Platelet Transfusions

Abstract

Clinical experience indicates that uncomplicated bleeding due to severe thrombocytopenia can be effectively treated with platelet transfusions. The decision to transfuse platelets should be reached on an individual basis. Prophylactic transfusion may be indicated when substantial bleeding can be anticipated, as in surgical candidates with thrombocytopenia owing to marrow insufficiency or in subjects given massive chemotherapy. Platelet transfusions in patients with idiopathic thrombocytopenic purpura are of doubtful value. Very large doses of fresh platelets are needed. Fresh whole blood should be given to anemic or hypo-volemic patients; otherwise, platelet-rich plasma (PRP) or platelet concentrate (PC) should be used. At present, the concentrate derived from 4-8 units of blood is recommended for a 30-kg child, about twice this amount for a 70-kg adult, to be administered every 2 or 3 days. The required dose of PRP is about 1/2 as large. The increment in the recipient''s platelet count roughly indicates the effectiveness of the transfusion. Platelet transfusions should be restricted to severely thrombocytopenic patients for specific indications, since there is the usual risk of hepatitis. No other severe reactions were observed. Decreased responsiveness resulting from platelet antibodies is uncommon except after 50-100 transfusions. If possible, the transfused PRP or PC should be compatible with respect to ABO and Rh red cells antigens. The need for large amounts of platelets cannot be adequately filled by plateletpheresis. Sufficient amounts of platelets will become available only with increased routine processing of blood for component therapy. In view of the rapid loss of viability in present platelet preparations, widespread use of platelet transfusions must await improved methods of platelet preservation through freezing.