Night-time Dexmedetomidine-esketamine Infusion and Sleep Quality in ICU Patients

Inclusion Criteria:

• Aged 50 years or older;

• Admitted to the intensive care unit (ICU) after surgery;

• Receiving mechanical ventilation or high-flow nasal cannula oxygen therapy duringnight-time (after 6 pm), with an expected duration of ≥12 hours.

Exclusion Criteria:

• Duration of invasive/non-invasive ventilation ≥12 hours before enrollment;

• Planning to receive muscle relaxant treatment;

• History of schizophrenia, epilepsy, Parkinson's disease, or myasthenia gravis;

• Unable to communicate due to coma, delirium, severe dementia, or language barrierbefore receiving mechanical ventilation or high-flow nasal cannula oxygen therapy;

• Acute stroke or hypoxic encephalopathy, or after craniocerebral injury orneurosurgery;

• Comorbid with hyperthyroidism or pheochromocytoma;

• Taking sedative/hypnotic drugs or analgesics regularly (for more than 1 week) in thelast month;

• LVEF<30%; sick sinus syndrome, severe sinus bradycardia (heart rate<50 beats/min),atrioventricular block of more than II degree and without pacemaker; or systolicblood pressure <90 mmHg despite vasopressor infusion;

• Severe liver dysfunction (Child-Pugh C grade), severe renal dysfunction (dialysis),or estimated survival ≤24 hours;

• Diagnosed obstructive sleep apnea, or body mass index >30 kg/m2;

• Allergies to dexmedetomidine and/or esketamine, or other conditions that areconsidered unsuitable for study participation;

• Enrolled in other clinical studies.