Coronary sinus blood isoflurane concentration V 1.0
Research type
Research Study
Full title
Coronary sinus blood isoflurane concentration in patients undergoing heart surgery
IRAS ID
179348
Contact name
R Peter Alston
Contact email
Duration of Study in the UK
0 years, 4 months, 28 days
Research summary
Ether-like anaesthetics are commonly administered to patients supported on a heart-lung machine to maintain anaesthesia. A beneficial side effect of these anaesthetic agents is that they also improve outcome from heart surgery. Isoflurane is the most commonly used ether-like drug administered to patients on the heart-lung machine in the UK. However, the optimal dose of isoflurane in humans is unknown as there have been no measurements of its concentration in the heart muscle. A simple way to estimate the concentration of these drugs in the heart muscle is to measure the level in the main vein draining blood from the heart. Many surgeons routinely place a tube in this vein to administer solutions to stop the heart for surgery. The primary aim of this study is to sample blood from this vein using the tube the surgeon has placed and measure its concentration of isoflurane as an estimate of that in the heart muscle. A secondary aim is by measuring the concentration of the drug in arterial blood and by comparing it with the heart’s venous concentration, to determine whether the heart muscle level has stabilised before the heart is stopped. Another secondary aim is to determine whether measurement of the concentration of isoflurane being exhausted from the heart-lung machine could be used as a simple way to estimate the concentration in the venous blood draining from the heart.
Knowledge of the heart’s venous blood levels would be a basis for future studies to determine the dose of drug to administer to obtain the best outcome from heart surgery. If the concentration in the exhaust gases is an accurate estimate of the heart’s venous blood levels of isoflurane, then this technique could be used to titrate the amount administered to obtain the optimal patient outcome.REC name
North of Scotland Research Ethics Committee 1
REC reference
15/NS/0058
Date of REC Opinion
4 Aug 2015
REC opinion
Further Information Favourable Opinion