Association between surgical resident involvement and blood use in noncardiac surgery

Although there is significant variability in the rate of blood transfusion in surgical patients, the role of surgical skill as a determinant of blood use is unknown.

We examined the association between surgery resident participation and intraoperative blood transfusion, and 30-day mortality and complications, among 381,036 patients undergoing noncardiac surgery, adjusting for patient factors and procedure complexity.

Compared to attending surgeons working without a resident, cases in which the attendings worked with either Postgraduate Year (PGY) 3 to 4 resident or a PGY5 to 8 resident had a 56% (adjusted odds ratio [AOR], 1.56; 95% confidence interval [CI, 1.48-1.64) or a 78% (AOR, 1.78; 95% CI, 1.70-1.87) higher odds of receiving a blood transfusion, respectively. Involvement of surgical interns or junior residents (PGY1-2), whose role in the operative procedure is assumed to be limited, was associated with a 27% higher odds of receiving a blood transfusion (AOR, 1.27; 95% CI, 1.18-1.37). Overall, resident involvement was not associated with increased risk of 30-day mortality (AOR, 0.97; 95% CI, 0.91-1.04), but was associated with a slightly increased risk of complications (AOR, 1.13; 95% CI, 1.10-1.16).

Senior surgery resident participation in noncardiac surgery is associated with between a 56% to 78% higher risk of receiving a blood transfusion intraoperatively compared to attending surgeons working without a resident. Assuming that senior surgical trainees are performing critical parts of the operative procedure and are less skilled than attending surgeons, the findings from this exploratory study suggest that intraoperative blood transfusion may serve as an indirect measure of surgical technical quality.