Role of transcranial Doppler pulsatility index for predicting neurological deterioration in mild-to-moderate traumatic brain injury patients in intensive care unit

ABSTRACT Background: Traumatic brain injury (TBI) is a leading cause of death and long-term disability worldwide, particularly among young adults in low- and middle-income countries. Even patients presenting with mild-to-moderate TBI may experience secondary neurological deterioration due to evolving intracranial pathology. Early identification of patients at risk remains challenging. Transcranial Doppler (TCD) ultrasonography provides a noninvasive bedside assessment of cerebral hemodynamics, and the pulsatility index (PI) reflects downstream cerebrovascular resistance and intracranial compliance. Methods: This prospective observational study included 100 adult patients with mild-to-moderate TBI admitted to a tertiary care intensive care unit (ICU). Demographic data, mechanism of injury, clinical status, and computed tomography (CT) findings were recorded. TCD examination was performed at admission to measure middle cerebral artery velocities and calculate PI. Patients were followed for seven days. Neurological deterioration was defined as a decrease in Glasgow Coma Scale score by ≥2 points, requirement of mechanical ventilation, or need for neurosurgical intervention. Receiver operating characteristic (ROC) curve analysis and multivariate logistic regression were used to assess the predictive value of PI. Results: Neurological deterioration occurred in 22% of patients. Admission PI was significantly higher in patients who deteriorated compared with those who remained stable (1.35 ± 0.18 vs. 1.14 ± 0.17; P < 0.001). ROC analysis demonstrated that PI predicted neurological deterioration with an area under the curve of 0.82 (95% confidence interval (CI): 0.73–0.91). A PI cutoff value of ≥1.25 yielded a sensitivity of 77% and a specificity of 80%. On multivariate analysis, admission PI ≥1.25 independently predicted neurological deterioration (adjusted OR 4.3; 95% CI 1.7–10.8). Conclusion: Admission PI measured by TCD is a reliable, noninvasive predictor of early neurological deterioration in patients with mild-to-moderate TBI and may aid early risk stratification in the ICU.