Overtime work of anesthesiologists is associated with increased delirium in older patients admitted to intensive care unit after noncardiac surgery: a secondary analysis

Overtime work is common in anesthesiologists due to shortage of manpower. Herein, we analyzed if overtime work of anesthesiologists was associated with delirium development in older patients after surgery.

This was a secondary analysis of the database from a randomized trial. Seven hundred older patients (aged ≥ 65 years) who were admitted to the intensive care unit (ICU) after elective noncardiac surgery were enrolled in the underlying trial. Anesthesiologists who worked continuously for more than 8 h by the end of the surgery were marked as “work overtime”. Delirium was assessed with the Confusion Assessment Method for the ICU twice daily during the first 7 postoperative days. The association between overtime work of anesthesiologists and development of postoperative delirium was analyzed with multivariable logistic regression models.

All 700 patients (mean age 74.3 years, 39.6% female) were included in this analysis. Anesthesiologists of 281 patients (40.1%) were marked as “work overtime” at the end of surgery. When compared with patients whose anesthesiologists didn’t work overtime, patients whose anesthesiologist worked overtime had a higher incidence of delirium within 7 days (20.3% [57/281] vs. 12.9% [54/419], P = 0.009). After correction for confounding factors, both overtime work (OR 1.87, 95% CI 1.19–2.94, P = 0.007) and prolonged continuous working hours of anesthesiologists (OR 1.08, 95% CI 1.01–1.15, P = 0.020) were associated with an increased risk of postoperative delirium.

Overtime work of anesthesiologists was associated with an increased risk of delirium development in older patients admitted to ICU after major noncardiac surgery.

The underlying trial was registered with Chinese Clinical Trial Registry (https://www.chictr.org.cn/showproj.html?proj=8734; ChiCTR-TRC-10000802; March 18, 2010).