Clinical trial NCT01549639: Blood Propofol Measurement During Anaesthesia Using Propofol Target Controlled Infusion
Official title: 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
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: General Anaesthesia
Propofol
Target Controlled Infusion
Pharmacokinetics
Keywords: Propofol
Target controlled infusion
General anaesthesia
Lead sponsor: University Hospital Birmingham NHS Foundation Trust
Sponsor class: OTHER
First posted: 2012-03-09
Enrollment: 50
Sex: ALL
Minimum age (years): 16
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_ONLY
Time perspective: PROSPECTIVE
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.

Brief summary: 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.


Eligibility criteria: 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.

Primary outcomes:
measure: Median percentage prediction error of estimated propofol concentration compared to measured concentrations (Bias)
timeFrame: duration of anaesthesia (up to 24 hours)
Secondary outcomes:
measure: Median absolute percentage prediction error of estimated propofol concentration compared to measured concentrations (inaccuracy)
timeFrame: duration of anaesthesia (up to 24 hours)
measure: Change in median percentage prediction error(bias)for propofol levels measured beyond thirty minutes following proportional correction at thirty minutes
timeFrame: thirty minutes
Other outcomes:
Locations:
city: Birmingham
country: United Kingdom
facility: University Hospitals Birmingham NHS Foundation Trust
state: West Midlands
Study officials:
affiliation: University Hospital Birmingham NHS Foundation Trust
name: Nicholas J Cowley, MRCP FRCA
role: PRINCIPAL_INVESTIGATOR
affiliation: University Hospital Birmingham NHS Foundation Trust
name: Thomas Clutton-Brock, FRCA FRCP
role: STUDY_CHAIR
References: