Bedside Assessment of Coagulation in Post-partum Hemorrhage by Thromboelastography (TEG ®6S)

Postpartum hemorrhage (PPH) is one of the leading causes of maternal deaths. Its prognosis is directly influenced by the early diagnosis and treatment of the associated coagulopathy. In this context, fibrinogen concentration is the best predictor of a severe PPH. The medical interest of thromboelastography/elastometry to early detect and guide the rapid correction of coagulopathy in PPH is regularly discussed. The principal aim of this study is to evaluate the performance of a new hemostasis point of care device (thromboelastography - TEG ®6S) for the diagnosis of coagulopathy during PPH. A secondary aim will be to determine the normal values of TEG6S at the end of a normal pregnancy.

Postpartum hemorrhage (PPH) is a complication of 5 to 10% of deliveries and is the leading cause of maternal mortality, all over the world. In France, as in other developed countries, 20% of maternal mortality is related to PPH complications with a high rate of avoidance (85%) due to inappropriate or delayed therapeutic measures). The management of PPH is based on recommendations highlighting the need for early detection and treatment of coagulopathy, which is predictive of the hemorrhage severity. The prognosis of the PPH is directly related to the rapidity of the coagulopathy treatment (30 to 60 minutes after diagnosis). Severe PPH is often associated with clotting disorders of either primary origin (disseminated intravascular coagulation) or secondary origin (coagulation factors loss due to hemorrhage). A hypofibrinogenemia \< 2 g/L is the best predictor of a severe PPH with a positive predictive value of 100% . Similarly, abnormal coagulation tests appear to be predictive of the severity of the bleeding and the subsequent need for invasive procedures. The assessment of coagulation is currently based on standard laboratory hemostasis tests, but with delayed time to obtain results, generally greater than 60 minutes. Therefore, early and fast assessment of hemostasis during PPH is essential to estimate the bleeding severity and allow early and adequate administration of pro-coagulant products, leading to an improved prognosis of PPH. The medical interest of thromboelastography (TEG) to early diagnose and guide the treatment of a coagulopathy in PPH is regularly discussed. A previous observational study performed by our team in 2013 during PPH (95 patients and133 samples) compared the TEG 5000 parameters with the standard laboratory hemostasis tests. Our results confirm the good predictability of TEG 5000 for the early detection of a hypofibrinogenemia ≤ 2 g / l and/or thrombocytopenia ≤ 80 000 platelets / mm3 (AUC between 0.91 and 0.97). Among the biological parameters analyzed by the TEG 5000, the parameters K-MRTGG and FF-MRTGG (maximum rate of thrombus generation) were also evaluated. Their predictabilities were as good as the usual K-MA or FF-MA (comparable AUC) and were available more rapidly than usual parameters (3 ± 3 min for FF-MRTGG and 8 ± 3 min for K-MRTGG), allowing a very early evaluation of hemostasis. The aim of this prospective observational study is therefore to evaluate the performance of a new delocalized hemostasis monitoring device (thromboelastography - TEG ®6S) for the diagnosis of coagulopathy during PPH.