The hypothesis of this study is that Magnesium sulfate pretreatment (50mg/kg) will reduce the incidence of cough and chest wall rigidity caused by remifentanil administration.

The purpose of this study was to investigate the effect of magnesium sulfate administered before induction of anesthesia on thoracic stiffness and cough response caused by opioid analgesics administered for general anesthesia.

Inclusion Criteria:

• Patients aged 20-75 years of age who are undergoing surgery under general anesthesia using a laryngeal mask and who have consented to participate in this study among American Society of Anesthesiologists body grade 1 or 2

Exclusion Criteria:

• When coughing may occur due to an underlying disease (upper respiratory infection, rhinitis, post nasal drip, asthma, chronic obstructive pulmonary disease, pneumonia, bronchitis, current smokers, etc.)
• If you have kidney disease that can affect magnesium metabolism (glomerular filtration rate less than 60)
• If you are taking opioid analgesics or magnesium for other reasons
• Patients with hypermagnesemia
• Patients with atrioventricular block (stages I-III) or other cardiac conduction disorders
• Pregnant or lactating women
• Patients with myasthenia gravis
• Patients taking drugs that are contraindicated or interact with magnesium (barbitalates, aminoglycoside antibiotics, isoniazid, chlorpromazine, digoxin)
• In case of hypersensitivity to magnesium
• Patients with a history of hypersensitivity to propofol and any of its components
• Patients with a history of hypersensitivity to remifentanil and other fentanyl analogues