Risk analysis of blood transfusion requirements in emergency and elective spinal surgery

Spinal surgery has long been considered to have an elevated risk of perioperative blood loss with significant associated blood transfusion requirements. However, a great variability exists in the blood loss and transfusion requirements of differing patients and differing procedures in the area of spinal surgery. We performed a retrospective study of all patients undergoing spinal surgery who required a transfusion >= 1 U of red blood cells (RBC) at the National Spinal Injuries Unit (NSIU) at the Mater Misericordiae University Hospital over a 10-year period. The purpose of this study was to identify risk factors associated with significant perioperative transfusion allowing the early recognition of patients at greatest risk, and to improve existing transfusion practices allowing safer, more appropriate blood product allocation. 1,596 surgical procedures were performed at the NSIU over a 10-year period. 25.9% (414/1,596) of these cases required a blood transfusion (n = 414). Surgical groups with a significant risk of requiring a transfusion > 2 U RBC included deformity surgery (RR = 3.351, 95% CI 1.123-10.006, p = 0.03), tumor surgery (RR = 3.298, 95% CI 1.078-10.089, p = 0.036), and trauma surgery (RR = 2.444, 95% CI 1.183-5.050, p = 0.036). Multivariable logistic regression analysis identified multilevel surgery (> 3 levels) as a significant risk of requiring a transfusion > 2 U RBC (RR = 4.682, 95% CI 2.654-8.261, p < 0.0001). Several risk factors in the spinal surgery patient were identified as corresponding to significant transfusion requirements. A greater awareness of the risk factors associated with transfusion is required in order to optimize patient management.