To the Editor:--The Task Force on Blood Component Therapy of the American Society of Anesthesiologists is to be congratulated on the recent publication of “Practice Guidelines for Blood Component Therapy.”Unfortunately, recommendations concerning the use of cryoprecipitate in patients with von Willebrand's disease fail to incorporate recent evidence demonstrating the greater efficacy and safety of virally inactivated factor VIII concentrates in this setting.
Von Willebrand's disease represents the most common of the inherited bleeding disorders, with a prevalence as great as 1% of the population. Subtypes of this disease are characterized by quantitative and/or qualitative abnormalities of von Willebrand factor, a plasma protein essential to platelet adhesion and the stabilization of factor VIII. Although DDAVP (desmopressin acetate) provides effective therapy in some patients with von Willebrand's disease, the response is unpredictable, frequently limited, and contraindicated in certain subtypes of the disease. Selection of the most appropriate therapy requires identification of the specific subtype of von Willebrand's disease present.
Administration of cryoprecipitate has been the traditional approach to management of bleeding in the patient with von Willebrand's disease unresponsive to DDAVP; however, more recent evidence demonstrates that select factor VIII concentrates provide a more efficacious and safe source for replacement of von Willebrand factor. Both the United Kingdom Regional Haemophilia Centre Directors and the Association of Hemophilia Clinic Directors of Canada have recommended the administration of virally inactivated factor VIII concentrates in preference to cryoprecipitate in the management of patients with von Willebrand's disease. [3,4]In comparison with other factor VIII concentrates, Humate-P (Armour Pharmaceutical, Kankakee, IL) contains the highest concentrations of von Willebrand factor antigen and activity and has been recommended as the treatment of choice in managing patients with von Willebrand's disease unresponsive to DDAVP. [5,6]The virally inactivated factor VIII concentrate Humate-P offers a safer, more efficacious approach than cryoprecipitate to management of the patient with von Willebrand's disease unresponsive to DDAVP. We suggest that the “ASA Practice Guidelines for Blood Component Therapy” be modified to incorporate recommendations concerning this recent advancement in the management of patients with von Willebrand's disease.
Thomas F. Slaughter, MD; Assistant Professor of Anesthesiology, Duke University and the Durham Veterans' Affairs Medical Center, Box 3094 DUMC.
Charles S. Greenberg, MD; Associate Professor, Division of Hematology/Department of Medicine, Duke University Medical Center, Box 3001 DUMC, Duke University Medical Center, Durham, North Carolina 27710.
(Accepted for publication May 2, 1996.)