Major obstetric haemorrhage: monitoring with thromboelastography, laboratory analyses or both?
Karlsson and colleagues nicely evaluate hemostasis in postpartum hemorrhage (PPH). They show that coagulopathy related to dilution and hemorrhagic consumption can be evaluated by the TEG (thrombelastography) in a fashion similar to standard laboratory tests in major obstetric hemorrhage (MOH; blood loss greater than 2000 mL), as compared with minor PPH (less than 600 mL). Furthermore, TEG and standard laboratory tests both correlate with blood loss.
Interestingly, the TEG, but not standard laboratory tests, demonstrates faster clot initiation, perhaps as a result of a physiologically increased clotting in MOH, but decreased clot strength which, in this group, could be related to dilution and inhibited function caused by the more extensive resuscitation strategy with fluids (crystalloids and colloids). Furthermore, the three different phases of cell-based hemostasis can be seen in that the R-time in TEG (initiation) correlates with the aPTT, the K & alpha angle in TEG (amplification) correlate with platelets, INR, aPTT and fibrinogen (amplification) and, lastly, the MA in TEG (propagation and clot strength) correlates in a non-specified manner with all the standard laboratory tests.
This study has several limitations: the lack of a standardized strategy for fluid resuscitation, for the administration of tranexamic acid and transfusions, the lack of standardized timing of samples, and the small sample size. Nevertheless, the TEG or the equivalent ROTEM (thromboelastometry) seem to provide a faster and more precise diagnosis of coagulopathy and could hence be advantageous for the evaluation and treatment of ongoing obstetric hemorrhage. However, the clinical impact should be tested in randomized controlled trials.
– Jakob Stensballe