The Effects of Deep Neuromuscular Blockade During Robot-assisted Transaxillary Thyroidectomy on Postoperative Pain and Sensory Change
Condition: Thyroid Neoplasms
MeSH terms: Thyroid Neoplasms; Pain, Postoperative
Study type: Interventional

Summary: 
      As robotic surgery has been applied to various surgeries, the minimally invasive surgery is
      rapidly evolving. In particular, robot-assisted thyroidectomy is one of the leading
      techniques in minimally invasive surgery fields. Robot-assisted transaxillary thyroidectomy
      dramatically improves the cosmetic satisfaction, showing no difference in cancer control and
      safety comparing with conventional open thyroidectomy. However, some studies have shown that
      many patients complained of chest pain after robot-assisted thyroidectomy, and about 20% of
      patients suffered chronic pain even after three months of surgery. This might be due to the
      flap formation during robot-assisted thyroidectomy.

      Robot-assisted transaxillary thyroidectomy does not provide visibility by injecting CO2. But
      it provides visibility using Chung's retractor system to make a flap between the pectoralis
      major muscle and subcutaneous fat layer. The flap is formed from the incision of axilla to
      the anterior neck to approach the thyroid gland. In this progress, it requires considerable
      force to maintain the Chung's retractor system, and additional pressure may be applied to the
      subcutaneous fat and skin constituting the skin flap. The pressure applied to the skin flap
      may be associated with postoperative pain and sensory abnormality, but it has not been
      studied yet.

      Deep neuromuscular blockade The neuromuscular block for muscle relaxation during surgery is
      essential for general anesthesia. In general, a neuromuscular block agent is used to induce
      intubation during induction of anesthesia. Continuous or single injection of neuromuscular
      block agent is then carried out as needed during the operation.

      The effect of deep neuromuscular blockade on laparoscopic surgery using carbon dioxide has
      already been studied. Deep neuromuscular blockade on laparoscopic surgery reduced
      postoperative pain and improved the surgical condition compared to conventional moderate
      neuromuscular blockade. However, the effect of neuromuscular blockade on robot-assisted
      thyroid surgery has not been studied yet.

      There was concern about delayed recovery of muscle relaxation and respiratory failure due to
      deep neuromuscular blockade. However, the development of sugammadex (Bridion, Merck Sharp and
      Dohme - MSD, Oss, Netherlands) eliminated these concerns. Sugammadex dramatically reduced the
      recovery time from deep neuromuscular blockade.
    


Intervention name(s): Deep Group; Control Group
Intervention type(s): Drug; Drug
Intervention description(s): Continuous Rocuronium (Rocnium®, Hanlim Pharm. Co., Ltd., South Korea) infusion during surgery
Titrate Rocuronium (Rocnium®) infusion rate to maintain TOF = 0 & PTC= 1~2 (TOF = train-of-four. PTC = post-tetanic count)
TOF and PTC are assessed by acceleromyography (TOF-Watch® SX, Organon Ltd., Drynam Road, Swords, Co. Dublin, Ireland).
At the end of surgery, IV Sugammadex (Bridion®, Merck Sharp and Dohme [MSD], Oss, the Netherlands) injection to reverse muscle relaxation.
Sugammadex dose = 2mg/kg at TOF ≥2 or 4mg/kg at TOF < 2; Continuous Rocuronium (Rocnium®, Hanlim Pharm. Co., Ltd., South Korea) infusion during surgery
Titrate Rocuronium (Rocnium®) infusion rate to maintain TOF = 1~2
TOF and PTC are assessed by acceleromyograph (TOF-Watch® SX, Organon Ltd., Drynam Road, Swords, Co. Dublin, Ireland).
At the end of surgery, IV Sugammadex (Bridion®, Merck Sharp and Dohme [MSD], Oss, the Netherlands) injection to reverse muscle relaxation.
Sugammadex dose = 2mg/kg at TOF ≥2 or 4mg/kg at TOF < 2
Other intervention name(s): Deep Neuromuscular Block; Moderate Neuromuscular Block
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Deep group
Continuous rocuronium infusion during surgery
Maintain TOF = 0 & PTC= 1~2 (Deep neuromuscular block)
Control group
Continuous rocuronium infusion during surgery
Maintain TOF 1~2 (Moderate neuromuscular block)
Masking: Double (Participant, Care Provider)
Primary purpose: Prevention