The Analgesic Efficacy of Bilateral Combined Superficial and Deep Cervical Plexus Block Administered Before Thyroid Surgery Under General Anesthesia

In this study we evaluated the analgesic efficacy of combined deep and superficial cervical plexus block in patients undergoing thyroidectomy under general anesthesia. For this purpose, 39 patients undergoing elective thyroid surgery were randomized to receive a bilateral combined deep and superficial cervical block (14 mL per side) with saline (Group 1;n = 13), ropivacaine 0.5% (Group 2;n = 13), or ropivacaine 0.5% plus clonidine 7.5 μg/mL (Group 3;n = 13). Deep cervical plexus block was performed with a single injection (8 mL) at the C3 level. Superficial cervical plexus block consisted of a subcutaneous injection (6 mL) behind the lateral border of the sternocleidomastoid muscle. During surgery, the number of additional alfentanil boluses was significantly reduced in Groups 2 and 3 compared with Group 1 (1.3 ± 1.0 and 1.1 ± 1.0 vs 2.6 ± 1.0;P < 0.05). After surgery, the opioid and non-opioid analgesic requirements were also significantly reduced in Groups 2 and 3 (P < 0.05) during the first 24 h. Except for one patient in Group 3, who experienced transient anesthesia of the brachial plexus, no side effect was noted in any group. We conclude that combined deep and superficial cervical plexus block is an effective technique to alleviate pain during and immediately after thyroidectomy.