Age

18–75

Sex

ALL

Healthy volunteers

Not accepted

Severe hepatic or renal insufficiency
Allergy to dexmedetomidine or its excipients
Severe bradycardia (heart rate \<50 bpm), sick sinus syndrome, or second-/third-degree AV block without pacemaker
Use of α2-agonists, benzodiazepines, or other sedatives/analgesics within 24 hours preoperatively
History of alcohol, drug, or psychoactive substance dependence
Diagnosed or suspected obstructive sleep apnea syndrome
Nasal anatomical abnormalities, acute rhinitis, epistaxis, or other nasal conditions affecting drug administration
Pregnancy or lactation
Communication barriers, psychiatric disorders, or cognitive impairment precluding scale completion
Visual/hearing impairment or inability to read

The Impact of Dexmedetomidine Nasal Spray on Perioperative Anxiety in Neurosurgical Patients