Utilization of platelet transfusions in the intensive care unit: indications, transfusion triggers, and platelet count responses.
BACKGROUND
A description of current platelet (PLT) transfusion practice in the intensive care unit (ICU) is needed.


METHODS
All thrombocytopenic patients (PLT count, <150 x 10(9)/L) who received PLT transfusions were identified from a previous prospective study of consecutive medical-surgical ICU patients; trauma, orthopedic, and cardiac surgery were exclusions. Risk factors for ineffective transfusions were examined.


RESULTS
Of 261 ICU patients, 118 (45.2%) had thrombocytopenia and a PLT count nadir of less than 50 x 10(9) per L (n = 22), 50 to 99 x 10(9) per L (n = 37), and 100 to 149 x 10(9) per L (n = 59). Twenty-seven (22.9%) patients received PLT transfusions (n = 76 transfusions) and 37 (31.4%) had major bleeding. PLT dose was approximately 3 to 4 x 10(11) per L transfusion. Therapeutic (n = 24) and prophylactic (n = 52) PLT transfusion triggers were 51 x 10(9) per L (interquartile range [IQR], 26 to 68) and 41 x 10(9) per L (IQR, 20 to 57), respectively, as measured at a median of 4.5 hours (IQR, <1.6 to 6.9) before transfusion. A single PLT transfusion resulted in a median PLT increase of 14 x 10(9) per L (IQR, -2 to 30) measured at 5.2 hours (IQR, 1.8 to 8.8) after the transfusion; however, no PLT count increase was observed after 17 transfusions given to 13 (48.1%) patients. No risk factors for ineffective transfusions were identified.


CONCLUSIONS
Among critically ill patients, most PLT transfusions were administered to prevent, rather than to treat, bleeding, with a transfusion trigger of 40 to 50 x 10(9) per L. Nearly half of ICU patients who received transfusions failed to mount a PLT count increase after a single transfusion. Prospective studies are needed to determine the effects of PLT transfusions on bleeding and predictors of ineffective transfusions in the ICU.
Arnold
Donald M
DM
Department of Medicine, McMaster University, Hamilton, Ontario, Canada. arnolddm@mcmaster.ca
Crowther
Mark A
MA
Cook
Richard J
RJ
Sigouin
Christopher
C
Heddle
Nancy M
NM
Molnar
Laura
L
Cook
Deborah J
DJ
D000368:Aged; D016638:Critical Illness; D005260:Female; D006470:Hemorrhage / Q000097:blood / Q000209:etiology; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D010976:Platelet Count; D017713:Platelet Transfusion / Q000009:adverse effects; D020127:Recovery of Function; D012189:Retrospective Studies; D012307:Risk Factors; D013921:Thrombocytopenia / Q000628:therapy*