The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR


Registration number
ACTRN12612001007820
Ethics application status
Approved
Date submitted
13/09/2012
Date registered
19/09/2012
Date last updated
23/11/2018
Date data sharing statement initially provided
23/11/2018
Type of registration
Prospectively registered

Titles & IDs
Public title
The Effect of Changes in Cardiac Output on Sevoflurane Delivery in the Aisys Anaesthetic Machine.
Scientific title
The Effect of Changes in Cardiac Output on Sevoflurane Delivery in the Aisys Anaesthetic Machine in patients undergoing off-pump coronary artery bypass surgery (OPCAB).
Secondary ID [1] 281207 0
None
Universal Trial Number (UTN)
U1111-1134-5513
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Cardiac output changes during anaesthesia. 287395 0
Anaesthesia during off-pump coronary artery bypass surgery (OPCAB) 287426 0
Condition category
Condition code
Anaesthesiology 287737 287737 0 0
Anaesthetics
Cardiovascular 287758 287758 0 0
Coronary heart disease
Surgery 287759 287759 0 0
Other surgery

Intervention/exposure
Study type
Observational
Patient registry
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
An observational study to determine whether changes in anaesthetic agent delivery, using End-Tidal control (ETc), can be used as an indicator of cardiac output changes. We are monitoring changes in inspired concentration to determine whether these changes may provide an accurate indicator of cardiac output changes, before, during and immediately following periods of cardiac manipulation during OPCAB. We are particularly interested to see if monitoring the inspired concentration can detect cardiac output (CO) changes greater than 25%; that is, is there a given percentage fall in inspired sevoflurane that corresponds to a 25% drop in CO? This level of change is about the level of sensitivity of CO estimations using a pulmonary artery catheter and is frequently taken as the standard to which less invasive monitors should perform.
Since we are comparing time periods within single patient treatments, participants are their own control.
Intervention code [1] 285672 0
Not applicable
Comparator / control treatment
No control.
Control group
Uncontrolled

Outcomes
Primary outcome [1] 287984 0
To determine whether changes in anaesthetic agent delivery can be used as an indicator of cardiac output change during surgery.

Off-pump coronary artery bypass surgery is associated with abrupt changes in cardiac output (CO) as the heart is manipulated. We have observed that with end-tidal control, a feature of the Aisys anaesthetic machine, the target end-tidal level is well maintained but that there are significant changes in the rate of delivery seen with changes in CO. In particular, the inspired concentration now rises and falls in parallel with the end-tidal CO2. We are interested in determining whether there is a given percentage fall in inspired sevoflurane concentration that corresponds to a 25% drop in CO%. We will assess this by observing the Aisys monitor display and the Vigileo CO monitor display; by extracting and examining the data for each case from these machines and by comparing both sets of data against the relevant time periods.
Timepoint [1] 287984 0
5 minutes before and 1 minute after each manipulation of the heart during cororary artery bypass surgery.
Secondary outcome [1] 299213 0
Nil.
Timepoint [1] 299213 0
Nil.

Eligibility
Key inclusion criteria
Patients undergoing off-pump coronary artery bypass surgery (OPCAB) where the anaesthetic technique is based on sevoflurane and where use of flo trac/Vigileo monitors is not contra-indicated.
Minimum age
18 Years
Maximum age
No limit
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Aged <18 yrs;flo trac/Vigileo not required;

Study design
Purpose
Natural history
Duration
Cross-sectional
Selection
Defined population
Timing
Prospective
Statistical methods / analysis

Recruitment
Recruitment status
Stopped early
Data analysis
No data analysis planned
Reason for early stopping/withdrawal
Lack of funding/staff/facilities
Date of first participant enrolment
Anticipated
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment outside Australia
Country [1] 4547 0
New Zealand
State/province [1] 4547 0
Canterbury

Funding & Sponsors
Funding source category [1] 286011 0
Self funded/Unfunded
Name [1] 286011 0
Address [1] 286011 0
Country [1] 286011 0
Primary sponsor type
Individual
Name
Dr Frances Cammack
Address
Department of Anaesthesia,Christchurch Hospital
2 Riccarton Avenue
Christchurch 8011
Country
New Zealand
Secondary sponsor category [1] 284813 0
Individual
Name [1] 284813 0
Assoc Prof Dr Ross Kennedy
Address [1] 284813 0
Department of Anaesthesia,Christchurch Hospital
2 Riccarton Avenue
Christchurch 8011
Country [1] 284813 0
New Zealand
Secondary sponsor category [2] 284823 0
Individual
Name [2] 284823 0
Margie McKellow
Address [2] 284823 0
Department of Anaesthesia,Christchurch Hospital
2 Riccarton Avenue
Christchurch 8011
Country [2] 284823 0
New Zealand
Secondary sponsor category [3] 284824 0
Individual
Name [3] 284824 0
Dr Chris Harrison
Address [3] 284824 0
Department of Anaesthesia,Christchurch Hospital
2 Riccarton Avenue
Christchurch 8011
Country [3] 284824 0
New Zealand

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 288034 0
Southern Health and Disability Ethics Committee
Ethics committee address [1] 288034 0
Health and Disability Ethics Committee
PO Box 5013
Wellington 6154
Ethics committee country [1] 288034 0
New Zealand
Date submitted for ethics approval [1] 288034 0
08/06/2012
Approval date [1] 288034 0
18/07/2012
Ethics approval number [1] 288034 0
URA/12/06/024

Summary
Brief summary
Movement of gases (such as carbon dioxide or inhaled anaesthetic agents) that dissolve in the blood, in and out of the lungs, can indicate blood flow through the lungs. Because lung blood flow changes in parallel with cardiac output, we can measure the levels of these gases in the lungs to obtain information about cardiac output. It is already well known that expired CO2 levels change as cardiac output changes.

Our newest anaesthetic machines allow the user to set an expired concentration. The machine then adjusts delivery of the agent to maintain this expired level, with delivery increasing as uptake (& hence lung blood flow) increases and vice versa. We speculate that this system offers a unique opportunity to investigate the relationship between inhaled anaesthetic uptake and cardiac output.

During off-pump coronary artery bypass surgery (OPCAB), manipulation of the heart to access the various graft sites causes abrupt changes in cardiac output. These changes occur frequently during OPCAB surgery and produce visible changes in CO2 and anaesthetic agents levels. We monitor cardiac output during OPCAB with a device that provides a continuous measure of cardiac output based on the shape of the pulse waveform.

The combination of frequent large changes in cardiac output, a continuous measure of cardiac output and a new way to follow anaesthetic agent uptake gives us the opportunity to explore these relationships.
Trial website
NA
Trial related presentations / publications
Not yet.
Public notes

Contacts
Principal investigator
Name 34696 0
Dr Frances Cammack
Address 34696 0
Department of Anaesthesia
Christchurch Hospital
2 Riccarton Avenue
Christchurch 8011
Country 34696 0
New Zealand
Phone 34696 0
+64 (03) 3640288
Fax 34696 0
+64 (03) 3640289
Email 34696 0
francescammack@yahoo.com
Contact person for public queries
Name 17943 0
Mrs Margie McKellow
Address 17943 0
Department of Anaesthesia
Christchurch Hospital
2 Riccarton Avenue
Christchurch 8011
Country 17943 0
New Zealand
Phone 17943 0
+64 (03) 3640288
Fax 17943 0
+64 (03) 3640289
Email 17943 0
margie.mckellow@cdhb.govt.nz
Contact person for scientific queries
Name 8871 0
Dr Frances Cammack
Address 8871 0
Department of Anaesthesia
Christchurch Hospital
2 Riccarton Avenue
Christchurch 8011
Country 8871 0
New Zealand
Phone 8871 0
+64 (03) 3640288
Fax 8871 0
+64 (03) 3640289
Email 8871 0
francescammack@yahoo.com

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment
Study stopped early. Data collection/analysis not completed.
What supporting documents are/will be available?
No other documents available
Summary results
No Results