3.5 Blood component transfusion

3.5.3 Platelet count and prophylactic platelet transfusion in patients undergoing chemotherapy and haematopoietic stem cell transplantation

Evidence Statements for Chemotherapy and haematopoietic stem cell transplantation
Evidence Statements –
chemotherapy and haematopoietic stem cell transplantation
Evidence Consistency Clinical impact Generalisability Applicability
ES5.9 In patients undergoing chemotherapy and haematopoietic stem cell transplantation – in relation to the effect on mortality – the difference between a prophylactic platelet transfusion trigger of <10 x 109/L without risk factors or <20 x 109/L plus risk factors versus a higher trigger is uncertain. The effect at lower values is unknown. X
ES5.10 In patients undergoing chemotherapy and haematopoietic stem cell transplantation – in relation to major bleeding events – there is no difference between a prophylactic platelet transfusion trigger of <10 x 109/L without risk factors or <20 x 109/L plus risk factors and a higher trigger. The effect at lower values is unknown. X
ES5.11 In patients undergoing chemotherapy and haematopoietic stem cell transplantation – in relation to RBC transfusion – there is no difference between a prophylactic platelet transfusion trigger of <10 x 109/L without risk factors or <20 x 109/L plus risk factors and a higher trigger. The effect at lower values is unknown. X

ES, evidence statement

=A; =B; X=D; (see Table 2.1)

Recommendation – chemotherapy and haematopoietic stem cell transplantation
R8

Grade B

In patients undergoing chemotherapy and haematopoietic stem cell transplantation, the recommended strategy for prophylactic use of platelets is transfusion at a platelet count of <10 x 109/L in the absence of risk factors, and at <20 x 109/L in the presence of risk factors (e.g. fever, minor bleeding).
Practice Point – chemotherapy and haematopoietic stem cell transplantation
PP22

In patients undergoing chemotherapy and haematopoietic stem cell transplantation, there is no evidence to support:

  • a lower trigger for prophylactic platelet transfusion for patients with risk factors (e.g. fever, minor bleeding)
  • a strategy of therapeutic-only platelet transfusions (i.e. for treatment of clinically significant bleeding).

Further research to determine the safety and efficacy of a lower platelet transfusion trigger is underway.

PP, practice point; R, recommendation

The use of prophylactic platelet transfusions in patients receiving myelosuppressive chemotherapy or undergoing allogeneic haematopoietic stem cell transplantation (HSCT) is significant. It currently accounts for most of the platelet concentrate usage in Australia. In this clinical setting – in the absence of acute bleeding or the need for an invasive procedure – prophylactic platelet transfusion is usually guided by platelet counts.

The review examined studies concerning platelet count and bleeding risk, together with the intervention of platelet transfusion, but excluded studies in perioperative or acute bleeding settings.

The review identified four RCTs (Level II) comparing different platelet transfusion triggers. Three studies147-149 compared a platelet transfusion trigger of 10 x 109/L with one of 20 x 109/L. Another study used 30 x 109/L as the higher trigger.150 Of these studies, three147,149,150 did not demonstrate a significant difference in mortality between the two study arms. These three studies reported bleeding events, but none observed a significant difference in bleeding rates between the two study arms, nor in bleeding rates in relation to a more restrictive platelet transfusion trigger. RBC transfusion rates were reported in all four studies. None of the studies demonstrated significant differences in number of RBC units transfused, or in the number of transfusions, between study arms.

Based on these results, in patients undergoing myelosuppressive chemotherapy or HSCT, the recommended strategy for prophylactic platelet transfusion is at a platelet count of <10 x 109/L in the absence of risk factors, and at <20 x 109/L in the presence of risk factors (see recommendation R8 above).

There is no evidence at this time to support a lower threshold for prophylaxis, or for the absence of prophylaxis. However, these questions are the current focus of two major international RCTs.