Afentanil and Remifentanil for Anesthesia Quality and Recovery

Summary

The goal of this clinical trial is to compare two commonly used opioid pain medications-alfentanil and remifentanil-during general anesthesia for surgery, and to find out whether alfentanil is as good as (not worse than) remifentanil in keeping patients stable (steady blood pressure and heart rate) and adequately pain-free during the operation. The study will enroll adults aged 18-65 years who are in good to fair health (ASA class I-III) and are scheduled for elective non-cardiac, non-brain surgery lasting 1 to 4 hours with expected blood loss under 500 mL.

The main questions it aims to answer are:

How often do patients need extra painkillers or blood-pressure medications during surgery (a "rescue event") when receiving alfentanil compared with remifentanil?

How quickly do patients wake up, breathe on their own, and get discharged from the recovery room after the operation?

Do patients experience differences in pain levels, nausea, vomiting, or thinking/memory problems in the days after surgery?

If there is a comparison group: Researchers will compare the alfentanil group with the remifentanil group to see if the rate of rescue events with alfentanil is not more than 8% higher than with remifentanil (the non-inferiority margin). Both groups will receive the same standard anesthetic (propofol and muscle relaxants) and the same postoperative pain management; only the study opioid differs.

Participants will:

Sign an informed consent form and undergo screening tests, including blood work, physical exam, and medical history review.

Be randomly assigned (like a coin flip) to receive either alfentanil or remifentanil during their operation, with the drug given through an IV. Neither the patient nor the care team will know which drug is given until after the study is completed.

Have their blood pressure, heart rate, breathing, and brain activity (using BIS monitors to measure depth of anesthesia) continuously tracked during surgery.

After surgery, be followed for up to 3 days, during which they will be asked to rate their pain (using a simple 0-10 scale) and complete a short memory/thinking test (MMSE) at set times.

Provide small blood samples before, right after, and 24 hours after surgery to measure stress hormones and inflammation markers.

This study will involve about 990 patients across multiple hospitals and will take about 2 years to complete. The results will help doctors choose the best opioid for safer, smoother surgeries and faster recovery.

Conditions

• Anesthesia Recovery Period ； Postoperative Pain； Hemodynamic Stability During Surgery

Interventions

DRUG

alfentanil

Alfentanil Hydrochloride Injection is administered intravenously for induction of general anesthesia at a single bolus dose of 30 μg/kg over 30 seconds, followed by a continuous intravenous infusion at a maintenance rate of 0.5-2.0 μg/kg/min, titrated stepwise by 0.3 μg/kg/min increments based on predefined hemodynamic triggers (heart rate or systolic blood pressure increase \>20% from baseline). The infusion is continued throughout surgery and discontinued precisely upon completion of skin closure. All participants in this arm also receive standardized propofol (via target-controlled infusion, Schnider model, Ce 2.5-3.5 μg/mL, BIS-guided 40-60), rocuronium for neuromuscular blockade, and uniform postoperative transitional analgesia (sufentanil 0.1 μg/kg IV) followed by patient-controlled intravenous analgesia (PCIA) with sufentanil/nalbuphine/ondansetron. The opioid infusion is the only differentiating factor between study arms

DRUG

Remifentanil

Remifentanil Hydrochloride Injection is administered intravenously for induction at a single bolus dose of 1 μg/kg over 30 seconds, followed by a continuous infusion at 0.1-0.3 μg/kg/min during maintenance, titrated by 0.05 μg/kg/min increments using the same hemodynamic criteria. All other anesthetic, adjunctive, and postoperative analgesic regimens are identical to those in the alfentanil arm.

Sponsors & Collaborators

• Qianfoshan Hospital

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

65 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2026-09-01

Primary Completion

2027-06-30

Completion

2027-09-30

FDA Drug

Yes