Extended Anesthesiologist Work Periods and Postoperative Outcomes

Key Takeaways

• The adjusted composite outcome was not significantly different between extended and standard work periods.
• Extended work periods were associated with higher adjusted in-hospital mortality.
• Sensitivity analyses were directionally similar overall, and prespecified subgroup analyses were not significantly different.

In a JAMA Network Open analysis, cases that began after an attending anesthesiologist had worked continuously for at least 16 hours showed no significant adjusted difference in the primary composite outcome. Adjusted in-hospital mortality was higher during these extended work periods, at 1.3% versus 1.0%, for an absolute risk difference of 0.3%. The comparison was between extended and standard work periods rather than between different clinicians or hospitals. Overall, absolute differences were small, and the primary composite remained nonsignificant in the main adjusted analysis.

Researchers used data from the Multicenter Perioperative Outcomes Group registry in a cross-sectional study spanning January 1, 2010, to August 30, 2020. The cohort included 1,648,720 surgical procedures involving 1,711 anesthesiologists across 36 institutions, and 11,556 procedures, or 0.7%, met the extended-work definition. Exposure was defined as the attending anesthesiologist having worked continuously in intraoperative care for 16 hours or longer when the case started. The primary outcome was in-hospital mortality or major complication, and models adjusted for demographics, comorbidities, ASA physical status, emergency status, surgical start hour, and surgery type. The analysis therefore compared extended and standard work periods within the same anesthesiologists over time.

In adjusted analyses, composite outcome incidence was 12.1% during extended work periods and 12.0% during standard periods, a risk difference of 0.1%. The 95% CI ranged from −0.4% to 0.5%, and the P value was .82, indicating no significant difference for the primary end point. Adjusted in-hospital mortality was 1.3% versus 1.0%, with a 0.3% risk difference, a 95% CI of 0.1% to 0.5%, and P=.009. The unadjusted composite incidence was 12.3% versus 12.0%, and secondary outcomes included myocardial infarction, stroke, thromboembolic events, acute kidney injury, anesthesia-related complications, major respiratory complications, and mesenteric ischemia. Mortality was the clearest secondary signal, while most other secondary outcomes were not statistically significant.

No significant subgroup differences appeared among higher-risk patients, cases with trainees, nurse anesthetists, or anesthesia assistants, or across cardiovascular, orthopedic, urologic, and neurosurgical procedures. Sensitivity analyses tested 12- and 20-hour thresholds, with the 12-hour model showing a 1.1% risk difference, 95% CI 0.8% to 1.5%, P<.001, and the 20-hour model showing no difference. Ordinal modeling also showed higher risk in the 16 to less than 18 hour and 18 to less than 20 hour bands. The retrospective cross-sectional design left room for unmeasured confounding, captured only in-hospital predischarge outcomes, and relied on case sign-ins rather than all work tasks. With many centers being academic and no anesthesiologist demographic or experience data available, the findings raised concern about fatigue and patient safety but did not establish causation.