SUMMARY: Platelets are often transfused preemptively to reduce the risk for spontaneous bleeding in patients who are thrombocytopenic following chemotherapy or hematopoietic stem cell transplantation. In the United States, a little over 2 million platelet units are transfused annually. The risks associated with platelet transfusion such as febrile and allergic reactions, Transfusion Related Acute Lung Injury and infections, have to be taken into consideration before transfusion is planned. Further, unlike other blood products, platelets must be stored at room temperature and this limits the platelet unit shelf life to only 5 days, to prevent the risk for bacterial growth during storage. This in turn is an additional burden to the hospital blood banks. The AABB (American Association of Blood Banks) commissioned and funded the development of platelet transfusion guidelines with the help of 21 experts from various specialties of medicine, after a systematic review of 17 randomized controlled trials and 53 observational studies. A platelet unit in this guideline refers to 1 apheresis platelet unit or a pool of 4-6 whole blood derived platelet concentrates, containing approximately 3- 4 x 1011 platelets. Thrombocytopenia refers to a platelet count below the lower limit of the normal range used by the laboratory performing the count. Six recommendations were made for 4 different clinical settings.
Hospitalized Adult Patients with Therapy-Induced Hypoproliferative Thrombocytopenia
Recommendation 1: The AABB recommends that platelets should be transfused prophylactically to reduce the risk for spontaneous bleeding in hospitalized adult patients with therapy-induced hypoproliferative thrombocytopenia. The AABB recommends transfusing hospitalized adult patients with a platelet count of 10 × 109 cells/L or less to reduce the risk for spontaneous bleeding. The AABB recommends transfusing up to a single apheresis unit or equivalent. Greater doses are not more effective, and lower doses equal to one half of a standard apheresis unit are equally effective.
Adult Patients Having Minor Invasive Procedures
Recommendation 2: The AABB suggests prophylactic platelet transfusion for patients having elective central venous catheter placement with a platelet count less than 20 × 109 cells/L.
Recommendation 3: The AABB suggests prophylactic platelet transfusion for patients having elective diagnostic lumbar puncture with a platelet count less than 50 × 109 cells/L.
Adult Patients Having Major Elective Non-neuraxial Surgery
Recommendation 4: The AABB suggests prophylactic platelet transfusion for patients having major elective non-neuraxial surgery with a platelet count less than 50 × 109 cells/L.
Recommendation 5: The AABB recommends against routine prophylactic platelet transfusion for patients who are non-thrombocytopenic and have cardiac surgery with cardiopulmonary bypass. The AABB suggests platelet transfusion for patients having bypass who exhibit perioperative bleeding with thrombocytopenia and/or evidence of platelet dysfunction.
Adult Patients Receiving Antiplatelet Therapy Who Have Intracranial Hemorrhage (Traumatic or Spontaneous)
Recommendation 6: The AABB cannot recommend for or against platelet transfusion for patients receiving antiplatelet therapy who have intracranial hemorrhage (traumatic or spontaneous).
The authors acknowledge that the platelet transfusion threshold recommendations made by the various medical specialty societies, may be different, but the evidence based recommendations provided herein, will complement clinical judgment, as individualized decisions are made, to transfuse platelets. Kaufman RM, Djulbegovic B, Gernsheimer T, et al. Ann Intern Med. 2015;162:205-213.
