Remifentanil dosing and clearance in low-weight ICU patients

Population Pharmacokinetics of Remifentanil for Analgesia and Sedation in Low-Weight Critically Ill Patients Receiving Mechanical Ventilation

This study will test how remifentanil is processed in the body and how it affects blood pressure and sedation in low-body-weight adults on mechanical ventilation in the ICU.

Quick facts

• Study type: Observational
• Enrollment: 45 (estimated)
• Sex: All
• Sponsor: Fudan University (other)
• Locations: 1 site (Shanghai)
• Trial ID: NCT07301970 on ClinicalTrials.gov

What this trial studies

This is a prospective, single-center observational study enrolling adult ICU patients receiving invasive mechanical ventilation who are given remifentanil for analgosedation under a standardized clinical protocol. Researchers will collect arterial blood samples at predefined time points to measure remifentanil concentrations and construct a population pharmacokinetic (PopPK) model. Hemodynamic parameters and sedation adequacy will be recorded continuously, and a subset of patients receiving propofol as rescue sedation will have plasma propofol measured to evaluate its impact on blood pressure. The goal is to relate PK parameters to safety (hemodynamic stability) and sedation outcomes in low-body-weight critically ill patients.

Who should consider this trial

Good fit: Adults (≥18 years) with low or normal BMI who are admitted to the ICU, require invasive mechanical ventilation for more than 10 hours, and (or whose legal guardian) can provide informed consent are the intended participants.

Not a fit: Pregnant patients, those with severe respiratory depression during screening, known hypersensitivity to remifentanil, or other contraindications to opioid use are excluded and unlikely to receive direct benefit from participation.

Why it matters

Potential benefit: If successful, the results could help clinicians dose remifentanil more safely and effectively for low-weight ICU patients, potentially reducing blood-pressure-related complications and improving sedation control.

How similar studies have performed: Remifentanil's pharmacokinetics and clinical effects are well documented in surgical and general ICU populations, but dedicated population PK studies focused specifically on low-weight critically ill adults are limited.

Eligibility criteria

Inclusion Criteria:

* Age: ≥18 years old, regardless of sex;
* Normal weight: 18.5 kg/m² ≤ Body Mass Index (BMI) \< 24 kg/m² or Low weight: BMI \< 18.5 kg/m²;
* Admitted to the intensive care unit (ICU);
* Required invasive mechanical ventilation for more than 10 hours;
* The subject or their legal guardian has fully understood the potential risks and benefits of participating in this study and has signed the informed consent form.

Exclusion Criteria:

* Pregnant women;
* Presence of severe respiratory impairment or respiratory depression during the screening period;
* Known hypersensitivity to remifentanil or any of the excipients;
* Meeting other contraindications for opioid use

Where this trial is running

Shanghai

• Shanghai Minhang Central Hospital — Shanghai, China (RECRUITING)

Study contacts

• Principal investigator: Xiang Li — Shanghai Minhang Central Hospital
• Study coordinator: Xiang Li

Conditions: Critical Illness, Pain