Association Between Relative Anemia and Early Functional Recovery After Severe Traumatic Brain Injury (TBI)

Severe traumatic brain injury is associated with a multi-systemic response and changes in metabolic demand. Patients requiring intracranial pressure monitoring or cerebrospinal fluid diversion, often signifies a greater severity of injury. For this group, the association between RBC transfusion, transfusion thresholds, and clinical recovery is unknown. In this study, we studied the association between transfusion and clinical recovery for severe traumatic brain injury patients requiring external ventricular drain or intracranial pressure monitor placement.

Eighty-nine patients with a primary diagnosis of traumatic brain injury requiring implantation of either an intracranial pressure monitor or external ventricular drainage device were identified. All patients were managed in a Level 1 Trauma facility by board-certified neuro-intensive care practitioners for the course of their intensive care unit duration. The correlation between transfusion and clinical recovery, defined by change in Glasgow Coma Scale was assessed.

Thirty-four patients required surgical decompression, and 56.18 % of the cumulative cohort were transfused during admission. Overall, transfusion was not associated with significant clinical recovery (change in GCS > 3) for Hgb threshold of 7 mg/dL (<3, 29.03 vs. ≥3, 37.93 %; p = 0.49), nor for higher stratifications (8 mg/dL, p = 0.63; 9 mg/dL, p = 0.79, 10 mg/dL, p = 1). For patients who required transfusions at thresholds ≥8 mg/dL, there was a positive association with decreased length of hospitalization, [p = 0.01; <8 mg/dL: 22 (12-33), ≥8 mg/dL: 14 (7.75-20)] [median (IQR)]. Similarly, length of ICU stay was shorter for patients transfused at thresholds ≥9 mg/dL, (p = 0.02).

From our studies, we demonstrate no significant clinical benefit associated with stratified transfusion goals; however, there was a decrease in length of hospitalization for patients with transfusion thresholds of Hgb ≥ 8 mg/dL. Larger, randomized controlled trials may be required to more accurately assess outcomes in this patient population. In patients admitted for primary severe traumatic brain injury, we demonstrate no significant clinical benefit associated with stratified transfusion goals; however, there was a noticeable decrease in length of hospitalization for patients with transfusion thresholds of Hgb ≥ 8 mg/dL. Larger, randomized controlled trials may be required to more accurately assess outcomes in this patient population.