Estimating Blood Concentrations of Anaesthetics During One-Lung Ventilation (OLV)

Does the End-tidal Concentration Estimate the Blood Concentration of Inhalational Anaesthetics During One-lung Ventilation?

The aims of the study is to determine if end-tidal concentrations of the anaesthetic gases isoflurane and sevoflurane as measured by a standard gas monitor are related to the blood levels during one-lung ventilation.

Study Overview

• Status: Completed
• Conditions: One-Lung Ventilation
• Intervention / Treatment: Procedure: Lung Surgery with One-Lung Ventilation

Detailed Description

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.

Mechanically 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.

Patients 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.

• Study Type: Observational
• Enrollment (Actual): 19

Contacts and Locations

Study Locations

• United Kingdom
  • Edinburgh, United Kingdom, EH16 4SA
    • Royal Infirmary of Edinburgh

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients scheduled to undergo elective lung surgery with planned one-lung ventilation, identified from the operative list of a university hospital

Description

Inclusion Criteria:

• Over the age of 18
• Admitted for elective thoracic surgery using one-lung ventilation obtained by the use of a double-lumen endotracheal tube or bronchial blocker.
• Elective surgery planned between 1 August and 30 November 2016
• Planned insertion of an arterial cannula by anaesthetist for routine monitoring of systemic arterial pressure
• Planned inhalational anaesthesia technique with isoflurane or sevoflurane.
• Patients who have provided consent to take part in the study

Exclusion Criteria:

• Patients under the age of 18
• History of malignant hyperthermia
• Emergency thoracic surgery
• Patients who have not consented to take part in the study

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Lung Surgery with One-Lung Ventilation; A single cohort of patients undergoing one-lung ventilation during lung surgery	Procedure: Lung Surgery with One-Lung Ventilation; A single cohort of patients undergoing one-lung ventilation during lung surgery

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Correlation Between Blood and End-tidal Isoflurane or Sevoflurane Concentration During One-lung Ventilation	The significance of the correlation between blood and end-tidal isoflurane or sevoflurane concentration during one-lung ventilation	10 minutes after start of one-lung ventilation

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Correlation Between Bispectral Index (BIS) and End-tidal Isoflurane or Sevoflurane Concentration During One-lung Ventilation.	The significance of the correlation between BIS and end-tidal isoflurane or sevoflurane concentration during one-lung ventilation.	10 minutes after start of one-lung ventilation

Collaborators and Investigators

• Sponsor: University of Edinburgh
• Collaborators: NHS Lothian
• Investigators: Principal Investigator: R P Alston, MBChB,FRCA, University of Edinburgh

Study record dates

Study Major Dates

• Study Start: August 1, 2016
• Primary Completion (ACTUAL): November 1, 2016
• Study Completion (ACTUAL): January 1, 2017

Study Registration Dates

• First Submitted: June 29, 2016
• First Submitted That Met QC Criteria: June 29, 2016
• First Posted (ESTIMATE): July 1, 2016

Study Record Updates

• Last Update Posted (ACTUAL): August 2, 2018
• Last Update Submitted That Met QC Criteria: October 30, 2017
• Last Verified: October 1, 2017

More Information

Terms related to this study

• Keywords: Sevoflurane; Bispectral Index; Isoflurane; Pulmonary Surgical Procedures
• Other Study ID Numbers: AC16081

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO