Efficacy and Safety of Single- Versus Double-Unit Red Blood Cell Transfusion in Trauma Patients With Asymptomatic Anemia.

Introduction Optimal packed red blood cell (PRBC) transfusion strategies for stable, non-bleeding anemic trauma patients remain controversial. The goal of this study was to examine the need for repeat transfusion following a single-unit (one unit) or double-unit (two units) transfusion strategy in trauma patients with asymptomatic anemia. Methods A single-site retrospective study at a level 1 trauma center was conducted in trauma patients with asymptomatic anemia requiring transfusion during index admission. Patient characteristics, admission vital signs, lab values, total PRBC transfusions, and operative interventions were recorded. Outcomes, including the need for additional transfusions beyond the initial anemia transfusion, changes in hemoglobin/hematocrit levels, hospital length of stay (LOS), ICU LOS, and total number of PRBC units transfused, were collected. Multivariable logistic regression was then performed to determine the impact of transfusion strategy on the need for subsequent transfusion. Results A total of 344 patients were identified: 114 received a double-unit PRBC, and 230 received a single-unit PRBC for asymptomatic anemia. The double-unit transfusion group received more blood transfusions than the single-unit group (4 vs. 3 units, p = 0.005). However, the need for additional transfusions did not differ between groups (42% vs. 39%, p = 0.6). Multivariable logistic regression identified only post-transfusion operative intervention as an independent predictor of repeat transfusion with an adjusted odds ratio (95% CI) of 6.55 (3.99, 10.76; p < 0.001). After adjusting for post-transfusion operation, most recent hemoglobin, and admission Glasgow Coma Scale score, the initial transfusion strategy did not significantly affect the need for repeat transfusion, with an adjusted odds ratio (95% CI) of 0.93 (0.54, 1.59; p = 0.786). Conclusions Restrictive, single-unit transfusion strategies appear safe and effective in stable, non-bleeding trauma patients. A single-unit transfusion strategy did not increase the likelihood for the need for repeat transfusions. These findings suggest that higher initial transfusion doses may unnecessarily increase blood product exposure without improving clinical outcomes.