Haemostatic monitoring during postpartum haemorrhage and implications for management

Abstract

SummaryPostpartum haemorrhage (PPH) is a major risk factor for maternal morbidity and mortality. PPH has numerous causative factors, which makes its occurrence and severity difficult to predict. Underlying haemostatic imbalances such as consumptive and dilutional coagulopathies may develop during PPH, and can exacerbate bleeding and lead to progression to severe PPH. Monitoring coagulation status in patients with PPH may be crucial for effective haemostatic management, goal-directed therapy, and improved outcomes. However, current PPH management guidelines do not account for the altered baseline coagulation status observed in pregnant patients, and the appropriate transfusion triggers to use in PPH are unknown, due to a lack of high-quality studies specific to this area. In this review, we consider the evidence for the use of standard laboratory-based coagulation tests and point-of-care viscoelastic coagulation monitoring in PPH. Many laboratory-based tests are unsuitable for emergency use due to their long turnaround times, so have limited value for the management of PPH. Emerging evidence suggests that viscoelastic monitoring, using thrombelastography- or thromboelastometry-based tests, may be useful for rapid assessment and for guiding haemostatic therapy during PPH. However, further studies are needed to define the ranges of reference values that should be considered ‘normal’ in this setting. Improving awareness of the correct application and interpretation of viscoelastic coagulation monitoring techniques may be critical in realizing their emergency diagnostic potential.

Fibrin-based clot formation as an early and rapid biomarker for progression of postpartum hemorrhage: a prospective study

“…19 Fibtem performed on the Rotem machine (Tem International, Munich, Germany) measures fibrin-based clot strength in blood after platelet inhibition. The maximum clot firmness (MCF) measures clot strength and correlates moderately with laboratory fibrinogen during PPH.…”

Haemostatic management of obstetric haemorrhage

“…These are clinical observation combined with empirical, formulaic blood product replacement; and either laboratory-based PT/ aPPT ratios and Clauss fibrinogen or point-of-care (POC) testing [12,18]. Routine coagulation tests are the most common method for monitoring haemostasis during PPH, with the advantage of well-regulated quality control [12,18].…”

“…These changes result in shorter prothrombin and activated partial thromboplastin times (PT/aPTT), sometimes below the normal laboratory range, and a large increase in thrombo-elastographic parameters such as maximum clot firmness (MCF) and maximum amplitude (MA) [17][18][19][20][21]. Natural anticoagulants such as protein S fall, contributing to the prothrombotic state [22], and there is an increase in fibrinolysis, especially in the uterus at the time of placental separation [23,24].…”

Point of Care Testing and Transfusion Safety in Resource Limited Settings: A Review

“…Out of these the viscoelastometric POCT devices are particularly useful in giving quick information on all the main phases and components of clot formation, including fibrinogen concentration, platelet activity and fibrinolysis [38]. For this reason they are utilized to guide the clinical management of acute coagulopathy that follows trauma and hemorrhages, including obstetric cases [39][40][41]. To our knowledge however there are no studies that document the utilization or the appropriateness of POC coagulation tests in resource-limited settings.…”