Latent class phenotypes and emergency department disposition for patients with traumatic subdural hematoma and midline shift

Guidelines recommend surgical evacuation for traumatic subdural hematoma (SDH) with >5 mm midline shift (MLS), but emergency department (ED) triage varies between the operating room (OR) and the intensive care unit (ICU). We investigated whether ED disposition to the OR versus ICU was associated with differences in outcomes and whether distinct patient phenotypes modified these associations.

We retrospectively identified adult patients from the ACS TQIP dataset with traumatic SDH, MLS >5 mm, and ED disposition to either the ICU or OR. We defined patient phenotypes using latent class analysis (LCA) and investigated associations between ED disposition and outcomes (inpatient mortality, favorable discharge) using risk-adjusted hierarchical logistic regression. We tested for interaction between patient phenotype and ED disposition and repeated these analyses among patients undergoing an ICU stay ≥1 day and cranial surgery.

Among 9582 patients, 29% (N = 2794) were triaged to the OR. Two LCA-informed phenotypes emerged: class 1 (older-mild injury) and class 2 (younger-severe injury). There was an interaction between ED disposition and patient phenotype, such that younger-severe patients had lower mortality with OR triage (P < 0.001). In the subgroup of 4573 patients (48%) with ≥1 day of ICU stay who underwent cranial surgery, there was a significant interaction between OR triage and the older-mild phenotype indicating increased mortality (P = 0.003).

For traumatic SDH with MLS >5 mm, triage the OR was associated with improved outcomes only among younger, severely-injured patients, while older, mildly-injured patients may benefit from early ICU stabilization. These findings support phenotype-guided ED triage strategies to optimize outcomes.