Incidence of and Risk Factors for Loss of 1 Blood Volume during Spinal Fusion Surgery in Patients with Cerebral Palsy

Background: Spinal fusion surgery is associated with greater blood loss in patients with cerebral palsy (CP) than in patients with adolescent idiopathic scoliosis. Risk factors for loss of 1 blood volume (LOBV) in patients with CP have not been well studied. We investigated the incidence of and risk factors for LOBV during spinal fusion surgery in young patients with CP. Methods: We queried a multicenter registry of CP patients for all patients 21 years or younger who had undergone spinal fusion from 2008 through 2013; 272 patients met these criteria. We analyzed data on patient characteristics, preoperative laboratory values, radiographic measures, and surgical characteristics. For univariate analysis, we used χ 2 tests and logistic regression models. Factors that were significant in the univariate analysis were used to construct a multivariate logistic regression model. Significance was set at P<0.01. Results: Incidence of LOBV was 39.7%. On multivariate analysis, unit rod construct and coronal curve magnitude were significantly associated with LOBV (P<0.01). The multivariate model accounted for 32.2% of variance in LOBV. Compared with patients with pedicle screw-rod constructs, patients with unit rod constructs had 12.6-fold higher odds of LOBV (P<0.01). For each 1-degree increase in coronal curve magnitude, odds of LOBV increased 1.03-fold (P<0.01). Conclusions: In patients with CP, there is a substantial risk of LOBV during spinal fusion surgery. Use of unit rod constructs and greater preoperative coronal curves were significant risk factors for LOBV during surgery. Level of Evidence: Level II.