Association Between Intracranial Pressure Variability and Clinical Outcomes in Acute Brain Injury: A Systematic Review and Meta-Analysis

Acute brain injury (ABI) is a major cause of mortality and disability. Although intracranial pressure (ICP) monitoring traditionally relies on static thresholds, ICP variability (ICPV) may provide additional prognostic insight. This study aims to evaluate the association between short- and long-term ICPV and clinical outcomes in patients with ABI. Embase, Web of Science, Medline, Scopus, CENTRAL, and PubMed were searched from inception to August 29, 2025; the protocol was registered in PROSPERO (CRD420251116221) on July 30, 2025. Prospective and retrospective studies assessing ICPV and clinical outcomes in adult (18 y or older) patients with ABI were included. Two reviewers independently performed screening and data extraction. Random-effects meta-analyses were conducted separately for short-term and long-term ICPV effect estimates, risk of bias was assessed using ROBINS-E. Ten studies comprising 3243 patients with ABI were included. Higher short-term ICPV was associated with significantly reduced odds of poor clinical outcome in adjusted (aOR=0.58, 95% CI: 0.41-0.81; P<0.005) and crude analyses (OR=0.65, 95% CI: 0.55-0.78; P<0.005). Long-term ICPV showed no statistically significant association with poor outcome in adjusted (aOR=1.29, 95% CI: 0.84-1.96; P=0.24) or crude analyses (OR=1.47, 95% CI: 0.68-3.19; P=0.33). Overall, short-term ICPV was associated with favorable clinical outcomes, whereas long-term ICPV demonstrated no significant association. Further research using standardized ICPV metrics is needed to clarify its prognostic role in neurocritical care.