Monitoring of hemostatic status in four patients being treated with recombinant factor VIIa.

Recombinant Factor VIIa (rVIIa) is a potent hemostatic agent for the management of refractory bleeding in patients with Factor VII deficiency or Factor VIII inhibitors. While the current recommended dose is usually effective, the most appropriate dose remains a subject of debate. Since factor VII levels and shortening of the pro-thrombin time do not appear to correlate with response, an appropriate laboratory marker of clinical response has not been identified.

Effects of recombinant factor VIIa on platelet function and clot structure in blood with deficient prothrombin conversion.

While recombinant factor VIIa (rFVIIa) shows promise as a broad-spectrum hemostatic agent, questions remain regarding the most appropriate dose and the best way to monitor its effects. In this study we tested the sensitivity of a thrombin dependent platelet assay, platelet contractile force, to the effects of rFVIIa in normal, factor-deficient, and inhibitor-containing blood samples. Dose dependent effects of rFVIIa on platelet contractile force (PCF) and clot elastic modulus (CEM) were measured in all blood samples.

Successful use of recombinant factor VIIa for hemostasis during total knee replacement in a severe hemophiliac with high-titer factor VIII inhibitor.

A 32-year-old male patient with severe factor VIII (FVIII) deficiency had developed a high-titer FVIII inhibitor at age 13. Recurrent hemarthroses caused bony destruction in both knees, significantly impairing his ability to walk. Knee examination revealed 20 degrees of varus, destruction of the medial joint line, and flexion contracture.