Noninvasive Methods for Measurement of Intracranial Pressure in Patients with Acute Neurotrauma: A Systematic Review and Meta-Analysis

Invasive intracranial pressure (ICP) monitoring provides essential guidance for the treatment of patients with suspected head injuries; however, it remains incompatible with prehospital use. While several noninvasive ICP-measuring methods exist, previous studies have not adequately addressed their potential in a prehospital setting. In this systematic review and meta-analysis of diagnostic test accuracy, we explore the accuracy of existing noninvasive methods for ICP monitoring and assess their potential usefulness in prehospital screening for elevated ICP. This systematic review and meta-analysis were conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses guideline. Embase, Scopus, PubMed, CENTRAL, and Cochrane databases were sought for relevant articles on June 23, 2025. All studies evaluating minimally invasive and transportable methods for ICP assessment were included. Animal studies, <i>in vitro</i> studies, reviews, and meta-analyses were excluded. Study selection was performed by two independent reviewers, and conflicts were resolved by a third reviewer. Potential for prehospital use of each method was evaluated using four predetermined criteria. Summary receiver operator characteristic curves and summarized sensitivity and specificity were reported if multiple studies investigating the same method were eligible for meta-analysis. The applicability and risk of bias of the included studies were assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool for diagnostic test accuracy studies. Fifty-five articles were included. Ultrasound of optic nerve sheath diameter (ONSD) was the method with the highest potential for prehospital use. We found a summarized sensitivity of 92.6% (95% confidence interval [CI]: 87.0; 95.9%) and a summarized specificity of 85.1% (95% CI: 74.1; 92.0%) for detecting increased ICP through ONSD measurement. Other methods for diagnosing elevated ICP diagnosis showed poor diagnostic accuracy or low potential for prehospital use. We found ultrasound estimation of the ONSD to show the highest potential for prehospital use. Prospective studies are needed to verify their diagnostic capability in the prehospital setting.