Association between preoperative hemoglobin levels after iron supplementation and perioperative blood transfusion requirements in children undergoing scoliosis surgery

Background and aims: In this study, we assessed the association between preoperative hemoglobin and red blood cell transfusion in children undergoing spine surgery after the implementation of our preoperative iron supplementation protocol.

Method: We performed a retrospective analysis of patients who underwent posterior spinal fusion surgery between January 2013 and December 2017 and received preoperative iron supplementation. We used uni- and multivariable logistic regression to determine the association between preoperative hemoglobin level and red blood cell transfusion in patients receiving iron supplementation.

Results: A total of 382 patients treated with preoperative oral iron were included. Of these, 175 (45.5%) patients were transfused intraoperatively. Multivariable logistic regression analysis revealed nonidiopathic etiology of the scoliosis (OR 4.178 [95% CI: 2.277-7.668], P < .001), the Cobb angle (OR 1.025 [95% CI: 1.010-1.040], P = .001), and number of vertebrae fused (OR 1.169 [95% CI: 1.042-1.312], P = .008) were associated with red blood cell transfusion. In addition, patients with a preoperative hemoglobin ≥ 140 g/L (OR 0.157 [95% CI: 0.046-0.540], P = .003), and hemoglobin between 130 and 140 g/L (OR 0.195 [95% CI: 0.057-0.669], P = .009) were less likely to be transfused compared with patients with preoperative hemoglobin between 120 and 130 g/L (OR 0.294 [95% CI: 0.780-1.082], P = .066) or <120 g/L (reference).

Conclusion: Our study suggests that higher preoperative hemoglobin levels (>130 g/L) are associated with a reduced need for red blood cell transfusion in pediatric patients who have received iron supplementation before undergoing posterior spinal fusion in our institution. The effect of iron supplementation, the optimal dosing, and duration of supplemental iron therapy remains unclear at this time.