Are abnormal preoperative hematological screening tests associated with allogeneic transfusion in idiopathic scoliosis surgery?

Purpose: Previous studies have suggested routine preoperative laboratory assessment may be unnecessary or excessive. The primary aim of this study was to determine the association between abnormal preoperative laboratory screening tests on allogeneic transfusion in pediatric patients receiving posterior spinal fusion for idiopathic scoliosis correction.

Methods: The NSQIP Pediatric database for years 2016-2022 was used. Patients who were (1) < 18 years old, (2) received posterior arthrodesis for idiopathic scoliosis correction, and (3) had recorded preoperative laboratory tests were included in this study. Preoperative bloodwork values of interest were hematocrit, albumin, platelet count, international normalized ratio (INR), and partial thromboplastin time (PTT). Descriptive statistics were used to characterize patient demographics, surgical metrics, and preoperative laboratory values. Rate of allogeneic transfusion was stratified by laboratory value cut-offs and compared using G-test. Standardized cut-offs were used to define abnormal values. A multivariable logistic regression analysis was used to assess the impact of abnormal bloodwork values on rate of allogeneic transfusion.

Results: There were 6057 patients included in this study. The mean age was 13.8 years. There were 13.6% that received allogeneic transfusion. The mean transfusion volume was 62.1 mL. Patients with abnormal preoperative INR (13.1% vs. 20.0%; p < 0.001), hematocrit < 35 (12.4% vs. 25.9%; p < 0.001), and albumin < 3.4 (13.4% vs. 25.8%; p = 0.004) had higher rates of transfusion. In the multivariable logistic regression analysis, INR > 1.2 (OR 1.4, p = 0.023) and hematocrit < 35 (OR 2.3, p < 0.001) were significantly associated with higher odds of allogeneic transfusion.

Conclusion: Preoperative INR and hematocrit values can aid in risk stratification for allogeneic transfusion requirements. PTT and platelet count did not significantly impact perioperative transfusion rates or volumes.