Introduction: Recombinant activated factor VII (rFVIIa) is a potent anticoagulant, active at sites of tissue damage with expression of the tissue factor. The use of rFVIIa results in occupation of most tissue factor molecules. Initiation of the extinsic pathway leads in turn to activation of maximum quantities of factor X with subsequent massive generation of thrombin. At the same time, factor IX of the intrinsic pathway is also activated and consequently, procoagulation activity increases. The use of supra-normaltherapeutic doses of rFVIIa is currently suggested for management of lifethreating bleeding refractory to both surgical intervention and conventional pharmacotherapy.
Method: Experience gained with administration of 90 μg kg−1 rFVIIa in 7 cardiac surgery patients (5 valve operations, 2 coronary artery bypass grafting) is presented. The patients were given rFVIIa postoperatively for bleeding, which was considered as continuous and intractable (e.g. in 2 cases total blood loss 2450 mL and 3200 mL, respectively, in another patient bleeding 1000 mL within 1.5 h after triple re-exploration). Five patients underwent surgical revision before rFVIIa administration, frequently repeated. Before the use of rFVIIa, all of the other haemotherapeutic and pharmacological strategies (blood derivatives including apheresis platelets, factors II, VII, IX and X, antithrombin III) were attemped, based on laboratory results.
Results: Administration of rFVIIa was associated with significant reduction in blood loss; no other haemostatic agents were instituted afterwards. Median blood loss was 630 mL [465-765] [25-75 percentile] over 4 hours prior to administration of rFVIIa and 120mL [105-165] over 4 hours after administration of rFVIIa (P < 0.05, Paired Wilcoxon test). None of the patients needed additional re-operation.
Discussion: The use of rFVIIa proved highly effective in the management of massive postoperative haemorrhage. No clinical signs of general hypercoagulation were noticed, although laboratory tests showed shortening of coagulation times, mainly of prothrombin time expressed as INR (1.19 ± 0.1 vs. 0.82 ± 0.2).
1 Hendriks HG, van der Maaten JM, de Wolf J, et al. An effective treatment of severe intractable bleeding after valve repair by one single dose of activated recombinant factor VII. Anesth Analg
2 Dietrich W, Spannagl M. Caveat against the use of activated recombinant factor VII for intractable bleeding in cardiac surgery. Anesth Analg