Impact of Pre-operative Platelet Count on Bleeding Risk and Allogeneic Transfusion in Multi-Level Spine Surgery.

STUDY DESIGN This was an observational cohort study of patients receiving multi-level thoracic and lumbar spine surgery. OBJECTIVES To identify which patients are at high risk for allogeneic transfusion which may allow for better preoperative planning and employment of specific blood management strategies. SUMMARY OF BACKGROUND DATA Multi-level posterior spine surgery is associated with a significant risk for major blood loss, and allogeneic blood transfusion is common in spine surgery. METHODS A univariate logistic regression model was used to identify variables that were significantly associated with intra-operative allogeneic transfusion. A multivariate forward stepwise logistic regression model was then used to measure the adjusted association of these variables with intra-operative transfusion. RESULTS Multi-level thoracic and lumbar spine surgery was performed in 921 patients. When stratifying patients by pre-operative platelet count, patients with pre-operative thrombocytopenia and severe thrombocytopenia had a significantly higher rate of transfusion than those who were not thrombocytopenic. Furthermore, those with severe thrombocytopenia had a higher rate of RBC, FFP, and platelet transfusion than those with higher platelet counts. Multivariate logistic regression found that pre-operative platelet count was the most significant contributor to transfusion, with a platelet count ≤100 having an adjusted OR of transfusion of 4.88 (95% CI 1.58-15.02, p = 0.006). Similarly, a platelet count between 101-150 also doubled the risk of transfusion with an adjusted OR of 2.02 (95% CI 1.01-4.04, p = 0.047). The ASA classification score increased the OR of transfusion by 2.5 times (OR = 2.52, 95% CI 1.54-4.13), while pre-operative PT and age minimally increased the risk. CONCLUSION Pre-operative thrombocytopenia significantly contributes to intra-operative transfusion in multi-level thoracic lumbar spine surgery. Identifying factors that may increase the risk for transfusion could be of great benefit in better pre-operative counseling of patients and in reducing overall cost and postoperative complications by implementing strategies and techniques to reduce blood loss and blood transfusions. LEVEL OF EVIDENCE 2.