Blood Propofol Measurement During Anaesthesia Using Propofol Target Controlled Infusion

Use of a Novel Point of Care Device to Measure Blood Propofol Levels During Propofol Based General Anesthesia by Target Controlled Infusion Using the Marsh Model in Effect Site Mode

Propofol is a commonly used agent for sedation and anaesthesia in the intensive care unit and the operating room. The pharmacokinetics of propofol are difficult to predict in patients not conforming to the norms in which the original pharmacokinetic research was based. Such patients, including the critically ill, and morbidly obese, are increasingly being encountered. The investigators group have been involved in the development of a device which can measure blood propofol concentrations, and hope for this to be available to use in the operating room in a clinically useful timeframe in the future. Data will be collected on patients undergoing propofol based general anaesthesia. The Marsh target controlled algorithm in effect site mode (commonly used by anaesthetists) will be assessed for accuracy using the propofol monitor. A new proportional correction method will be developed using this data, designed to enable recalibration of the TCI algorithm in near real time in order to achieve a more accurate estimated propofol concentration in these identified patient groups. The research will investigate the effectiveness of a correction of estimated propofol levels based on a one off measurement early on in the anaesthetic, and will take subsequent samples to measure propofol levels without modifying the TCI algorithm. Additionally, data on anaesthetist choice of TCI model, and method of administration in this relatively unselected group of patients will be analysed.

Study Overview

• Status: Completed
• Conditions: Pharmacokinetics; General Anaesthesia; Propofol; Target Controlled Infusion

• Study Type: Observational
• Enrollment (Actual): 50

Contacts and Locations

Study Locations

• United Kingdom
  • West Midlands
    • Birmingham, West Midlands, United Kingdom, B15 2TH
      • University Hospitals Birmingham NHS Foundation Trust

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 16 years and older (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients treated in the Operating Theatre undergoing propofol intravenous anaesthesia who require an arterial line to be inserted as standard care.

Description

Inclusion Criteria:

• Only patients undergoing major surgery where blood sampling through arterial or central venous catheters is part of their routine clinical care will be recruited.
• Only patients undergoing total intravenous anaesthesia using propofol will be recruited.

Exclusion Criteria:

• Anaemic patients will not be recruited into the study.
• Patients unable to consent will not be recruited into the study.

Study Plan

How is the study designed?

Design Details

• Observational Models: Case-Only
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort
General Anaesthesia; Patients undergoing general anaesthesia using Marsh model target controlled infusion in effect site mode.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Median percentage prediction error of estimated propofol concentration compared to measured concentrations (Bias)	duration of anaesthesia (up to 24 hours)

Secondary Outcome Measures

Outcome Measure	Time Frame
Median absolute percentage prediction error of estimated propofol concentration compared to measured concentrations (inaccuracy)	duration of anaesthesia (up to 24 hours)
Change in median percentage prediction error(bias)for propofol levels measured beyond thirty minutes following proportional correction at thirty minutes	thirty minutes

Collaborators and Investigators

• Sponsor: University Hospital Birmingham NHS Foundation Trust
• Investigators: Principal Investigator: Nicholas J Cowley, MRCP FRCA, University Hospital Birmingham NHS Foundation Trust; Study Chair: Thomas Clutton-Brock, FRCA FRCP, University Hospital Birmingham NHS Foundation Trust

Study record dates

Study Major Dates

• Study Start: January 1, 2012
• Primary Completion (Actual): June 1, 2012
• Study Completion (Actual): June 1, 2012

Study Registration Dates

• First Submitted: March 2, 2012
• First Submitted That Met QC Criteria: March 6, 2012
• First Posted (Estimate): March 9, 2012

Study Record Updates

• Last Update Posted (Estimate): July 19, 2012
• Last Update Submitted That Met QC Criteria: July 18, 2012
• Last Verified: July 1, 2012

More Information

Terms related to this study

• Keywords: Propofol; General anaesthesia; Target controlled infusion
• Other Study ID Numbers: rrk4342

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No