Usefulness of Shock Index and Delta Shock Index for Management of Postpartum Hemorrhage in Hypertensive Disorder in Pregnancy Cases

Abstract Background : Although the SI (Shock index; heart rate / systolic blood pressure) is a useful indicator in the management of PPH (postpartum hemorrhage), there are few reports of SI in pregnant women with complicated with HDP (hypertensive disorder in pregnancy) cases. HDP patients have a high systolic blood pressure and the bleeding volume may not be reflected in SI. The purpose of this study was to examine whether SI and ΔSI (peak SI−baseline SI) would be clinically useful indicators, and to detect the cut-off value for judging abnormal obstetric bleeding. Methods: Retrospective case-control study in 107 patients with HDP in an single perinatal medical center. The values ​​of prepartum SI, postpartum highest SI (peak SI), and the amount of bleeding until peak SI were retrospectively examined. The Kruskal-Wallis test was used to determine the relationship between peak SI, ΔSI and the amount of bleeding until peak SI. ROC(receiver operatorating characteristic) analysis was performed to determine the cut-off value. Results: Both peak SI and ΔSI were significantly related to the amount of bleeding up to peak SI (p <0.001). ROC analysis showed a cut-off values of peak SI where the amount of bleeding exceeded 500ml, 1,000ml, and 1,500ml. The values ​​are 0.77 (sensitivity 64%, specificity 84%; AUC 0.81), 0.76 (sensitivity 87%, specificity 69%; AUC 0.86), 0.99 (sensitivity 100%, specificity 91%; AUC 0.97). And ΔSI, respectively, were 0.25 (sensitivity 66.6%, specificity 88.7%; AUC 0.84), 0.31 (sensitivity 81%, specificity 87.9%; AUC 0.91), and 0.43 (sensitivity 100%, specificity 93.1%; AUC 0.98).Conclusion: In HDP cases, if the peak SI is greater than 0.99, similar to non-HDP pregnancies, or if the ΔSI is greater than 0.43, we need to recognize it as bleeding of 1,500ml or more. In addition, ΔSI may be a more sensitive and specific indicator than conventional peak SI in HDP cases.