Preoperative corrected carotid flow time is associated with spinal anesthesia-induced hypotension in hypertensive patients: A prospective observational study.

BACKGROUND

Spinal anesthesia-induced hypotension (SAIH) is common in hypertensive patients, yet reliable preoperative markers remain limited. Corrected carotid flow time (CCFT) is a Doppler-derived index influenced by preload and ventricular ejection timing, but its association with SAIH in this population has not been established.

OBJECTIVE

To evaluate whether preoperative CCFT is independently associated with SAIH in hypertensive patients undergoing spinal anesthesia.

DESIGN

Single-center prospective observational study.

PATIENTS: In total, 110 hypertensive adults scheduled for lower abdominal or lower extremity surgery under spinal anesthesia.

SETTING

University hospital, operating room.

INTERVENTIONS: Preoperative carotid and brachial ultrasound assessments (CCFT, carotid intima-media thickness (CIMT), flow-mediated dilation (FMD), carotid blood flow, and internal jugular vein collapsibility index) were performed. Hemodynamics were recorded for 30 min after spinal injection.

MAIN OUTCOME MEASURES: Primary outcome: SAIH (≥20% decrease in systolic blood pressure or SBP <90 mmHg sustained for ≥1 minute).

SECONDARY OUTCOMES: hemodynamic trends and discriminative performance of ultrasound parameters.

RESULTS

SAIH occurred in 54 patients (49.1%). CCFT was shorter in patients who developed hypotension (326.5 ± 71.3 vs 437.3 ± 82.9 ms, p < 0.001). In the primary multivariable model including CIMT, FMD, and beta-blocker use, CCFT remained independently associated with SAIH (adjusted odds ratio 0.980 per 1-ms increase, 95% confidence interval (CI) 0.973-0.988, p < 0.001). CCFT alone had an area under the curve (AUC) of 0.854 (95% CI 0.785-0.924); the 358.5-ms cut-off had 74.1% sensitivity and 87.5% specificity. A clinical model including age, baseline SBP, and beta-blocker use had an AUC of 0.572 (95% CI 0.465-0.679); adding CCFT increased the AUC to 0.866 (95% CI 0.799-0.932; paired comparison p < 0.001).

CONCLUSIONS

Preoperative CCFT was independently associated with SAIH and improved discrimination when added to a parsimonious clinical model. The cohort-derived threshold requires external validation before clinical implementation.

TRIAL REGISTRATION: ClinicalTrials.gov (https://clinicaltrials.gov/), NCT06749184.