Diagnostic performance of serial bedside Capillary Hemoglobin, Lactate and Shock index for severe postpartum hemorrhage. A Prospective Cohort Study.

Objective: : To evaluate the diagnostic capacity of bedside capillary lactate (CLact), capillary Hemoglobin (CHb), and Shock index (SI) for severe postpartum haemorrhage (SPPH), at diagnosis 15 minutes and 30 minutes post-diagnosis Design: A prospective cohort study. Setting: A reference hospital in San Luis Potosi Mexico from February 2020 to March 2021 Population: Sixty women in vaginal labour or c-section who presented bleeding ≥500ml Methods: : SI, CLact, and CHb concentration were analyzed at diagnosis, 15 minutes, and 30 minutes time intervals. T-test or Wilcox test was used to compare the group of severe vs non-severe. A Receiver Operating Curve was done to determine their cut points, Sensitivity, specificity, and performance Main Outcome Measures: SPPH defined as bleeding ≥2000ml measured by gravimetric method. Results: SI at the diagnosis was significantly differentiate between severe from non-severe group (0.70 + 0.20 vs 0.90 + 0.38 P-value 0.0228) with al cut-point of 1.17 AUC of 0.76 sensitivity of 0.43 and specificity of 0.98. A capillary lactate measurement at 30 minutes was also significantly different between the groups (4.0 +1.90 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. Capillary haemoglobin was not able to significantly differentiate the groups Conclusions: : Shock index is an early sign of severe haemorrhage; Capillary lactate can significantly identify severe haemorrhage after 30 min. Capillary haemoglobin is not an early detector of severe haemorrhage.