The present study aimed to assess the influence of nitroglycerin and esmolol-induced hypotension on cerebral oxygen saturation by using near-infrared spectroscopy and postoperative cognitive function in patients undergoing nasal surgery.

Inclusion Criteria:

• written informed consent
• patients with ASA physical status of I-II
• aged 18-65 years

Exclusion Criteria:

• Age under 18 or above 65
• ASA > II
• coagulation disorders
• history of cardiovascular and cerebrovascular disease
• poor Blood Pressure control
• anemia, pregnancy, addiction to opioids
• body mass index (BMI) > 35
• intraoperative systolic BP < 65 mmHg
• surgical duration less than 30 minutes or more than 160 minutes
• need for an intraoperative sympathomimetic drug and the use of other hypotensive drugs
• preoperative Mini-Mental State Examination (MMSE) score of 23 or less.

- required controlled hypotension scheduled for nasal surgeries