LAUSR

Amniotic fluid embolism (AFE) causes consumption coagulopathy, which requires a massive transfusion to save the mother's life. The preparation of such a massive transfusion is too time‐consuming in extremely emergent clinical settings and occasionally leads to devastating side effects such as transfusion‐associated acute lung injury. C1 esterase inhibitor (C1INH) is a protein with the ability to inhibit complement, coagulation and kinin pathways. The C1INH concentration in AFE patients is low, and it has been speculated that the administration of C1INH concentrate could have a striking and beneficial effect on AFE patients in critical condition by ameliorating their perturbed coagulation system. We report the case of a 32‐year‐old Japanese AFE patient in whom deteriorated vital signs and coagulopathy recovered within minutes after an injection of C1INH concentrate. C1INH concentrate can quickly revive the deteriorated vital signs and the atonic uterus that stem from AFE and may reduce the total amount of transfusion.