Noninvasive intracranial pressure waveform metrics: from correlation to clinical impact

Abstract Noninvasive intracranial pressure (ICP) monitoring remains an important yet unmet need in neurocritical care. The study by de Moraes et al. provides valuable evidence demonstrating a strong correlation between invasive ICP measurements and noninvasive waveform-derived pulse shape index (PSI), including in patients with altered skull integrity following craniectomy. These findings represent a meaningful step forward in validating waveform-based noninvasive ICP assessment. However, despite consistency with prior studies reporting PSI outliers and higher values in craniectomy patients, the clinical utility of PSI remains uncertain. It is currently unclear whether PSI can reliably guide therapeutic interventions, enhance prognostication, or improve decision-making beyond conventional ICP metrics. Moreover, variability in PSI across heterogeneous patient populations driven by factors such as age, surgical status, and underlying neurological pathology raises concerns regarding generalizability and clinical implementation. Additional barriers include operator dependence, calibration variability, limited integration with multimodal neuromonitoring, and unresolved questions regarding cost-effectiveness. While combining noninvasive waveform metrics with adjunctive tools such as pupillometry or optic nerve sheath diameter assessment may enhance clinical relevance, standardized protocols and multicenter validation are required. Future research should focus on outcome-based validation and clinical integration to ensure that advances in noninvasive ICP waveform analysis translate into meaningful improvements in patient care.