Use of the intubating laryngeal mask airway - Are muscle relaxants necessary?

Background: The intubating laryngeal mask ah-way (ILMA) is designed to faci litate blind tracheal intubation, The effect of a muscle relaxant on the ab ility to perform tracheal intubation through the ILMA device has not been p reviously evaluated. This randomized, double-blind, placebo-controlled stud y was designed to evaluate rocuronium, 0.2 or 0.4 mg/kg administered intrav enously, on the success rate and incidence of complications associated with ILMA-assisted tracheal intubation, Methods: A total of 75 healthy patients were induced with propofol 2 mg/kg and fentanyl 1 mu g/kg intravenously. After insertion of the ILMA device, p atients were administered either saline, rocuronium 0.2 mg/kg, or rocuroniu m 0.4 mg/kg in a total volume of 5 mi. At 90 s after administration of the study drug, tracheal intubation was attempted using a disposable polyvinyl tube. If unsuccessful, a reusable silicone tube was tried. In addition to r ecording the time and number of attempts required to secure the airway, the incidence of complications during placement of the tracheal tube and remov al of the ILMA were noted. Results: Tracheal intubation was successful in. 76-96% of the patients. The overall success rates and times required to secure the airway were similar in all three treatment groups. The high-dose rocuronium group experienced less patient movement (8 vs. 28 and 48%) and coughing (12 vs. 20 and 52%) t han the low-dose rocuronium and saline groups, respectively. Use of rocuron ium was also associated with a dose-related decrease in the requirement for supplemental bolus doses of propofol during intubation and removal of the ILMA device. Conclusions: Use of rocuronium did not significantly improve the success ra te in performing tracheal intubation through the ILMA. However, it produced dose-related decreases in coughing and movement after tracheal intubation and reduced difficulties associated with removal of the ILMA device.