Cid, J., & Lozano, M. (2007). Lower or higher doses for prophylactic platelet transfusions: Results of a meta-analysis of randomized controlled trials. Transfusion, 47, 464–470.

INCLUSION CRITERIA:

• Looked at randomized controlled trials (RCTs) reported through December 2005
• Treatment groups included adult patients (older than age 16 years) receiving high-dose transfused platelets (HDPs) and adult patients receiving a lower dose of transfused platelets (LDPs).
• Reported data included
  • Mean difference in the transfusion interval
  • Mean difference in the post-transfusion platelet (PLT) count increment
  • Odds ratio (OR) of bleeding in the HDP group versus the LDP group.

EXCLUSION CRITERIA: Children were excluded.

• FINAL NUMBER STUDIES INCLUDED = 5
• SAMPLE RANGE ACROSS STUDIES: 46–120
• KEY SAMPLE CHARACTERISTICS: The proportion of male patients ranged from 37%–60%. The median age was 38–55 years. Chemotherapy-induced thrombocytopenia was included in all five trials. Three trials included patients with acute leukemia and undergoing bone marrow transplantation (BMT). One trial only included patients who underwent BMT. One trial included patients with acute leukemia and breast cancer. The total number of platelet transfusions administered ranged from 96–311. Platelets were collected by apheresis in four trials and by apheresis and whole blood donation in one trial. 

HDP groups showed a longer transfusion interval compared to the LDP group (p < 0.00001). Four studies with available data showed a significant increase in the transfusion interval when a high PLT dose was transfused. All transfused platelets were less than 24 hours old in one study and less than 72 hours old in another study. In two studies, the median number of days in which platelets were transfused was 3.71 and 2.3, respectively. In four of five trials, a significant increase in the post-transfusion PLT count increment was observed in the HDP group compared to the LDP group (p < 0.01). A significant increase in the proportion of bleeding patients was observed in the HDP group versus the LDP group. However monitoring of patients for bleeding varied, and methodologic challenges were encountered when analyzing the bleeding data. In addition, two of three trials were designed to analyze the efficacy of the transfusion of an HDP or an LDP; the presence of hemorrhage was a secondary endpoint. Only one trial was designed to look at the transfusion of lower-dose PLT in terms of safety. Outcomes only were available in three trials. No significant difference was observed in the OR of bleeding in the HDP or LDP group.  

Two trials are being conducted that the authors hope will provide information to clearly define the optimal dose of PLTs to transfuse prophylactically in patients with thrombocytopenia.