressions adjusted for demographics, case characteristics, and anesthetic type. Results: Patient and case characteristics varied across resident levels. After multivariable adjustment, resident training level was not independently associated with PACU opioid use, rescue antiemetic administration, or recovery time. Unadjusted variation in these recovery measures was explained by patient and procedural factors. Conclusions: Resident training level was not an independent predictor of PACU opioid use, rescue antiemetic administration, or recovery time. Observed differences were explained by patient and procedural factors, and this highlights the complex interplay of patient comorbidities, surgical characteristics, anesthetic plans, and institutional protocols on postanesthesia recovery metrics and emphasizes the importance of case-mix adjustment when interpreting PACU outcomes in educational contexts.