Thromboelastography versus Standard Coagulation Assays in Patients with Postpartum Hemorrhage

Abstract

Objective Thromboelastography (TEG), a point-of-care test that measures blood's dynamic viscoelastic properties, is routinely used to guide resuscitation in surgical specialties with high hemorrhage risk. Patients with ongoing postpartum hemorrhage (PPH) often develop coagulopathy and hypofibrinogenemia. Timely assessment of fibrinogen is crucial because cryoprecipitate for repletion requires thawing time prior to administration. TEG may provide rapid assessment of coagulopathy in ongoing hemorrhage but this has not been thoroughly studied. Our objective was to determine if TEG accurately reflects coagulopathy in ongoing PPH when compared with standard assays. Study Design This was a retrospective cohort study of people with ongoing PPH (quantified blood loss >1,000 mL), from January 1, 2016, to December 31, 2019. TEG variables and standard coagulation parameters were compared in patients who had both assays drawn simultaneously. As a secondary analysis, patients who had TEG were compared with those who did not. The Mann–Whitney, Fisher's exact, Kruskal–Wallis, Spearman's rho, and logistic regression tests were used for analysis. Significance was set at p < 0.05. Results A total of 680 patients were included, 69 of whom had TEG and coagulation parameters drawn simultaneously and were included in the primary analysis. The remainder were included in the secondary analysis. TEG variables and coagulation assays correlated significantly—prolonged R with increased PTT (rho 0.25, p = 0.04), prolonged K and decreased α angle with decreased fibrinogen (rho −0.61, p < 0.001; rho 0.24, p < 0.001), and decreased maximum amplitude with decreased platelets (rho 0.62, p < 0.001). Those who had thromboelastographic assays had higher blood loss and need for interventions to manage hemorrhage than those who did not. Conclusion TEG correlated significantly with standard laboratory assays in ongoing PPH, including for patients with hypofibrinogenemia. Given the point-of-care nature and rapid turnaround time, TEG should be considered for timely hemorrhage evaluation and directed resuscitation of coagulopathy. Key Points