The effect of adding dexamethasone to the ultrasound-guided intermediate cervical plexus block in thyroidectomy: A double-blind randomized controlled study

Abstract

Background: A bilateral superficial cervical plexus block provides good analgesia for neck surgery, including thyroidectomy. However, the duration of a single shot nerve block is usually short. Therefore, adjuvants are used in peripheral nerve blocks, especially with ambulatory surgery, where the analgesia duration is very important. Methods: Sixty patients scheduled for thyroidectomy were randomly assigned to one of two groups. Group C received general anesthesia and a bilateral intermediate cervical plexus block with isobaric 10 ml bupivacaine 2% + 2 ml NS deposited on each side. Group D received general anesthesia and bilateral intermediate cervical plexus block with 10 ml isobaric bupivacaine 2% + 4 mg (2 ml) dexamethasone deposited on each side. Primary outcome was postoperative analgesia evaluated by the VAS score. Secondary outcomes were perioperative IL6, blood glucose level, and postoperative nausea and vomiting. Results: Postoperative pain VAS scores were significantly lower in the dexamethasone group than control group; mean VAS score at 6 h postoperatively was 0.4 in Group D vs. 1.8 in Group C; P <0.001, at 8 h it was 0.4 vs. 2.6; P <0.001 in Group D and C, respectively, and in 24 h it was 3.5 in Group D vs. 5 in Group C; P 0.003. Analgesia duration was significantly longer in the dexamethasone group: 12 h versus 6 h in the control group; P<0.001. Postoperative IL-6 at 8 and 24 h postoperatively were significantly lower in the dexamethasone group than the control group (36.8 vs 21; P <0.001) and (18.9 vs 13; P<0.001), respectively. Non-significant changes could be detected between both groups in intraoperative bleeding and postoperative glycemic control. Conclusion: The addition of 8 mg dexamethasone to ultrasound-guided intermediate cervical plexus block can enhance analgesia duration and reduce postoperative opioid consumption and postoperative IL-6 levels with no significant effect on postoperative glycemic control in non-diabetic patients undergoing thyroidectomy under general anesthesia.