Four Distinct Dynamic Intracranial Pressure Trajectories and Their Prognostic Implications in Acute Brain Injury: A Multicenter Cohort Study

BACKGROUND: Acute brain injury (ABI) often elevates intracranial pressure (ICP), yet static measurements miss dynamic risk. We evaluated the prognostic value of early ICP trajectories. METHODS: We formed a multicenter ICU cohort from MIMIC-IV (2008-2022), eICU (2014-2015), and NSICU (2024-2025). Latent class growth modeling identified ICP trajectories over the first 120 h. Associations with in-hospital mortality were tested with Cox models, and incremental value beyond baseline clinical variables was quantified by AUC, integrated discrimination improvement (IDI), and net reclassification improvement (NRI). Sensitivity analyses were performed across datasets and age groups. RESULTS: Among 1700 patients with ABI, four trajectories emerged-Severe Progressive, Stabilized Elevated, Mildly Elevated Stable, and Normal. Versus Normal, mortality risk was highest for Severe Progressive (HR 13.54; 95% CI 9.35-19.59), followed by Stabilized Elevated (HR 2.53; 1.83-3.49) and Mildly Elevated Stable (HR 1.48; 1.16-1.91). In patients aged ≥ 55 years, risk with Stabilized Elevated was amplified (HR 2.87; 1.97-4.20). Adding trajectories improved risk stratification (IDI +0.065; NRI +0.201) with modest AUC gains. CONCLUSIONS: Early ICP trajectories define reproducible phenotypes with distinct mortality risk. Incorporating trajectories-particularly the stabilized-elevated pattern in older adults-adds prognostic value beyond clinical variables and supports prospective validation.