Carotid artery velocity-time integral variation combined with passive leg raising test to predict hypotension after induction in older patients under general anesthesia: a prospective study.

BACKGROUND: Older patients are at an increased risk of developing hypotension following the induction of general anesthesia, which is linked to a higher incidence of postoperative complications, mortality, and morbidity. This study aimed to investigate the effectiveness of carotid velocity time integral variation (ΔcVTI) combined with the passive leg raising test (PLR) in predicting hypotension after anesthesia induction in elderly patients. METHODS: This prospective observational study enrolled 75 older patients (65–75 years, ASA II–III) undergoing elective surgery under general anesthesia. Carotid blood flow was continuously monitored using a wearable Doppler ultrasound patch, and ΔcVTI (%) was calculated during passive leg raising. Anesthesia was induced with etomidate, alfentanil, and rocuronium following a standardized protocol. Post-induction hypotension was defined as mean arterial pressure < 65 mmHg, a > 20% reduction from baseline, or systolic pressure < 90 mmHg within 3 min after induction. RESULTS: The incidence of hypotension observed in the study was 29 cases (39%). The area under the ROC curve for ΔcVTI in predicting hypotension after anesthesia induction was 0.84 (95% CI, 0.74 to 0.94; P < 0.001), with an optimal cutoff value of 13.6%, a sensitivity of 72.4% (95% CI, 54.3–85.3%), and a specificity of 97.8% (95% CI, 88.7–99.6%). Logistic regression analysis identified ΔcVTI as the sole independent risk factor for hypotension following anesthesia induction. CONCLUSIONS: ΔcVTI combined with the preoperative passive leg raising test may serve as a simple, non-invasive, and reliable method for predicting anesthetic hypotension in older patients. TRIAL REGISTRATION: Clinical Trial Registry on January 8, 2025. ( www.chictr.org.cn ; ChiCTR2500095534).