Background: To investigate factors associated with change of post-transfusion hemoglobin level, and to derive an equation that predicts post-transfusion changes in hemoglobin levels in hemodynamically stable anemic patients who visited emergency department.
Methods: A retrospective medical record review of patients who were hemodynamically stable and transfused with packed red blood cells was undertaken. Patients were randomly divided into two groups. One group (derivation group, 70% of total patients) was analyzed for factors associated with changes in post-transfusion hemoglobin levels, and linear regression analysis was performed to derive a prediction equation. The derived prediction equation was then externally validated with the other group (validation group, 30% of total patients).
Results: A total of 196 patients were enrolled. The 137 patients (70% of total patients) in the derivation group were analyzed for factors associated with changes in post-transfusion hemoglobin. Of those, body surface area and initial hemoglobin level were significantly correlated with changes in post-transfusion hemoglobin levels (p < 0.05). From these variables, linear regression analysis resulted in a prediction equation. The derived equation was validated externally with the 59 patients (30% of total patients) in the validation group and found to have an excellent correlation (r = 0.73, intraclass correlation = 0.84, p < 0.05).
Conclusions: Post-transfusion hemoglobin level in hemodynamically stable adult patients was associated with initial hemoglobin levels and body surface area. These factors must be considered when transfusing hemodynamically stable adult patients with anemia.