Awake Sedation With Propofol Attenuates Intraoperative Stress of Carotid Endarterectomy in Regional Anesthesia

Abstract

Carotid endarterectomy in regional anesthesia is often associated with increased perioperative stress. We assumed that carotid endarterectomy performed under awake sedation with propofol is more beneficial to prevent such stress than alprazolam premedication only. A total of 47 consecutive patients with significant carotid artery stenosis were enrolled into this investigation and followed up for 5years to explore vascular complications. All operations were performed under regional anesthesia. As premedication, all patients took 0.5mg of alprazolam 30minutes before the procedure. After randomization, 22 patients had awake sedation with target controlled propofol infusion, and the other 25 had only premedication. Cortisol plasma levels were serially analyzed: before surgery (T1), before (T2) and after release of carotid clamp (T3), and at 2 (T4) and 24 postoperative hours (T5). Alprazolam levels were also measured before and after the surgery. The plasma concentration of cortisol was significantly lower in the propofol sedation group at T2 (P<0.001), T3 (P=0.001), and T4 (P<0.001) than in the alprazolam-only group. Alprazolam levels did not correlate with cortisol levels at any time point. A significant positive correlation was found between the clamp time and plasma cortisol level at T3 (P=0.018), similarly between the degree of contralateral carotid stenosis and plasma cortisol level at T3 (P=0.03). Plasma cortisol concentration 2hours after the operation (T4) proved to be an independent predictor of carotid restenosis during the 5-year follow-up (odds ratio: 1.67, 95% confidence interval: 1.02-2.73, P=0.04). An additional intraoperative propofol sedation provides better stress relief than alprazolam-only premedication during awake carotid endarterectomy.