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.