Blood transfusions in the emergency department: A descriptive analysis and referral patterns at a non-trauma center

Anemia is a prevalent condition associated with significant healthcare burden, contributing to approximately 800,000 Emergency Department (ED) visits annually in the United States. While immediate management often relies on packed red blood cell (PRBC) transfusions, limited data exist on the populations receiving transfusions in the ED, especially outside traumatic indications. This study aims to characterize patients receiving PRBC transfusions in the ED, with particular focus on the role of outpatient referrals and potential differences among subgroups based on clinical presentation and outcomes.

A retrospective cohort study was conducted at an academic quaternary care hospital (which is not a trauma center) over a 12-month period. ED encounters involving the transfusion of at least one unit of PRBC were identified through blood bank records in the Electronic Medical Record (EMR) system. Data extracted included patient demographics, chief complaints, pre-transfusion hemoglobin levels, referral sources, discharge diagnoses, and outcomes. Patients referred to the ED for low hemoglobin levels were classified as either symptomatic or asymptomatic based on reported symptoms or clinical findings. Descriptive statistics, linear ANOVA, chi-square tests, and Kaplan-Meier survival analysis were used to assess differences in outcomes, including admission rates and 30-month mortality.

The cohort included 558 ED encounters, representing 462 unique patients. The median age of the cohort was 68 years (interquartile range: 55-76), with 50.8 % male patients. The overall hospital admission rate was 84.2 %. A substantial proportion (55.3 %) of encounters were referrals from outpatient providers, with 63.1 % of these referrals due to abnormal laboratory results. Notably, 21.5 % of these referrals were asymptomatic. Of 558 total encounters, 52 were referred to the ED for abnormally low hemoglobin but ultimately discharged. The mean pre-transfusion hemoglobin level was 6.5 g/dL (SD 1.3), with a significantly higher level in patients who were discharged (6.8 g/dL vs. 6.5 g/dL for admitted patients, p < 0.001). Hemorrhage was more common in admitted patients (88.6 % vs. 11.4 % in discharged patients), and 37 % of the cohort died within 30 months, with 40 % of deaths occurring within the first month after the ED encounter.

These findings highlight the significant burden of outpatient referrals for anemia in an ED setting, representing over half of all encounters, often for asymptomatic patients or those who were clinically stable. While most patients were admitted, a considerable proportion of those referred from outpatient settings were discharged, suggesting that some ED referrals may be preventable. The study underscores the need for refined referral processes, including optimizing access to outpatient transfusion services and considering alternative management strategies for stable anemic patients, such as iron therapy. Developing multidisciplinary protocols could reduce unnecessary ED visits and associated healthcare costs, ultimately improving patient care and system efficiency. Future research should focus on prospective data to better understand the factors driving ED referrals for anemia and evaluate interventions aimed at improving referral workflows and reducing the need for transfusion in stable patients.