Transfusions and long-term functional outcomes in traumatic brain injury

In this paper, the authors' goal was to examine the relationship between transfusion and long-term functional outcomes in moderately anemic patients (lowest hematocrit [HCT] level 21-30%) with traumatic brain injury (TBI). While evidence suggests that transfusions are associated with poor hospital outcomes, no study has examined transfusions and long-term functional outcomes in this population. The preferred transfusion threshold remains controversial.

The authors performed a retrospective review of patients who were admitted with TBI between September 2005 and November 2007, extracting data such as HCT level, status of red blood cell transfusion, admission Glasgow Coma Scale (GCS) score, serum glucose, and length of hospital stay. Outcome measures assessed at 6 months were Glasgow Outcome Scale-Extended score, Functional Status Examination score, and patient death. A multivariate generalized linear model controlling for confounding variables was used to assess the association between transfusion and outcome.

During the study period, 292 patients were identified, and 139 (47.6%) met the criteria for moderate anemia. Roughly half (54.7%) underwent transfusions. Univariate analyses showed significant correlations between outcome score and patient age, admission GCS score, head Abbreviated Injury Scale score, number of days with an HCT level < 30%, highest glucose level, number of days with a glucose level > 200 mg/dl, length of hospital stay, number of patients receiving a transfusion, and transfusion volume. In multivariate analysis, admission GCS score, receiving a transfusion, and transfusion volume were the only variables associated with outcome (F = 2.458, p = 0.007; F = 11.694, p = 0.001; and F = 1.991, p = 0.020, respectively). There was no association between transfusion and death.

Transfusions may contribute to poor long-term functional outcomes in anemic patients with TBI. Transfusion strategies should be aimed at patients with symptomatic anemia or physiological compromise, and transfusion volume should be minimized.