Blood Product Transfusion Patterns in One Lithuanian and Two Polish Academic Emergency Departments: A Retrospective...

Background and Objectives: Blood product transfusion is an important emergency intervention for patients with acute bleeding, severe symptomatic anemia, and selected hematological conditions. Patterns of ED transfusion may differ according to the local case mix, referral pathways, and blood bank processes. We compared transfusion-related characteristics and outcomes among patients treated in one Lithuanian and two Polish academic emergency departments. Materials and Methods: We performed a retrospective comparative study of adults (aged ≥18 years) in whom a blood product transfusion was initiated in the ED between 1 January 2022 and 31 December 2024 at one Lithuanian and two Polish academic hospitals. We compared patient characteristics, indication categories, shock index values, time to transfusion, blood product use, adjunctive therapies, laboratory values, ED disposition, hospital length of stay, and in-hospital mortality. Findings are reported as center-cohort comparisons and are not intended to represent national practice. Results: A total of 670 patients were included: 367 at the Lithuanian center and 303 across the two Polish centers. GI bleeding was significantly more common in the Lithuanian center cohort (48.8% vs. 22.8%; OR 3.22 [95% CI 2.30-4.53]; p < 0.001), whereas anemia and malignancy-related anemia were more frequent in the Polish center cohort (anemia: 34.7% vs. 18.3%, OR 0.42 [95% CI 0.29-0.6]; p < 0.001; cancer: 26.4% vs. 7.6%, OR 0.23 [95% CI 0.15-0.37]; p < 0.001). The median shock index was significantly higher in the Lithuanian center cohort than in the Polish center cohort (0.9; [IQR 0.7-1.2] vs. 0.7; IQR 0.6-0.9; 0.2 [95% CI 0.1-0.3]; p < 0.001), and pre-transfusion hemoglobin was lower (64.5 g/L [IQR 50-86] vs. 119 g/L [IQR 83-139]; p < 0.001). Uncrossmatched RBC units were more frequently administered in the Lithuanian center cohort (133 (36.9%) vs. 47 (15.6%); OR 3.18 [95% CI 2.18-4.64]; p < 0.001), as was fresh frozen plasma (71 (19.5%) vs. 3 (1%); OR 24.23 [95% CI 7.55-77.8]; p < 0.001). Conversely, platelet transfusions were more common in the Polish center cohort (17 (4.6%) vs. 45 (14.9%), OR 0.28 [95% CI 0.16-0.5]; p < 0.001). The median time from ED arrival to transfusion was longer in the Lithuanian center cohort than in the Polish center cohort (150 [IQR 75-256] vs. 117 [IQR 103-154], 23 [95% CI 9-39]; p = 0.002). Hospital admission was significantly more frequent in the Lithuanian cohort than in the Polish cohort (350 (95.4%) vs. 112 (37.0%); p < 0.001). Among admitted patients, the median hospital length of stay was significantly longer in the Lithuanian cohort compared with the Polish cohort (6 days [IQR 3-11] vs. 1 day [IQR 1-5]; 95% CI for the difference 3-4; p < 0.001). In-hospital mortality was 33.5% (n = 123) in the Lithuanian cohort and 13.9% (n = 42) in the Polish cohort (OR 3.13 [95% CI 2.12-4.63]; p < 0.001). Conclusions: Among transfused patients in the three participating academic EDs, the case mix, blood product use, transfusion timing, and unadjusted outcomes differed substantially. These center-specific findings may inform future prospective studies of how referral pathways, clinical populations, and local transfusion processes influence ED blood product utilization. They do not establish differences in national practice, transfusion appropriateness, or causal effects on clinical outcomes.