Randomized controlled trial comparing bilateral superficial cervical plexus block and local wound infiltration for pain control in thyroid surgery

Abstract

Summary: Backgroud/objective: Multiple approaches have been devised for pain control in patients undergoing thyroid surgery, with local wound infiltration (LWI) of analgesia and bilateral superficial cervical plexus block (BSCPB) among the popular choices cited. However, the results comparing these methods had either been contradictory or equivocal. This study was carried out to assess the efficacy of BSCPB in comparison to LWI in reducing post-operative pain, as well as any additional opioid requirement in the first 24 h after thyroid surgery. Methods: A prospective, double-blinded randomized controlled trial comparing the post-operative pain score between BSCPB and LWI was conducted among patients undergoing thyroid surgery. Ropivacaine 0.50% was used in the study. Pain score was measured at 4, 12, 16 and 24 h after surgery using the visual analog scale (VAS). Subcutaneous injection of Tramadol was given whenever the pain score was ≥4 or requested by patients. Results: A total of 70 patients were recruited, with 35 patients on each arm. There was no statistical difference in the post-operative pain score between the two groups at 4 h (p = 0.208), 12 h (p = 0.860), 16 h (p = 0.376) and 24 h (p = 0.375) after surgery. Time to the first rescue dose of Tramadol between the two arms was also insignificant (p = 0.949). One patient in the BSCPB arm developed transient left upper limb weakness, which resolved 12 h after surgery. Conclusion: LWI remains the simplest, safest and most economical method of pain management. While BSCPB is comparable, it does however, come with potential regional block related complications. Keywords: Thyroid surgery, Superficial cervical plexus block, Local wound infiltration, Pain control, 24 h