Clinical Study on the Efficacy and Safety of Hydromorphone for ICU Analgesia

Inclusion Criteria: * Age ≥18 years and ≤75 years; * For patients requiring sedation and analgesia in ICU, invasive mechanical ventilation time is expected to be ≥24 hours; * Obtain informed consent from patients or family members. Exclusion Criteria: * Under 18 years of age, or over 75 years of age; * pregnancy or breastfeeding; * Known or suspected allergy to opioids (e.g., fentanyl, remifentanil, hydromorphone), butorphanol, midazolam. * General anesthesia surgery within 48 hours; * Acute bronchial asthma. * Acute intestinal obstruction. * General anesthesia surgery within 48 hours; * ECG QT interval: male \>450 mm seconds, female \>470 ms. * Failure to obtain informed consent or authorization; * Participate in other exploratory clinical trials within 6 months prior to screening; * Severe hemodynamic instability (requires epinephrine greater than 0.5ug/kg/min to maintain MAP\>65mmHg, or malignant arrhythmias frequently occur) * Use of monoamine oxidase inhibitors. * Chronic pain requires long-term analgesics (\>3 months). * Severe, pre-existing substantial liver disease with clinically significant portal hypertension, Child-Pugh grade C cirrhosis, or acute liver failure; * Patients with acute and chronic renal insufficiency requiring dialysis treatment; * Severe craniocerebral injury, brain tumor, increased intracranial pressure, cerebrovascular accident, coma, epileptic status, etc. * Patients with a history of alcohol or drug abuse; * Any condition that prevents the correct assessment of cognitive function, such as speech and sensory disorders or mental disorders (language difficulties or organic mental dysfunction); * any other conditions which the investigator considers inappropriate for registration.