(574) Grade 3 DAI in TBI Does Not Predict Need for Tracheostomy, Gastrostomy, or Discharge Outcome

Introduction: Diffuse Axonal Injury (DAI) on MRI, graded by topographic severity from Grade 1 to 3, is a common finding in traumatic brain injury (TBI). The relationship between DAI severity and need for tracheostomy (trach) and percutaneous endoscopic gastrostomy (PEG) in TBI is unknown. We compare the rates of trach/PEG and ICU discharge outcomes in severe TBI (sTBI) patients with DAI-3 vs. no DAI/DAI 1-2.

Methods: This is a retrospective cohort study (10/2022- 6/2023) of the UCI Neurology TBI & Concussion Program Database, including all standardized consultations for sTBI at a tertiary Level 1 Trauma Center (consult criteria: severe TBI (GCS < 8), invasive neuromonitoring, complex TBI per SICU). DAI grade was extracted from radiology report and confirmed by authors. Patients without an MRI brain were excluded.

Results: A total of 30 patients met inclusion criteria with 40% found to have DAI-3 on MRI. There was no demographic difference in patients with or without MRI. DAI-3 patients had significantly lower median admit GCS (4 [IQR 5-13] vs 7 [3-8], p= 0.031) versus non-DAI-3. There were no significant differences in rate of trach & PEG (43% vs 37%, p=0.754) or PEG tube alone (14 % vs 6 %) between survivors with DAI-3 vs non-DAI-3. We found no significant difference in mortality (41% vs. 11%, p= 0.13), median discharge GCS (12.5 [IQR 9-14 vs 12 [9.5-14], p=0.78]), length of stay (15.5 days [IQR 11- 27] vs 18.0 [IQR 9-29] p=0.94), neurosurgical rate (41% vs 50%, p = 0.12), or discharge location to skilled nursing facility (33% facility vs 55%, p= 0.26) between DAI-3 vs. non-DAI-3, respectively.

Conclusions: DAI grade 3 compared to no DAI/grade 1-2 does not predict higher likelihood of obtaining a trach or PEG during hospitalization or worse outcome with regard to mortality, GCS, length of stay, or disposition location. This preliminary study suggests DAI grade should not be used in isolation for prognostication. Future studies will focus on assessing subgroups such as those greater than 65 years old, mechanism of injury, and individual burden of TBI to help improve prognostication for TBI patients.