Bilateral superficial cervical plexus block improves pain control after thyroidectomy under general anesthesia: a randomized, double-blind, clinical trial

Background: Thyroidectomy is a surgical procedure that causes mild to moderate pain after surgery, which needs adequate management. Various pain control regimens have been used for this purpose including narcoticanalgesics, non-steroidal anti-inflammatory drugs (NSAIDs) and regional techniques. We studied the efficacy of bilateral superficial cervical plexus blocks (SCPB) under ultrasound guidance on post-operative pain after thyroidectomy under general anesthesia.Methodology: This randomized double-blind clinical controlled trial was conducted on sixty patients, who were randomly allocated to either Group I, to receive bilateral ultrasound guided SCPB with 8 ml of ropivacaine 0.5%, or to Group II (control group) to receive injection of normal saline. Rescue analgesics were used if VAS was >= 4. For the primary evaluation of first 24 h after surgery, the criteria included VAS score at rest, at neck movements, at swallowing and vocalization; and analgesic-related variables such as time to first rescue analgesia, the number of patients requiring analgesics rescue, the incidence of PONV and the rate of complications. To obtain the long-term outcome, the enrolled patients were monitored to observe the rate of chronic pain after three months of thyroidectomy based on the Douleur Neuropathique 4 questions (DN4) score.Results: Within 24 h after surgery, the postoperative VAS score in the Group I was lower than in the control group. Moreover, the Group I patients could tolerate the pain longer than those of Group II, and required the first dose of analgesic later. They also required a lower dose of ketorolac and had reduced the incidence of postoperative nausea or vomiting (PONV). In addition, after 3 months, the frequency of chronic pain in the Group I was lower compared to the control group.Conclusions: The results of our study confirm that bilateral superficial cervical plexus blocks under ultrasound guidance method as a part of multi-modal analgesia have a great potential in managing pain after thyroid surgery. The side effects and complications were observed to be statistically non-significant.