Cochrane Review: Platelet transfusions are used to prevent bleeding in people with low platelet counts due to treatment-induced bone marrow failure

Comparison of different platelet count thresholds to guide administration of prophylactic platelet transfusion for preventing bleeding in people with haematological disorders after myelosuppressive chemotherapy or stem cell transplantation - The Cochrane Library 


Findings from this review were based on three studies and 499 participants. Without further evidence, it is reasonable to continue with the current practice of administering prophylactic platelet transfusions using the standard trigger level (10 x 10⁹/L) in the absence of other risk factors for bleeding.

 

Plain language summary

Platelet transfusions are used to prevent bleeding in people with low platelet counts due to treatment-induced bone marrow failure

Review question
We evaluated the evidence about whether platelet transfusions given to prevent bleeding in people with lower platelet counts (for example 5 x 10⁹/L or below) were as effective and safe as the current standard (10 x 10⁹/L or below), or whether higher platelet count levels (20 x 10⁹/L or below, 30 x 10⁹/L or below, or 50 x 10⁹/L or below) were safer than the current standard (10 x 10⁹/L or below). Our target population was people with blood cancers (for example leukaemia, lymphoma, myeloma) who were receiving intensive (myelosuppressive) chemotherapy treatments or stem cell transplantation.
Background
People with blood cancers may have low platelet counts due to their underlying cancer. Blood cancers may be treated with chemotherapy and stem cell transplantation, and these treatments can cause low platelet counts. Platelet transfusions may be given to prevent bleeding when the platelet count falls below a prespecified threshold platelet count (for example 10 x 10⁹/L), or may be given to treat bleeding (such as a prolonged nosebleed or multiple bruises). Giving platelet transfusions at a lower prespecified threshold platelet count may increase the chance that bleeding will occur, which may be harmful, whereas giving platelet transfusions at a higher prespecified threshold platelet count may mean that people receive unnecessary platelet transfusions. Platelet transfusions can have adverse effects and have cost and resource implications for health services, so unnecessary transfusions should be avoided.
Study characteristics
The evidence is current to July 2015. We found no new studies in this update of the review. This review identified three randomised controlled trials that compared giving platelet transfusions to prevent bleeding when the platelet count is 10 x 10⁹/L (the current standard) or below versus giving platelet transfusions to prevent bleeding at higher platelet count levels (20 x 10⁹/L or below or 30 x 10⁹/L or below). None of the studies compared a lower trigger or alternative trigger to the current standard. These trials were conducted between 1991 and 2001 and included 499 participants. Two trials included adults with leukaemia who were receiving chemotherapy. One trial included children and adults receiving a stem cell transplant.
Two of the three studies reported sources of funding. Neither of the studies that reported funding sources were industry sponsored.
Key results
Giving platelet transfusions to people with low platelet counts due to blood cancers or their treatment to prevent bleeding when the platelet count was 10 x 10⁹/L or below did not increase the risk of bleeding compared to giving a platelet transfusion at higher platelet counts (20 x 10⁹/L or below or 30 x 10⁹/L or below).
Giving platelet transfusions to prevent bleeding only when the platelet count was 10 x 10⁹/L or below resulted in a reduction in the number of platelets given. We found no evidence to demonstrate that giving a platelet transfusion when the platelet count was 10 x 10⁹/L or below decreased the number of transfusion reactions compared to giving platelet transfusions at higher platelet counts (20 x 10⁹/L or below or 30 x 10⁹/L or below).
None of the three studies reported any quality of life outcomes.
Findings from this review were based on three studies and 499 participants. Without further evidence, it is reasonable to continue using platelet transfusions to prevent bleeding based on the current standard transfusion threshold (10 x 10⁹/L).
Quality of the evidence
The evidence for most of the findings was of low quality. This was because participants and their doctors knew which study arm the participant had been allocated to, and also the estimate of the treatment effect was imprecise.