Comparison of four facial muscles, orbicularis oculi, corrugator supercilii, masseter or mylohyoid, as best predictor of good conditions for intubation: a randomised blinded trial.

CONTEXT: Monitoring of facial muscles after neuromuscular blockade can give an early indication of respiratory muscle readiness for tracheal intubation. OBJECTIVE: To assess which facial muscle, the orbicularis oculi, corrugator supercilii, masseter or the mylohyoid, is the best predictor of readiness for intubation after rocuronium. DESIGN: Prospective, randomised, blinded trial. SETTING: Single centre: Seoul, Korea, from August 2012 to November 2012. PATIENTS: Two hundred and eighty-eight patients aged 22 to 64 years were randomised to one of eight study groups: orbicularis oculi, corrugator supercilii, masseter and mylohyoid for rocuronium 0.6 or 1.2 mg kg. INTERVENTION: The maximum twitch depression at the eyelid (orbicularis oculi), the superciliary arch (corrugator supercilii), the cheek (masseter) and the submental triangle (mylohyoid) was assessed after rocuronium 0.6 and 1.2 mg kg. Endotracheal intubation was performed after maximal neuromuscular blockade, and intubating conditions were appraised. MAIN OUTCOME MEASURES: The onset time of rocuronium and the quality of the intubation conditions were assessed. RESULTS: The onset times in the orbicularis oculi, corrugator supercilii and masseter were significantly faster than that in the mylohyoid (P < 0.001). 'Clinically acceptable' intubation conditions were significantly enhanced in the mylohyoid (94%) compared with those in the orbicularis oculi (80%) and masseter (78%) after rocuronium 0.6 mg kg (P < 0.05), and no difference with corrugator supercilii (92%). Despite differences in onset time of orbicularis oculi and masseter compared to mylohyoid (P < 0.05), intubating conditions were similar among the four muscles after rocuronium 1.2 mg kg. CONCLUSION: Following rocuronium 0.6 mg kg at similar depths of anaesthesia, the monitoring of the corrugator supercilii provided the best balance of a shorter onset time while maintaining 'clinically acceptable' intubation conditions. TRIAL REGISTRATION: IRB File No.: HYUH 2012-07-009.

The efficacy of several neuromuscular monitoring modes at the P6 acupuncture point in preventing postoperative nausea and vomiting.

BACKGROUND: In this study, we tested the efficacy of several neuromuscular monitoring modes at the P6 acupuncture point for preventing postoperative nausea and vomiting (PONV). METHODS: In this prospective, double-blind, randomized, placebo-controlled trial, 264 women undergoing laparoscopic hysterectomy were evaluated for PONV. Neuromuscular blockade was monitored by acceleromyography with 1-Hz single twitch (ST) over the ulnar nerve (n = 54, control), and ST (n = 52), train-of-four (n = 53), double-burst stimulation (n = 53), or tetanus (n = 52) over the median nerve stimulating at the P6 acupuncture point. RESULTS: The incidence of PONV (P = 0.022), the number of requests for patient-controlled analgesia (P = 0.009), and total patient-controlled analgesia volume (P = 0.042) 6 hours after tetanic stimulation were significantly reduced in the treatment group compared with the control group. Overall, patients in the tetanus group were more satisfied with the management of PONV compared with patients in the control group. CONCLUSION: Tetanic stimulation applied to the P6 acupuncture point can reduce PONV after laparoscopic hysterectomy compared with ST stimulation of the ulnar nerve, resulting in a greater degree of patient satisfaction. None of the stimulations, ST, train-of-four, or double-burst, applied to the P6 acupuncture point significantly affected PONV.

The dose effect of ephedrine on the onset time of vecuronium.

UNLABELLED: A small dose of ephedrine decreases the onset time of rocuronium and cisatracurium; however, ephedrine might be associated with adverse hemodynamic effects. The appropriate dose of ephedrine has not been determined. We, therefore, studied 120 patients anesthetized with fentanyl 2 microg/kg and propofol 2-2.5 mg/kg who were randomly divided to receive either ephedrine (30, 70, or 110 microg/kg) or saline. During propofol anesthesia, the neuromuscular block was monitored by mechanomyography by using submaximal current of train-of-four stimulation every 10 s. To determine cardiac output, a transcutaneous Doppler probe was placed externally at the suprasternal notch. Tracheal intubation was performed by a blinded investigator at 2 min after vecuronium. Neuromuscular block, intubating conditions, and hemodynamic effects were measured during the induction of anesthesia. Both ephedrine 70 and 110 microg/kg improved intubating conditions at 2 min after vecuronium; however, 110 microg/kg was associated with adverse hemodynamic effects. We conclude that ephedrine 70 microg/kg given before the induction of anesthesia improved intubating conditions at 2 min after vecuronium, probably by increased cardiac output without significant adverse hemodynamic effects. IMPLICATIONS: Ephedrine 70 microg/kg given before the induction of anesthesia improved tracheal intubating conditions at 2 min after vecuronium by increased cardiac output without significant adverse hemodynamic effects.