Ciprofol Versus Propofol With Low-Dose Sufentanil for Painless Bronchoscopy

This was a prospective, single-center, randomized, parallel-group, superiority clinical study conducted at the outpatient department of Wenzhou Central Hospital. The study was designed to compare the efficacy and safety of ciprofol combined with low-dose sufentanil with those of propofol combined with low-dose sufentanil in patients undergoing bronchoscopy under intravenous sedation.

A total of 100 participants aged 35 to 65 years, weighing 45 to 80 kg, and classified as American Society of Anesthesiologists physical status I or II were enrolled. Participants were randomly assigned in a 1:1 ratio to the ciprofol group or the propofol group, with 50 participants in each group. Randomization was performed using a pre-generated random-number table. Allocation concealment was implemented using opaque, sequentially numbered, sealed envelopes that were opened immediately before administration of anesthesia.

Participants were unaware of their treatment assignment. Personnel responsible for recording vital signs, recovery indicators, and adverse events were separated from the anesthesiologists administering the study medications and from the physicians performing bronchoscopy, and remained unaware of treatment assignment during data collection.

All participants fasted for 8 hours and avoided oral fluids for 4 hours before bronchoscopy. Peripheral intravenous access was established, Ringer's acetate solution was administered at 6 to 8 mL/kg/hour, and electrocardiography, noninvasive blood pressure, heart rate, and oxygen saturation were continuously monitored. Oxygen was administered through a nasal cannula at 5 L/min.

Participants assigned to the ciprofol group received sufentanil 0.1 micrograms/kg by slow intravenous injection, followed by ciprofol 0.4 mg/kg by slow intravenous injection. Participants assigned to the propofol group received sufentanil 0.1 micrograms/kg by slow intravenous injection, followed by propofol 1.5 mg/kg by slow intravenous injection. Each study medication was administered over more than 30 seconds. Bronchoscopy was initiated after disappearance of the eyelash reflex and achievement of a Modified Observer's Assessment of Alertness/Sedation score of 1 or lower.

The primary outcome measures were the total dose of sedative medication and the overall incidence of peri-procedural adverse events. Secondary outcome measures included sedation onset time, bronchoscopy procedure time, recovery time, Steward recovery score, mean arterial pressure, heart rate, oxygen saturation, individual adverse events, and overall anesthesia effectiveness.

This exploratory study did not include a formal prospective sample-size or statistical-power calculation. The planned sample size of 100 participants was based on the feasibility of enrollment during the study period and the sample sizes used in previous exploratory studies of intravenous sedatives for outpatient endoscopic procedures.

The study was reviewed and approved by the Ethics Committee of Wenzhou Central Hospital, approval number 2022-68. Written informed consent was obtained from all participants before enrollment.

Inclusion criteria

• Age 35 to 65 years.
• Body weight 45 to 80 kg.
• American Society of Anesthesiologists physical status I or II.
• Scheduled to undergo painless bronchoscopy.
• No contraindications to intravenous anesthesia.
• Willing and able to cooperate with study procedures.
• Provided written informed consent.

Exclusion criteria

• Body mass index greater than 40 kg/m².
• Uncontrolled hypertension, defined as systolic blood pressure greater than 180 mmHg.
• Severe cardiac arrhythmia.
• Unstable angina.
• Acute myocardial infarction within the previous 3 months.
• Acute exacerbation of asthma.
• Moderate to severe chronic obstructive pulmonary disease.
• Known allergy or hypersensitivity to any study anesthetic medication.
• Full-stomach status, intestinal obstruction, or gastric retention.
• Coagulation dysfunction or a clinically significant bleeding tendency.
• Mental illness or cognitive impairment that prevented cooperation with study procedures.