Diagnostic Performance of Serial bedside Capillary Lactate, Hemoglobin, and Shock Index for Severe Postpartum

Objective: To assess the diagnostic capacity of bedside capillary lactate (CLact), capillary Haemoglobin (CHb), and shock index (SI) for severe postpartum haemorrhage (SPPH > 2000 ml) at diagnosis, 15 minutes and 30 minutes later. Method: A cohort study was carried out in a reference hospital in San Luis Potosi, Mexico from February 2020 to March 2021, and included sixty women in vaginal labor or c-section who presented PPH (≥500 ml in labor or ≥1000 ml in c-section) measured by the gravimetric method. CLact, SI, and CHb concentrations were analyzed at diagnosis of PPH, 15 minutes, and 30 minutes. Patients who presented total blood loss of >2000 ml were considered SPPH. A T-test or Wilcox test was performed to compare the groups of non-severe and severe. Sensitivity, specificity, and performance were calculated by A Receiver Operating Curve. Results: A CLact measurement at 30 minutes was significantly different between the non-severe and severe groups (4.0 + 1.9 vs 4.8 + 1.15 P-value 0.001, with an optimal cut point of 4.3 mmol/dl at AUC 0.75, sensitivity 0.85, and specificity of 0.62. With a cut-point of 1.17, an AUC of 0.76, sensitivity of 0.43, and specificity of 0.98, SI at diagnosis was significantly different between the non-severe and severe groups (0.70 + 0.20 vs. 0.90 + 0.38 P-value 0.0228). Conclusion: SI is an early sign of SPPH;CLact can significantly identify SPPH after 30 minutes.