Shock index and vital-sign reference ranges during the immediate postpartum period

Objective: To determine reference ranges for patient vital signs during the immediate postpartum period. Methods: A retrospective chart review collected data on the variables of interest for all women with 0-24-hour postpartum data available at two hospitals in the USA, between July 1, 2012, and January 31, 2015. Patients were excluded if they had received antihypertensives, uterotonics, or blood products. Regression lines, with 95% prediction intervals, were constructed for shock index, systolic blood pressure, heart rate, pulse pressure, and rate over pressure evaluation (ROPE) values. Results: There were 8874 patients and 87 336 data measurements included in the analysis. During the 24 hours following delivery, an increase in ROPE values, and decreases in pulse pressure, heart rate, and systolic blood pressure were recorded for all patients; an increase in shock index was observed among patients who had cesarean deliveries. Anomalous values for the shock index (>1.0), and reference ranges for pulse pressure (21.09-69.32 mm Hg), ROPE (1.01-3.22 bpm/mm Hg), heart rate (51-112 bpm), and SBP (81-137 mm Hg) were generated. Conclusion: Specific reference ranges for patients during the postpartum period could be used in future studies to determine the parameters, or combinations of parameters, that perform best as early markers of hemodynamic compromise in women experiencing early postpartum hemorrhage.