Usually there is no need to treat thrombocytopenia with platelet transfusions, as patients with HIT rarely bleed spontaneously. Indeed, platelet transfusions should be avoided because the transfused platelets can be activated by the same immune mechanisms as the patient's own platelets. Anecdotal experience describes throm-botic events soon after platelet transfusions given to patients with acute HIT (Babcock et al., 1976; Cimo et al., 1979). Several consensus conferences (Contreras, 1998; Hirsh et al., 2001; British Committee for Standards in Haematology, 2003; Warkentin and Greinacher, 2004) stated that thrombotic thrombocytopenic purpura (TTP) and HIT are two disorders in which prophylactic platelet transfusions are not recommended because of the risk of precipitating thrombosis.
Recommendation. Prophylactic platelet transfusions are relatively contraindicated in patients with acute HIT (grade 2C).
Therapeutic platelet transfusions are appropriate for patients with HIT who develop severe hemorrhage, particularly if the heparin administration has been discontinued for more than a day.
Was this article helpful?