Significant reduction of red blood cell transfusion requirements by changing from a double-unit to a single-unit transfusion policy in patients receiving intensive chemotherapy or stem cell transplantation

Abstract

Background: Traditionally, single-unit red blood cell transfusions were believed to be insufficient to treat anemia, but recent data suggest that they may lead to a safe reduction of transfusion requirements. We tested this hypothesis by changing from a double- to a single-unit red blood cell transfusion policy.

Design and methods: We performed a retrospective cohort study in patients with hematologic malignancies receiving intensive chemotherapy or hematopoietic stem cell transplantation. The major end-points were the reduction in the total number of red blood cell units per therapy cycle and per day of aplasia. The study comprised 139 patients who received 272 therapy cycles. Overall 2212 red blood cell units were administered in 1548 transfusions.

Results: During the periods of the double- and single-unit policies, one red blood cell unit was transfused in 25% and 84% of the cases and the median number of red blood cell units per transfusion was two and one, respectively. Single-unit transfusion led to a 25% reduction of red blood cell usage per therapy cycle and 24% per aplasia day, but was not associated with a higher out-patient transfusion frequency. In multivariate analysis, single-unit transfusion resulted in a reduction of 2.7 red blood cell units per treatment cycle (P = 0.001). The pre-transfusion hemoglobin levels were lower during the single-unit period (median 61 g/L versus 64 g/L) and more transfusions were administered to patients with hemoglobin values of 60 gl/L or less (47% versus 26%). There was no evidence of more severe bleeding or more platelet transfusions during the single-unit period and the overall survival was similar in both cohorts.

Conclusions: Implementing a single-unit transfusion policy saves 25% of red blood cell units and, thereby, reduces the risks associated with allogeneic blood transfusions.

Figure 1.

Reduction of RBC units per therapy and transfusion-free time. The box plots display medians, interquartile ranges, and 95% confidence intervals. The double RBC-unit period is represented in light gray and the single-unit period in dark gray. (A) Changing the transfusion policy led to a 25% reduction of the transfused RBC units per therapy cycle (P=0.003). (B) Normalization to one aplasia day resulted in a 24% reduction of the RBC transfusions in the single-unit period (P<0.001). (C) The mean time between two transfusions was 20% longer in the double-unit period (P<0.001).

Figure 2.

Adherence to the transfusion policy. Adherence to the assigned RBC transfusion strategy was analyzed by calculating the percentage of correctly administered RBC transfusions in the two study periods. Light gray indicates one RBC unit, dark gray two, and black more than two RBC units per transfusion. Single units were transfused in 25% of the cases during the double-unit period and in 84% during the single-unit period.

Figure 3.

Overall survival according to the RBC transfusion policy. Kaplan-Meier survival estimates in patients during the double- and single-unit RBC periods. The 30- and 100-day survival probabilities were 98% (95%-confidence interval 96–99%) and 89% (84–94%) without differences between the two groups (P=0.893) indicating that the transfusion policy had no influence on overall survival.