Deep neuromuscular block improves the surgical conditions for laryngeal microsurgery

Br J Anaesth. 2015 Dec;115(6):867-72. doi: 10.1093/bja/aev368.


Background: Adequate neuromuscular block is required throughout laryngeal microsurgery. We hypothesized that the surgical conditions would improve under a deeper level of rocuronium-induced neuromuscular block.

Methods: Seventy-two patients undergoing laryngeal microsurgery were randomly allocated to either the 'post-tetanic counts 1-2' (PTC1-2) group or the 'train-of-four counts 1-2' (TOFcount1-2) group according to the level of neuromuscular block used. Two different doses of rocuronium (1.2 or 0.5 mg kg(-1)) were used after anaesthetic induction, and two respective targets of neuromuscular block (post-tetanic counts ≤2 or train-of-four count of 1 or 2) were used. Surgical conditions were assessed by the surgeon using a five-point rating scale (extremely poor/poor/acceptable/good/optimal), and clinically acceptable surgical conditions were defined as those which were rated acceptable, good, or optimal. The occurrence of vocal cord movement and postoperative adverse events was assessed.

Results: The surgical conditions were significantly different between the PTC1-2 and TOFcount1-2 groups (extremely poor/poor/acceptable/good/optimal: 0/2/1/7/26 and 3/10/2/14/7, respectively, P<0.001). The incidence of clinically acceptable surgical conditions was significantly higher in the PTC1-2 group than in the TOFcount1-2 group (94 vs 64%, P=0.003). The percentage of patients who exhibited vocal cord movement was significantly lower in the PTC1-2 group than in the TOFcount1-2 group (3 vs 39%, P<0.001). The incidence of postoperative adverse events was not significantly different except for the less frequent occurrence of mouth dryness in the PTC1-2 group (P=0.035).

Conclusions: Deep neuromuscular block (post-tetanic count of 1-2) surgical conditions in patients undergoing laryngeal microsurgery improves.

Clinical trial registration: NCT01980069.

Keywords: larynx; neuromuscular blockade; neuromuscular monitoring.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Aged
  • Androstanols / administration & dosage*
  • Anesthesia, General / methods
  • Dose-Response Relationship, Drug
  • Female
  • Humans
  • Larynx / surgery*
  • Male
  • Microsurgery / adverse effects
  • Microsurgery / methods*
  • Middle Aged
  • Monitoring, Intraoperative / methods
  • Neuromuscular Blockade / methods*
  • Neuromuscular Junction / drug effects
  • Neuromuscular Junction / physiopathology
  • Neuromuscular Nondepolarizing Agents / administration & dosage*
  • Prospective Studies
  • Rocuronium
  • Young Adult


  • Androstanols
  • Neuromuscular Nondepolarizing Agents
  • Rocuronium

Associated data