The primary purpose of this study is to investigate the optimal Ce of remifentanil for preventing emergence cough following extubation during general anesthesia in male patients who are reversed with sugammadex or neostigmine.

Remifentanil is a potent ultrashort-acting opioid, with rapid onset and offset of drug effect. It allows rapid anesthetic emergence even after a prolonged infusion, and decreases the at-risk time during extubation. In addition, cough suppression of remifentanil enables smooth extubation with reduced complications. However, the infusion of remifentanil suppresses the emergence cough effectively in clinical practice, whereas it still delays the awakening from anesthesia, resulting in prolonged emergence time. Reduced Ce of remifentanil during emergence would decrease the adverse events that are associated with remifentanil infusion.

Inclusion Criteria:

• Laparoscopic cholecystectomy under general anesthesia

Exclusion Criteria:

• BMI > 30 kg/m2, respiratory infection, uncontrolled hypertension