Clinical Research Directory

Inclusion Criteria: * Age≥ 65 years old; * Hip fracture surgery under neuraxial anesthesia; * Signed informed consent. Exclusion Criteria: * ASA classification≥ Class V; * Presence of neuraxial anesthesia contraindications: coagulation dysfunction, thrombocytopenia, neuraxial mass, puncture site infection, etc.; * Patients with contraindications to esketamine (such as allergies, intracranial aneurysms, hyperthyroidism and glaucoma); * Patients with contraindications to dexmedetomidine (allergies); * Patients with severe cardiovascular diseases such as sick sinus syndrome, severe sinus bradycardia (heart rate \< 50 beats/min), atrioventricular block grade II or above without pacemaker, unstable angina, severe valvular heart disease, severe arrhythmia, severe macrovascular disease with New York Heart Association class III patients, etc.; * Obstructive sleep apnea syndrome (STOP-BANG score \> 3 points); * Patients with severe hepatic and renal insufficiency (such as Child-Pugh score III, creatinine clearance \< 35 mL/min, preoperative dialysis); * Those who have delirium, dementia, moderate to severe cognitive dysfunction and psychiatric disorders before the start of the trial and are unable to communicate and cooperate with the investigator.