Patient characteristics and clinical determinants of outpatient red cell transfusions

There is a knowledge gap in the outpatient transfusion practice of red blood cells (RBC) according to optimal trigger, dose, and interval as well as which patients are in need of outpatient transfusion.

This single-center retrospective analysis investigates RBC transfusion practices in 804 patients with 5591 visits.

Blood disorders and solid tumors were the primary indications for transfusion, accounting for 82% of RBC use. Median (interquartile range) pretransfusion hemoglobin (Hb) level was 7.5 (6.9;8.1)g/dL. Linear regression models revealed that Hb increased by 1.04 g/dL per unit transfused and identified the concomitant transfusion of platelets, male sex, higher height, weight, and lower pre-transfusion Hb level as negative factors for the increase in Hb. Factors that correlate with Hb decline after transfusion include lower reticulocytes, male sex, height, and concomitant platelet transfusion. A longer interval to next transfusion was associated with higher reticulocyte counts, higher pre-transfusion Hb levels and number of units transfused. According to our models, the potential for reducing the use of RBC through single-unit transfusions decreases with increasing height, concomitant platelet transfusions, and lower pretransfusion Hb levels and is going along with a shorter interval to next transfusion. Nonsevere adverse reactions occurred in ≤0.24% of transfusions.

These results highlighted the effect of patient age, sex, Hb, height, and weight on outpatient RBC transfusion. These variables have to be considered in clinical practice and trials evaluating patient outcomes.