Structural Versus Physiologic Drivers of Surgical Escalation, Critical Care Utilization, and Disposition in Isolated Traumatic Brain Injury

Background In traumatic brain injury (TBI), radiographic thresholds guide surgical decisions, while physiologic criteria determine intracranial pressure (ICP) monitoring. Whether these same features predict critical care needs and post-acute discharge outcomes remains uncertain. We studied lesion-specific and size-dependent factors that influence neurosurgical escalation, intensive care unit (ICU) length of stay, and discharge pathways in adults with isolated blunt TBI without skull fracture. Methods We performed a retrospective cohort study using the American College of Surgeons Trauma Quality Improvement Program Participant Use File (2017–2022). Adults aged ≥ 15 years with isolated blunt TBI and no skull fracture or moderate-to-severe extracranial injury (AIS > 1 in non-head regions) were included. Lesions were classified by AIS-derived morphology and a modified Berne–Norwood framework. Multivariable logistic regression estimated adjusted odds ratios (ORs) for craniotomy, ICP monitoring, and discharge to rehabilitation or hospice. Multivariable linear regression assessed predictors of ICU length of stay, adjusting for demographics, injury severity, system-level factors, and comorbidities. Results Among 451,754 patients, isolated subarachnoid hemorrhage (35.0%) and subdural hematoma (SDH) ≤ 8 mm (30.8%) were most common. Large SDH (> 8 mm) was strongly linked to craniotomy (OR 5.44, 95% CI 5.26–5.62) and ICP monitoring (OR 2.04, 95% CI 1.95–2.14). Diffuse axonal injury (DAI) was inversely related to craniotomy (OR 0.20, 95% CI 0.15–0.26) but positively related to ICP monitoring (OR 1.50, 95% CI 1.34–1.68). DAI predicted longer ICU stays (β + 4.08 days, 95% CI 2.82–5.33), while large contusions (> 2 cm) were linked to discharge to hospice (OR 1.55, 95% CI 1.15–2.10; all values p < 0.01). Conclusions In isolated blunt TBI, focal, size-dependent lesions influence surgical decisions, while diffuse injury patterns impact extended ICU stays and recovery or end-of-life choices. Lesion characteristics enable early assessment of surgical needs, resource requirements, and post-acute care strategies, supporting lesion-specific neurocritical care planning.