Analgesic efficacy of bilateral superficial cervical plexus block administered before thyroid surgery under general anaesthesia

Background: The use of regional anaesthesia in thyroid surgery remains controversial.This double-blind, randomized controlled study was conductedto evaluate the analgesic efficacy of bilateral superficialcervical plexus block (BSCPB) performed under general anaesthesiain patients undergoing total thyroidectomy. Methods: Eighty-seven consecutive consenting patients were randomizedto receive a BSCPB with saline (Group P, n = 29), ropivacaine0.487% (Group R, n = 29), or ropivacaine 0.487% plus clonidine5 µg ml^–1 (Group RC, n = 29). Sufentanil was givenduring the intraoperative period for a 20% increase in arterialmean pressure or heart rate in a patient with a bispectral indexbetween 40 and 60. All patients received 4 g of acetaminophenduring the first 24 h after operation. The pain score was checkedevery 4 h and nefopam was given for pain score >4 on a numericpain scale. Results: During surgery, the median sufentanil requirements were significantlyreduced in Group RC compared with Groups R and P (0.32 vs 0.47and 0.62 µg kg^–1; P < 0.0001). After surgery,the number of patients requiring nefopam within 24 h of surgerywas significantly lower in Groups R and RC than in Group P (16and 19 vs 25; P = 0.03). At post-anaesthetic care unit admission,median (range) pain scores were significantly lower in GroupsR [3 (0–10)] and RC [3 (0–8)] than in Group P [5(0–8), P = 0.03]. No major complications of BSCPB occurredduring study. Conclusions: BSCPB with ropivacaine and clonidine improved intraoperativeanalgesia. BSCPB with ropivacaine or ropivaciane and clonidinewas effective in reducing analgesic requirements after thyroidsurgery.