Controlled hypotension is a widely employed technique in otolaryngological (ear, nose, and throat) surgery, primarily aimed at improving surgical field visibility and minimizing intraoperative blood loss. By maintaining mean arterial pressure within a targeted range, this approach facilitates a clearer operative field, reduces the need for blood transfusion, and shortens operative time, thereby contributing to improved surgical outcomes.

Among the pharmacological agents used to achieve controlled hypotension, remifentanil - an ultra-short-acting synthetic opioid - has gained widespread acceptance due to its rapid onset, predictable offset, and favorable hemodynamic profile. Nicardipine, a second-generation dihydropyridine calcium channel blocker, is also utilized for its potent vasodilatory properties and titratable antihypertensive effect. When used in combination, these two agents may offer complementary mechanisms of action; however, their combined impact on advanced hemodynamic parameters remains insufficiently characterized in the otolaryngological surgical setting.

The primary aim of this study is to compare the effects of remifentanil monotherapy versus remifentanil-nicardipine combination therapy on advanced hemodynamic parameters, cardiac physiology, and tissue perfusion in patients undergoing controlled hypotension during otolaryngological surgery. Advanced hemodynamic monitoring - including parameters such as cardiac output, stroke volume, systemic vascular resistance, and oxygen delivery indices - will provide a more comprehensive physiological assessment beyond conventional blood pressure measurements.

As secondary objectives, this study will evaluate and compare both regimens with respect to surgical field quality, surgeon satisfaction, intraoperative hemodynamic stability, and perioperative adverse effects. It is anticipated that a thorough comparative analysis of these two approaches will contribute to evidence-based anesthetic decision-making and help optimize patient safety and surgical outcomes in otolaryngological procedures.

Inclusion Criteria:

• Patients aged > 18 years
• American Society of Anesthesiologists (ASA) physical status I-II
• Scheduled to undergo otolaryngological surgery under general anesthesia
• Provision of written informed consent

Exclusion Criteria:

• Aged < 18 years
• ASA physical status III or higher
• Known severe cardiovascular (coronary artery disease, heart failure, uncontrolled hypertension), respiratory, renal, or hepatic disease
• Known allergy to the study drugs (remifentanil, nicardipine)
• Chronic use of beta-blockers, calcium channel blockers, or any other medication affecting blood pressure
• Pregnancy or breastfeeding
• Morbid obesity
• Emergency surgery requirement
• Refusal to participate in the study