The effect of blood transfusion on short-term, perioperative outcomes in elective spine surgery.

Studies in various surgical procedures have shown that transfusion of red blood cells (RBC) increases the risk of postoperative morbidity and mortality. Impact of blood transfusion in patients undergoing spine surgery is not well-described. We assessed the impact of intra and postoperative transfusion on postoperative morbidity and mortality in patients undergoing elective spine surgery. We used the American College of Surgeons' National Surgical Quality Improvement Program to identify a retrospective cohort of 36,901 adult patients who underwent elective spine surgery between 2006 and 2011. Patients who received intra or postoperative transfusion (n=3262) were matched to those who did not using propensity scores. Logistic regression predicted adverse postoperative outcomes. We conducted sensitivity analysis in a subset of patients in whom the number of intraoperatively transfused units of RBC or whole blood was known. Upon matching, preoperative hematocrit, length of surgery, and percentage of spinal fusion surgery were not significantly different between transfused and non-transfused patients. After matching, transfusion remained adversely associated with prolonged length of stay (LOS) in hospital (odds ratio [OR] 2.6, 95% confidence interval [CI] 2.3-2.9), postoperative complications (OR 1.6, 95% CI 1.4-1.9), and an increased 30 day return to operation room (OR 1.7, 95% CI 1.3-2.2). Transfusion of even one unit of blood intraoperatively was associated with prolonged LOS (OR 2.0, 95% CI 1.5-2.6) and minor complications (OR 2.4, 95% CI 1.3-4.3). Therefore, transfusion of RBC or whole blood, even a single unit, increased LOS and postoperative morbidity in patients undergoing elective spine surgery, independent of preoperative hematocrit level and patient comorbidities.