The previous threshold used for administering prophylactic platelet transfusion in patients with AML receiving chemotherapy was 20,000 per µL.
The platelet level associated with spontaneous hemorrhage in a stable patient with no other hemorrhagic risk factors is 5,000 per µL. The threshold for prophylactic transfusion was raised to 10,000 per µL because:
(1) some automated analyzers may not be accurate at low platelet counts
(2) platelet products may not always be readily available, so a safety margin is helpful.
If a patient had one or more risk factors for bleeding, then a threshold of 20,000 per µL was used. These conditions included:
(1) fever > 38°C
(2) active bleeding
(3) invasive procedure contemplated
Other authors also included (Gmur et al, Wandt et al):
(4) coagulation disorder or DIC
(5) receiving heparin therapy
(6) white blood cell count > 50,000 per µL
(7) acute promyelocytic leukemia
(8) receiving drugs affecting platelet function
Using a lower threshold for prophylactic platelet transfusion reduced transfusions by 21.5% with no significant impact on outcomes.
