Comparison of analgesic efficacy between bilateral superficial and combined (superficial and deep) cervical plexus block administered before thyroid surgery

To evaluate the analgesic efficacy of bilateral superficial cervical plexus block and combined superficial and deep cervical plexus block for incision pain, headache and posterior neck pain after thyroidectomy.Ninety patients were divided into a control group (group C, n = 30), a bilateral superficial cervical plexus group (group S, n = 30) and a bilateral combined superficial and deep cervical plexus block group (group CO, n = 30). Before general anaesthesia, we performed bilateral superficial cervical plexus block (18 ml) and combined superficial (14 ml) and deep (4 ml) cervical plexus block with 0.25% bupivacaine. Anaesthesia was maintained with propofol-remifentanil-N2O-O2.The average concentration of remifentanil was significantly reduced in group S compared with group C and group CO (1.1 +/- 0.3, 1.8 +/- 0.4, 1.8 +/- 0.7 ng ml, respectively; P < 0.05). The incision pain at rest and on swallowing were significantly reduced at 0, 2 and 4 h in group S compared with group C (P < 0.05). Headache showed a tendency to be reduced in group S and group CO, but the posterior neck pain was not different among the three groups. After surgery, the opioid and nonopioid requirement was significantly reduced in group S (P < 0.05). There were fewer side effects and greater patients' satisfaction in group S.Superficial cervical plexus block is a more effective technique than combined superficial and deep cervical plexus block to reduce the pain during and immediately after thyroidectomy.