Value of transcranial color-coded duplex sonography-derived middle cerebral artery pulsatility index in intracranial pressure assessment at moderate to high altitudes

To assess transcranial color-coded duplex sonography (TCCD) as a reliable method for predicting intracranial pressure (ICP) in brain injury patients at moderate-to-high-altitude, clinical data were collected from patients admitted to the Intensive Care Unit of a tertiary hospital on the Qinghai-Tibet Plateau between April 24 and July 24, 2025. A total of 158 sets of middle cerebral artery pulsatility index (MCA-PI) and ICP data from 54 patients were included. The median PI, ICP, and arterial carbon dioxide partial pressure (PaCO₂) were 1.19 (0.99, 1.42), 15.08 (13.61, 17.10) mmHg, and 36.00 (33.00, 40.13) mmHg, respectively. Spearman's analysis showed a strongly positive PI-ICP correlation (r = 0.769, P < 0.001). The generalized estimating equation (GEE) for non-invasive intracranial pressure (nICP) prediction based on MCA-PI was established as: nICP = 4.46 × PI + 9.62. For PI > 1.21 predicting ICP > 15 mmHg, sensitivity, specificity, and ROC AUC were 0.850, 0.936, and 0.916 (95% CI: 0.868-0.963, P < 0.001), respectively. MCA-PI correlates with ICP and aids in identifying elevated ICP; this non-invasive, low-cost method is suitable for moderate-to-high altitude areas.