Clinical Research Directory

Inclusion Criteria: * 18 years ≤ age ≤ 85 years; * Patients scheduled to undergo elective coronary angiography or percutaneous coronary intervention (PCI); * Classified as American Society of Anesthesiologists (ASA) physical status I-III (ranging from patients with mild systemic disease to those with more severe systemic disease that limits normal physical activity but who remain able to perform light daily tasks); * Informed consent obtained. Exclusion Criteria: * Allergy or contraindication to dexmedetomidine, such as severe bradycardia (resting heart rate \<50 beats/min), sick sinus syndrome, second-degree or higher atrioventricular block without a pacemaker; * Severe cardiac dysfunction (left ventricular ejection fraction \<35% or New York Heart Association functional class III-IV), cardiogenic shock, or hemodynamically unstable patients; * Uncontrolled hypertension (systolic blood pressure \>180 mmHg or diastolic blood pressure \>110 mmHg) or hypotension (systolic blood pressure \<90 mmHg); * Sleep apnea-hypopnea syndrome or Body Mass Index \>30 kg/m²; * Use of alpha-2 adrenergic receptor agonists (e.g., clonidine) or antagonists, or tricyclic antidepressants, which may affect the action of the study drug, within 1 month before the procedure; * Language, visual, or hearing impairment that may affect cognitive assessment; * Hepatic or renal insufficiency (Alanine Aminotransferase/Aspartate Aminotransferase/Creatinine \>3 times the upper limit of normal); * Anatomical abnormalities of the nasal cavity affecting intranasal drug administration; * Pregnant or breastfeeding women.