Comparison of the ED50 propofol requirements during the insertion of laryngeal mask airway Ambu AuraFlex with Ambu AuraOnce in children undergoing strabismus surgery.

ABSTRACT

WHAT IS KNOWN AND OBJECTIVE: Optimal airway management is crucial in strabismus surgery due to the inaccessibility of the airway throughout the procedure. Laryngeal mask airway offers advantages over tracheal intubation in ophthalmic surgery as it does not increase the intraocular pressure. The purpose of this study was to determine the median effective dose of propofol required, when combined with 0.2 µg/kg of sufentanil, for smooth insertion of Ambu AuraFlex in the first attempt in children undergoing strabismus surgery, and to compare it with that for Ambu AuraOnce. METHODS: Forty-three paediatric patients undergoing strabismus surgery under general anaesthesia were recruited. For induction, the initial dosage of propofol was 2 mg/kg in the AuraOnce group or 3 mg/kg in the AuraFlex group. In accordance with Dixon's up-and-down method, the dose of propofol for consecutive patients in each group was adjusted in increments or decrements of 0.25 mg/kg based on the previous patient's "three-point, six-category scale" response to the first attempt of insertion of the randomized device. Insertion of the device was attempted when the bispectral index was ≤60 for 5 s after propofol administration without the use of neuromuscular blocking agents. RESULTS AND DISCUSSION: The median effective dose (95% confidence interval) of propofol was significantly lower in the Ambu AuraOnce group than in the Ambu AuraFlex group (1.92 [1.50-2.32] mg/kg vs. 2.98 [2.49-3.94] mg/kg; p = 0.002). The incidence of dislodgement of the device was significantly higher with the use of the Ambu AuraOnce than with the use of AuraFlex (p = 0.023), whereas insignificant differences were observed between the two groups in the incidence of other perioperative adverse events. WHAT IS NEW AND CONCLUSION: Ambu AuraFlex requires a significantly higher dose of propofol for insertion and provides more effective and stable airway management in strabismus surgery than AuraOnce.