Different effects of intravenous and local anesthesia in patients undergoing ultrasound-guided radiofrequency ablation of thyroid nodules: a prospective cohort study

Abstract

Purpose: To compare the efficacy and safety of intravenous anesthesia (IV) with local anesthesia (LA) in patients undergoing ultrasound (US)-guided radiofrequency ablation (RFA) of thyroid nodules. Methods: 50 patients with American Society of Anesthesiologists classification grades I–II undergoing US-guided thyroid RFA were enrolled and randomly (1:1) divided into IV (conscious sedation with Ramsay Sedation Scale [RSS] scores of 2–3 with an anesthesiologist) and LA (subcutaneous anesthesia with lidocaine without an anesthesiologist) groups. Pre-, intra- and post-procedural blood pressure (BP) (SBP0/DBP0, SBP1/DBP1, and SBP2/DBP2), intra- and post-procedural pain (NRS1 and NRS2), ablated area volume, treatment time and adverse events were analyzed and compared. Results: Age, sex, weight, number, nature, volume of nodules, and SBP0/DBP0 showed no difference between both groups. 11 and 0 patients’ SBP1/DBP1 were elevated in the LA and IV groups. NRS1 differed between both groups. 6 patients in the LA group had moderate or severe pain, but none in the IV group. No between-group difference in SBP2/DBP2, NRS2, ablation completion rate and ablated volume was noted. The median procedure duration differed from 1109 (176) s in IV group and 723 (227) s in LA groups. There was no increased incidence of adverse events in IV group. Conclusions: IV with RSS scores of 2–3 maintained intra-procedural BP and relieved intra-procedural pain better, without affecting the ablation efficacy and increasing complications. Despite increased treatment time, IV is a potential option for patients undergoing US-guided RFA of thyroid nodules.