Supraglottic airway devices (SADs) are well established in anesthetic practice. Among these devices ,classic laryngeal airway has been typically widely used. The self-pressurised air-Q (air-Q) is newly developed supraglottic airway devices. It is a new single-use device that may optimise the airway sealing while reducing the potential for postoperative complications such as sore throat. The overall structure of the air-Q SP is identical to the original air-Q, except with regard to the inflatable cuff. The aim of this randomized trial was to compare the clinical performance of the classic LMA and the air-Q SP.

Inclusion Criteria:

• Adult patients (20-75 of age) scheduled for elective surgery of short duration (less than 2 hr) undergoing general anesthesia using supraglottic airway

Exclusion Criteria:

• Patients with a potentially difficult airway, risk of aspiration such as gastroesophageal reflux disease, or active upper respiratory tract infection