Assessment value of blood pressure variability combined with serum tau protein for the prognosis of patients with traumatic brain injury

Objective To investigate the prognostic value of blood pressure variability (BPV) combined with serum tau protein in patients with traumatic brain injury (TBI). Methods A total of 205 TBI patients were prospectively enrolled and categorized into mild, moderate, and severe groups based on their Glasgow Coma Scale (GCS) scores at admission. BPV [coefficient of variation for systolic and diastolic blood pressure (CV-SBP, CV-DBP)] and serum tau protein levels were measured. Their correlations with disease severity and 28-day prognosis were analyzed. Univariate and multivariable logistic regression analyses identified prognostic factors, and receiver operating characteristic (ROC) curves evaluated the predictive performance of individual indicators and their combination. Results Levels of CV-SBP, CV-DBP, and tau protein significantly increased with TBI severity (all p < 0.017) and showed positive correlations with the degree of injury (all p < 0.001). Multivariate analysis identified pupillary dilation, midline shift ≥5 mm, elevated CV-SBP, elevated CV-DBP, and elevated tau protein as independent risk factors for poor prognosis. The areas under the ROC curve (AUC) for predicting poor prognosis were 0.778 for CV-SBP, 0.765 for CV-DBP, 0.799 for tau protein, and 0.921 for the combination model. The combined model’s predictive efficacy was significantly superior to any single indicator alone (all p < 0.05). Conclusion Both BPV and serum tau protein are reliable predictors of severity and poor prognosis in TBI patients. Their combination demonstrates superior incremental predictive performance compared with any single indicator in this cohort, but requires external validation before clinical implementation.