Blood isoflurane concentration and the oxygenator
Research type
Research Study
Full title
Does the type of oxygenator influence arterial blood concentration of isoflurane during cardiopulmonary bypass?
IRAS ID
215982
Contact name
R Peter Alston
Contact email
Sponsor organisation
University of Edinburgh
Duration of Study in the UK
0 years, 3 months, 27 days
Research summary
Cardiopulmonary bypass (CPB), more commonly known as a heart-lung machine, is a technique used in heart surgery to take over the role of the heart and lungs, allowing the surgeon access to a heart that isn’t beating. Whilst being an invaluable tool for heart surgery, CPB presents two challenges to providing anaesthesia. Firstly, CPB obscures clinical signs, such as heart rate and blood pressure, which are typically used to assess depth of anaesthesia. Secondly, ether-like anaesthetic are usually administered via the lungs, and this is impossible on CPB as the lungs are excluded from the blood stream.
In order to maintain anaesthesia during CPB, ether-like anaesthetic agents such as isoflurane, are given into the gas supply to the heart-lung machine. The gas supply is put into the oxygenator of the machine. Different types of oxygenators exist, and so may possess different transfer characteristics for anaesthetic agents – influencing the amount of isoflurane reaching the blood of the patient. These differences may not be seen clinically, but may be seen in differences of the arterial blood concentration of the anaesthetic.
This study aims to compare two oxygenators, both of which are currently in clinical use, to determine whether they affect the levels of isoflurane in the blood.
The participants will be recruited from adult patients scheduled to undergo heart surgery requiring CPB between January and March 2017 at the Royal Infirmary, Edinburgh. Patients will be randomised into either having one or other oxygenator used, and arterial blood samples will be taken at three different points during the surgery to determine concentration of anaesthetic agent in their blood. The levels will be compared statistically to determine if there is any difference as result of the oxygenator used.
REC name
South East Scotland REC 01
REC reference
16/SS/0216
Date of REC Opinion
15 Dec 2016
REC opinion
Favourable Opinion