Overview

Sedatives and analgesics are usually given for analgesic, anxiolytic, or sedating purposes for patients with critical illness, while they inevitably inhibit respiratory and circulatory function. Sometimes, patients receive deep sedation to induce hypoventilation or suppress spontaneous respiratory effort. The sedation level in clinical practice is usually assessed with subjective sedation scoring systems, such as the Richmond Agitation Sedation Scale (RASS). However, studies have found that sedation depth based on RASS is not a reliable marker of respiratory drive during critical illness. In recent years, researchers have proposed to monitor the effects of sedatives and analgesics on respiratory indicators and to implement lung-protective sedation, such as P0.1, Pocc, Pmus, WOB, and PTP. However, different pharmacological characteristics, different depths of sedation, and different sedation regimens among different sedatives and analgesics make a great difference in their effects on respiration. Ciprofol is an analog of propofol, with increased stereoselective effects adding to its anesthetic properties, is increasingly used in the intensive care unit, but its effects on respiration are not well understood. Therefore, this study aims to investigate the effects of ciprofol on respiratory patterns, respiratory drive, and inspiratory effort in mechanically ventilated patients.

Eligibility

Inclusion Criteria:

• The patient received surgery under general anesthesia and admitted into the ICU
• The patient has been intubated and is receiving invasively mechanically ventilated with the mode of pressure support (PSV) or continuous positive airway pressure (CPAP)
• The patient requires sedative medication targeting RASS -2 to +1 for comfort, safety and to facilitate the delivery of life support measures

Exclusion Criteria:

• Age < 18 years
• Body mass index (BMI) <18 or >30 kg/m2
• Pregnancy or lactation
• Brain stem tumors, myasthenia gravis, or neuromuscular diseases
• Acute severe neurological disorder and any other condition interfering with RASS assessment
• Systolic blood pressure < 90 mmHg after appropriate intravenous volume replacement and continuous infusions of 2 vasopressors
• Heart rate < 50 beats per minute or second- or third-degree heart block in the absence of a pacemaker
• Contraindicate or allergic to any of the study medications
• Acute hepatitis or serious hepatic dysfunction (Child-Pugh class C)
• Chronic kidney disease with glomerular filtration rate (GFR) < 60 ml/min/1.73m2
• Alcohol abuse