The aim of this study is to compare the degree of change in the angle of the vocal cords before and after administration of neostigmine or sugammadex. Moreover, we intend to compare the angle of vocal folds after administration of neostigmine or sugammadex.

Inclusion Criteria:

1. Adult patients who undergoes elective surgery under general anesthesia with supraglottic airway device.

Exclusion Criteria:

1. Patients under 20 years old
2. Pregnant women
3. Patients who can not read the consent form or are not fluent in Korean (illiterate, foreigner)
4. Patients who refused the clinical trial
5. Patients with dementia or cognitive impairment
6. Patients with neuromuscular disorders impairing neuromuscular blockade
7. Renal dysfunction (estimated Glomerular Filtration Rate less than 30 ml/min/1.73m2)
8. Past history of allergic reactions to neostigmine or sugammadex
9. Patients with ASA class IV or higher
10. Robotic surgery, adenoid or tonsillectomy
11. Patients with moderate or severe asthma, pulmonary function tests with forced expiratory volume for 1second of 1 liter or less, patients with upper respiratory infection symptoms within 2 weeks before surgery, current smokers (within 1 month of smoking cessation is included.)

triple (Participant, Care Provider, investigator)