The corrected carotid artery flow time and carotid peak velocity variation do not predict spinal anesthesia-induced hypotension: A prospective observational study.

Abstract

Study objectiveA common side effect of spinal anesthesia is spinal anesthesia-induced hypotension (SAIH). The preoperative prediction of SAIH may prevent hypotension-related complications. Carotid Doppler ultrasound enables non-invasive assessment of the corrected carotid flow time (ccFT) and the carotid peak velocity variation (ΔVpeakCCA). This study aimed to evaluate the ability of ccFT and ΔVpeakCCA to predict SAIH. DesignProspective, observational, single-center study. SettingOperating room. Participants42 patients presenting for elective surgery under spinal anesthesia. InterventionsAt the holding area, the ccFT and ΔVpeakCCA were assessed with carotid Doppler ultrasound by a novice and experienced sonographer. MeasurementsIn the operating room, the occurrence of hypotension was observed for 10 min after an intrathecal injection of local anesthetic. The area under the receiver-operating curve (AUROC) was determined for ccFT and ΔVpeakCCA. The correlation between ccFT or ΔVpeakCCA and the change in blood pressure was evaluated. The interobserver agreement was assessed using the intraclass correlation coefficient (ICC) and Bland-Altman analysis. Main resultsOf all patients, 43% experienced SAIH. The ccFT was 359 ± 30 ms in normotensive and 358 ± 18 ms in hypotensive patients (p = 0.91), while the ΔVpeakCCA was 7 [6–8] % in normotensive and 7 [6–11] % in hypotensive patients (p = 0.34). The AUROC was 0.52 [0.35–0.70] for ccFT and 0.59 [0.41–0.77] for ΔVpeakCCA. There was no correlation between the percentage change in blood pressure and the ccFT or ΔVpeakCCA. The ICC between sonographers was 0.93 [0.85–0.96], (p < 0.001) for ccFT and 0.76 [0.55–0.87], (p < 0.001) for ΔVpeakCCA. The bland-Altman analysis demonstrated acceptable accuracy and precision for ccFT. ConclusionsThe ccFT and ΔVpeakCCA do not predict the occurrence of SAIH. No correlation was found between these parameters and the percentage change in blood pressure after spinal anesthesia.