Efficacy and Safety of Remifentanil for Mechanically Ventilated Patients in ICU

Inclusion Criteria:

• Invasive mechanical ventilation with endotracheal intubation
• Expected to continue mechanical ventilation for more than 12 hours
• Informed consent/assent was obtained from all patients or their representatives

Exclusion Criteria:

• Patients with a history of allergy to opioids, benzodiazepines, propofol, oralcohol/drug abuse were excluded from the study
• Patients who are known or suspected to be allergic to the study drug
• Patients whose expected survival time is less than 48h
• Patients receiving deep sedation (RASS≥-4)
• Patients using neuromuscular blocking agent
• Patients who cannot be assessed by RASS
• Patients with myasthenia gravis
• patients with bronchial asthma
• patients with abdominal compartment syndrome
• Patients who need surgery or tracheotomy during the study drug treatment period
• Women during pregnancy and lactation
• Patients who have used short-acting non-steroidal anti-inflammatory drugs within 6hours
• Patients who have used long-acting non-steroidal anti-inflammatory drugs within 12hours
• Patients with a history of chronic pain for more than 3 months or who are receivingregular analgesia for more than 3 months
• Patients who have used monoamine oxidase inhibitors within two weeks
• Patients who participate in any clinical trials as subjects within 1 month
• Patients with a history of drug abuse, drug abuse, alcohol abuse* and long-term use ofpsychotropic drugs within 2 years Alcoholism: Drinking more than 14 times/week (1time=150ml wine or 360ml beer or 45ml spirits)