Modified shock index multiplied by gestational age as a predictor of the need for blood transfusion in patients with postpartum hemorrhage.

Abstract

Introduction: Previous studies have demonstrated that the shock index (SI), calculated as the ratio of heart rate (HR) to systolic blood pressure (SBP), and the modified shock index (MSI), calculated as the ratio of HR to mean arterial pressure (MAP), are reliable predictors of blood transfusion requirements in postpartum hemorrhage (PPH) patients. This study aimed to evaluate the predictive value of the modified shock index multiplied by gestational age (MSIGA) in comparison to traditional shock indices, including SI, reverse SI (RSI), and MSI, for predicting the need for blood transfusion in PPH.

Methods: This retrospective study included women diagnosed with PPH who delivered at our clinic between 2020 and 2023. Patients were divided into two groups: transfusion and non-transfusion. The transfusion group included patients who required at least one blood and/or blood product transfusion within 24 hours after delivery. Receiver operating characteristic curve analysis was used to calculate the area under the curve (AUC) and to compare the predictive performance of SI, RSI, MSI, and MSIGA.

Results: The study included 271 patients, of whom 102 required blood transfusion and 169 did not. The AUC for SI, RSI, MSI, and MSIGA were 0.732 (95% confidence interval [CI], 0.673-0.791), 0.732 (95% CI, 0.672-0.791), 0.785 (95% CI, 0.732-0.839), and 0.826 (95% CI, 0.778-0.874), respectively. MSIGA demonstrated superior performance in predicting the need for blood transfusion compared to traditional shock indices.

Conclusion: MSIGA may be a practical and effective tool to predict blood transfusion requirements in patients with PPH.