Estimating blood concentrations of anaesthetics during OLV
Research type
Research Study
Full title
Does the end-tidal concentration estimate the blood concentration of inhalational anaesthetics during one-lung ventilation?
IRAS ID
206006
Contact name
R Peter Alston
Contact email
Sponsor organisation
University of Edinburgh
Duration of Study in the UK
0 years, 3 months, 30 days
Research summary
Measurement of the anaesthetic gases such as isoflurane and sevoflurane allow anaesthetists to gauge their blood levels and in turn their brain levels and so help assess how deep the patient is under anaesthesia. These measurements, made as the patient breathes out, are known as end-tidal concentrations of anesthetic gases and are routinely made with gas monitors. Measurement of blood levels of anaesthetic gases is possible but infrequently done as it is time-consuming, expensive, and requires a scientist in a laboratory with specialized equipment. Depth of anaesthesia is assessed using clinical signs along with end-tidal concentrations though more recently it can be assessed by monitoring the brain’s electrical waves. This technique remains controversial. \n\n\nMechanically supporting the patient’s breathing using only one of the two lungs, known as one-lung ventilation, is used in lung surgery to allow the surgeon to gain access to one side of the chest whilst the anaesthetist supports the lung on the other side. One-lung ventilation markedly alters the exchange of gases in the lungs, including anaesthetic gases. Because of this derangement, it is not known if the end-tidal concentrations are related to blood levels of anaesthetic gases during this type of mechanical ventilation. The aims of the study is to determine if end-tidal concentrations of anaesthetics as measured by a standard gas monitor are related to the blood levels of the gases isoflurane and sevoflurane during one-lung ventilation. \n\n\nPatients over 18 years old undergoing planned lung surgery with one-lung ventilation and anaesthesia with isoflurane or sevoflurane, and who have a routine tube inserted into an artery in their wrist to monitor blood pressure will be recruited for the study. During the study, two blood samples the size of two teaspoons each will be taken from the tube in the artery and two end-tidal concentration recordings.
REC name
North West - Preston Research Ethics Committee
REC reference
16/NW/0550
Date of REC Opinion
18 Jul 2016
REC opinion
Favourable Opinion