High-dose tranexamic acid for treating postpartum haemorrhage after vaginal delivery.
This report describes 60 women given high-dose tranexamic acid (4 g) if they sustained >800 mL blood loss, compared with a historical cohort of 99 patients. There was no difference in blood loss, duration of bleeding or transfusion. The transfusion protocol and triggers for blood products is not described. The authors also mention a French Periodic Safety Update report noting a high rate of unexplained renal failure after severe PPH treated tranexamic acid, among other drugs. The authors conclude that the potential harm of high-dose tranexamic acid outweighs its benefit for treating postpartum haemorrhage.
Certainly, the literature from surgical patients would support this conclusion in that there appears to be no efficacy in giving doses of tranexamic acid >2 g, as the drug shows a plateau effect in efficacy as one would expect with a competitive inhibitor. We really do need the results of the WOMAN study to inform management of postpartum haemorrhage, for the primary outcome is reducing death and hysterectomy and may not show a reduction in blood loss. In the CRASH-2 study, tranexamic acid saved lives but did not reduce blood usage, probably because the survivors who would have died without tranexamic acid needed blood. One needs to remember that our aim in treating patients is to reduce mortality and that reducing bleeding is not a surrogate marker for reducing death.
– Beverley J. Hunt