Preliminary Analysis of Factors Associated with Blood Loss in Neuromuscular Scoliosis Surgery

A retrospective review was conducted of 57 consecutive patients (26 female; mean age: 16.6 years) who underwent posterior or combined anterior-posterior spinal fusion for neuromuscular scoliosis (NMS) from 2006 and 2007.

We aimed to assess which patient and surgical factors are predictive of increased blood loss and transfusion requirements during spinal fusion for NMS.

Spinal fusion surgery in patients with NMS has been associated with significant intraoperative blood loss and transfusion requirements. Specific factors predictive of greater blood loss have not been delineated; recognizing these factors will assist predicting the need for blood products and antifibrinolytics.

Data gathered included demographic, operative (operative time, levels fused, estimated blood loss, cell saver transfused, IV fluids transfused, and units transfused), and laboratory parameters (hemoglobin, hematocrit, platelet count, prothrombin time, partial prothrombin time, and international normalized ratio). Multivariate linear regression was used to identify parameters associated with greater intraoperative blood loss and transfusion requirements.

Eighty-three percent of patients underwent primary surgery with mean levels fused of 13.5. Regression analysis showed a statistically significant increase in blood loss with age (p = 0.00), operative time (p = 0.00), and postoperative platelets (p = 0.016). Each year of increasing age corresponded with an increase of 50 cc of estimated blood loss (EBL). Each additional hour of operative time was associated with an additional EBL of 147.7 cc. Each additional unit of postoperative platelets was associated with an EBL decrease of 2.8 cc. Units transfused increased with age (p = 0.00): each year of increasing age corresponded with an increase of 0.04 units of blood transfused.

Patients with NMS remain a challenging group of patients to treat. We find that age, operative time, and postoperative platelets are predictive of increased blood loss while only age was related to greater transfused units. Our findings may predict the need for blood products and antifibrinolytic agents preoperatively in this heterogeneous population, especially as patients age.