Managing the coagulopathy of postpartum hemorrhage: an evolving role for viscoelastic hemostatic assays

Postpartum hemorrhage (PPH) is usually caused by obstetrical complications but may be exacerbated by hemostatic impairment. Standard laboratory tests of coagulation often take too long to become available to inform treatment in a rapidly changing clinical situation. The role of point-of-care viscoelastic hemostatic assays (VHAs) in monitoring hemostatic impairment and guiding procoagulant blood product replace-ment during PPH is evolving, although these technologies are not available in most maternity units. We have used VHAs during PPH in our institution for the last 8 years and have developed a simple algorithm to direct blood component replacement. VHAs are useful for reassuring clinicians that hemostasis is adequate and that procoagulant blood products are not required and an obstetrical cause for bleeding needs to be sought. VHAs can be used to detect hypofibrinogenemia due to dilution or acute obstetrical coagulopathy and to guide fibrinogen replacement. The role of VHAs in guiding fresh frozen plasma infusion is less clear, but normal results suggest that fresh frozen plasma is not required. In this review, we describe 3 cases of postpartum hemorrhage to illustrate different hemostatic scenarios and discuss the controversies and evidence gaps related to each case.