Liberal Transfusion Strategy Associated With Fewer Unfavorable Neurological Outcomes in TBI

Patients with traumatic brain injury (TBI) and anemia who received red blood cell transfusions at a higher hemoglobin threshold may have lower rates of unfavorable neurological outcomes at 180 days compared with those who were managed with a restrictive threshold, according to a prespecified secondary analysis of the TRAIN randomized clinical trial published in JAMA Network Open. The authors cautioned that the finding is uncertain and does not establish the optimal transfusion threshold for patients with TBI.

The analysis included 475 patients with moderate to severe TBI and hemoglobin levels below 9 g/dL. Patients were randomized to a liberal transfusion strategy with a threshold below 9 g/dL or a restrictive strategy with a threshold below 7 g/dL. At 180 days, 58.5% of patients in the liberal group had an unfavorable neurological outcome, compared with 67.4% in the restrictive group, an absolute difference of about 9 percentage points (RR, 0.86; 95% CI, 0.75-1.00; P = .047). Patients in the liberal group received a median of two red blood cell units, compared with zero in the restrictive group.

The researchers found no significant differences in 28-day mortality or serious adverse events, including infection and cerebral ischemia. After adjustment for established prognostic variables, the liberal strategy remained associated with a lower probability of unfavorable neurological outcome (OR, 0.60; 95% CI, 0.38-0.94; P = .03).

The authors emphasized several limitations, including that the TBI subgroup was not independently powered and the primary analysis had a fragility index of 1. A per-protocol analysis also did not confirm the intention-to-treat finding. An individual patient-data meta-analysis combining the TRAIN and HEMOTION trials is underway.