Ultrasound-guided regional anesthesia for carotid endarterectomy induces early hemodynamic and stress hormone changes

Objective Locoregional anesthesia is an effective method for evaluating cerebral function during carotid endarterectomy (CEA). Landmark-guided regional anesthesia (RA) is currently used for CEA and can provoke substantial perioperative hypertension. Ultrasound-guided RA (US-RA) is a new method for performing RA in CEA; however, the effect on sympathetic activity and blood pressure is uncertain. This study assessed early sympathetic activity during CEA in US-RA compared with general anesthesia (GA). Methods Patients were prospectively randomized to receive US-RA (n = 32) or GA (n = 28) for CEA. The primary end point was the change in systolic arterial blood pressure after induction of anesthesia (just before starting surgery) comparing US-RA with GA. We also recorded heart rate and analyzed concentrations of plasma blood hormones, including cortisol, metanephrine, and normetanephrine at five different times. Creatinine kinase, troponin I, and N-terminal pro-B-type natriuretic peptide were analyzed to detect potential changes in cardiac biomarkers during the procedure. Results Systolic arterial blood pressure (mean ± standard deviation) increased significantly in US-RA patients compared with GA patients even before surgery was initiated (180 ± 26 mm Hg vs 109 ± 24 mm Hg; P < .001), then remained elevated during the entire surgery and returned to baseline values 1 hour after admission to the postoperative anesthesia care unit. Heart rate (US-RA: 78 ± 16 beats/min, GA: 52 ± 12 beats/min; P < .001) and cortisol levels (US-RA: 155 ± 97 μg/L, GA: 99 ± 43 μg/L; P = .006) were also significantly higher in the US-RA group after induction of anesthesia. Other values did not differ. Conclusions The US-RA technique for CEA induces temporary intraoperative hypertension and an increase in stress hormone levels. Nevertheless, US-RA is a feasible, effective, and safe form of locoregional for CEA that enables targeted placement of low volumes of local anesthesia under direct visualization.