Characteristics and in-hospital outcomes of patients presenting to a level 1 trauma center classified under the modified Brain Injury Guidelines.

Objective: The Brain Injury Guidelines (BIG) were modified in 2020 to improve efficiency and safety in triage decision-making. The aim of this study was to present characteristics and in-hospital outcomes of patients classified under category 1 of the modified BIG (mBIG 1).

Methods: A retrospective review of patients presenting with acute traumatic brain injury (TBI) to a level 1 trauma center between 2019 and 2023 was performed. Patients meeting clinical and radiographic criteria for mBIG 1 were identified. An additional cohort of patients was identified who were taking 81 mg of aspirin once daily (ASA81) before the hospital, but who otherwise met mBIG 1 criteria. Summary statistics and univariate analyses were performed.

Results: Three hundred three patients were identified and classified as mBIG 1. The mean patient age was 54.45 (SD 1.17) years and 41.3% were female. There were 144 patients (47.5%) who transferred from an outside hospital. The median admission Glasgow Coma Scale score was 15 (interquartile range [IQR] 15-15). Patients underwent an average of 2.28 (SD 0.03) CT scans. There were 123 (40.6%), 18 (5.9%), and 126 (41.6%) patients with subdural hematoma, intraparenchymal hemorrhage, and subarachnoid hemorrhage, respectively, with 36 patients (11.9%) presenting with multiple hemorrhages. Eleven patients (3.6%) experienced hemorrhage progression. No patient underwent neurosurgical intervention. The mean Injury Severity Score was 13.12 (SD 7.04). The median hospital length of stay (LOS) was 1.01 (IQR 0.37-4.56) days, 75.2% of patients were discharged home, 24.1% were discharged to rehabilitation, and 0.7% died in the hospital. An additional 25 patients were identified who were taking ASA81 prehospital, but otherwise met mBIG 1 criteria. None of these patients underwent neurosurgical intervention and there were no in-hospital deaths. One patient (4.0%) taking ASA81 experienced progression of their hemorrhage but still met mBIG 1 criteria. When compared to the mBIG 1 cohort, the aspirin cohort was significantly older (p < 0.001), but otherwise showed no differences in demographic, clinical, or radiographic variables. The combined mBIG 1 + aspirin cohort was stratified by hemorrhage progression (n = 12). Hospital LOS was significantly greater in the progression cohort (p = 0.017) and fewer patients were discharged home (p = 0.001). There was no difference in age, hypertension, admission mean arterial pressure, platelet count, international normalized ratio, partial thromboplastin time, hemorrhage pattern, and aspirin use between the groups.

Conclusions: Hemorrhage progression was rare, including cases in which patients were receiving prehospital low-dose aspirin therapy. More data are needed that evaluate the role of low-dose aspirin in the triage of patients with mild TBI.