ANZCTR - Registration

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Trial registered on ANZCTR

Registration number

ACTRN12613001322729

Ethics application status

Approved

Date submitted

27/11/2013

Date registered

28/11/2013

Date last updated

5/01/2017

Type of registration

Prospectively registered

Titles & IDs

Public title

Evaluation of the introduction of conservative oxygen therapy compared to normal oxygen therapy practice in patients undergoing cardiac surgery: A before and after audit

Scientific title

Evaluation of a change in PaO2/FiO2 ratio following the introduction of conservative oxygen therapy compared to normal oxygen therapy practice in patients undergoing cardiac surgery: A before and after audit

Secondary ID [1]

Nil

Universal Trial Number (UTN)

Trial acronym

Linked study record

Health condition

Health condition(s) or problem(s) studied:

Patients undergoing cardiac surgery

Peri-operative change in oxygen therapy management

Condition category

Condition code

Anaesthesiology

Other anaesthesiology

Surgery

Other surgery

Cardiovascular

Coronary heart disease

Intervention/exposure

Study type

Observational

Patient registry

False

Target follow-up duration

Target follow-up type

Description of intervention(s) / exposure

Conservative oxygen therapy involves the deliberate manipulation of fraction of inspired oxygen (FiO2) concentration to achieve normal blood oxygen saturations (pulse oximetry derived oxygen saturation 94-98%) during mechanical ventilation with an endotracheal tube. Data will be extracted from the medical records of 100 consecutive cardiac surigcal patients commencing in December 2013.

Intervention code [1]

Not applicable

Comparator / control treatment

Patient in the before period will have recieved oxygen therapy to target oxygen saturations prior to, during and after surgery as determined by their treating clinicians. Data will be extracted from the medical records of 100 consecutive cardiac surigcal patients prior to November 2013.

Control group

Historical

Outcomes

Primary outcome [1]

Change in PaO2/FIO2 ratio.

Timepoint [1]

Assessment of arterial blood gas data obtained prior to, during and while the patient is mechanically ventiled in the intensive care unit following their cardiac surgical procedure.

Secondary outcome [1]

Blood lactate levels

Timepoint [1]

At baseline (prior to surgery) to highest value for 7 days after cardiac surgery

Secondary outcome [2]

Change in blood creatinine

Timepoint [2]

At baseline (prior to surgery) to highest value for 7 days after cardiac surgery

Secondary outcome [3]

New non-respiratory organ failure

Timepoint [3]

While in ICU and defined as Sequential Organ Failure Assessment (SOFA) score of at least 3 for any of the cardiovascular, renal, hepatic, or hematological systems after day 2 in patients who did not have such organ failure at day 1 for up to 7 days while in the intensive care unit

Secondary outcome [4]

Arrhythmia

Timepoint [4]

At baseline (prior to surgery) to discharge from the intensive care unit as determined by ECG monitoring and documentation of cardiac rhythm type on the patient's observation charts.

Secondary outcome [5]

Infection

Timepoint [5]

Defined as a positive bacterial culture in sputum, urine or blood from samples collected between baseline (prior to surgery) to discharge from the intensive care unit

Secondary outcome [6]

severe hypoxaemia

Timepoint [6]

Defined as an arterial oxygen concentration less than 55 mmHg from baseline (prior to surgery) to discharge from the intensive care unit

Secondary outcome [7]

acquired renal replacement therapy

Timepoint [7]

Defined as the commencement of renal replacement therapy 24 hours after enrolment and discharge from the intensive care unit

Secondary outcome [8]

anti-delirium drug use

Timepoint [8]

Defined as the use of Haloperidol, Olanzapine, Quetiapine and Dexmedetomidine from baseline (prior to surgery) to discharge from the intensive care unit

Secondary outcome [9]

Red blood cell tranfusion

Timepoint [9]

From baseline (prior to surgery) to discharge from the intensive unit

Secondary outcome [10]

Intensive care unit free days

Timepoint [10]

From baseline to day 28

Secondary outcome [11]

Hospital free days

Timepoint [11]

From baseline to day 28

Secondary outcome [12]

Mortality

Timepoint [12]

At day 28 from baseline

Eligibility

Key inclusion criteria

Cardiac surgery

Minimum age

18 Years

Maximum age

90 Years

Sex

Both males and females

Can healthy volunteers participate?

Key exclusion criteria

- pregnancy
- less than 18 years of age
- receiving extra-corporeal membrane oxygenation (ECMO)
- death expected within 24 hours

Study design

Purpose

Screening

Duration

Longitudinal

Selection

Convenience sample

Timing

Both

Statistical methods / analysis

Variables will be assessed for normality and log-transformed if appropriate. Baseline comparisons will be performed using Fisher’s exact tests and reported as n (%). Continuous normally distributed variables will be compared using Student t-tests and reported as means (standard deviation), while non-normally distributed data will be compared using Wilcoxon rank-sum tests and reported as medians [interquartile range]. Changes over time will be determined using repeated measures mixed linear modeling with each patient treated as a random effect, and therapy group, time and the interaction of therapy group and time as effect fixed effects. All analysis will be performed by using SPSS version 19.0 (SPSS Inc, Chicago, IL, USA). To account for multiple comparisons and further reduce the chance of a type I error, a two-sided p value of 0.01 was used to indicate statistical significance.

Recruitment

Recruitment status

Completed

Date of first participant enrolment

Anticipated

1/12/2013

Actual

27/03/2015

Date of last participant enrolment

Anticipated

Actual

27/04/2015

Date of last data collection

Anticipated

Actual

18/09/2016

Sample size

Target

200

Accrual to date

Final

546

Recruitment in Australia

Recruitment state(s)

VIC

Recruitment hospital [1]

Austin Health - Austin Hospital - Heidelberg

Recruitment postcode(s) [1]

3084 - Heidelberg

Funding & Sponsors

Funding source category [1]

Hospital

Name [1]

Anaesthesia Intensive Care Trust Fund, Austin Hospital

Address [1]

c/o Department of Intensive Care
Austin Hospital
145 Studley Road
Heidelberg VIC 3084

Country [1]

Australia

Primary sponsor type

Hospital

Name

Austin Health

Address

Austin Hospital
145 Studley Road
Heidelberg VIC 3084

Country

Australia

Secondary sponsor category [1]

None

Name [1]

Address [1]

Country [1]

Ethics approval

Ethics application status

Approved

Ethics committee name [1]

Austin Health Human Research Ethics Committee

Ethics committee address [1]

c/o Office for Research
Austin Hospital
145 Studley Road
Heidelberg VIC 3084

Ethics committee country [1]

Australia

Date submitted for ethics approval [1]

Approval date [1]

27/08/2013

Ethics approval number [1]

HREC/13/Austin/100

Summary

Brief summary

Cardiac surgical patients routinely receive supplemental oxygen immediately prior to, during and immediately following their cardiac surgical procedure.  A major goal of anaesthetic care of the cardiac surgical patient is the maintenance of haemodynamic stability as well as the preservation of myocardial and systemic tissue oxygenation.  Often cardiac surgical patients will receive supplemental oxygen and have supra-normal concentration of oxygen as a buffer of safety (Ihnken et al., 1998).  However, cardiac surgical patients are particular susceptible to lung and myocardial injury attributable to hyperoxic states.  Reactive oxygen species (ROS) are well known for their role in myocardial injury.  ROS are free radicals (unpaired electrons) involved with oxidation-reduction reactions with other molecules.   During cardiac surgery the formation of oxygen free radicals is accelerated from tissue injury and the use of cardiopulmonary bypass.  Clinical studies have demonstrated apoptosis and deoxyribonucleic acid (DNA) fragmentation occurring after ischemia-reperfusion injury.  In addition, prolonged high oxygen concentrations have been shown to decrease myocardial contractility and a decrease in heart rate which results in impaired cardiac function and may delay recovery (Joachimsson et al, 1996; Ihnken et al, 1998).

The aim of this study is to evaluate the impact of a peri-operative change in oxygen therapy management for cardiac surgical patients based on emerging evidence.

The change involved the adoption of a conservative oxygen therapy approach to oxygen therapy management during the perio-operative period.  Conservatiive oxygen therapy is  involves the deliberate manipulation of fraction of inspired oxygen (FiO2) concentration to achieve normal blood oxygen saturations.

We plan to inlcude 100 cardiac surgical patients in the before period and 100 cardiac surgical patients in the after period.

Trial website

Trial related presentations / publications

Publication: Suzuki S, Eastwood GM, Glassford NJ, Peck L, Young H, Garcia-Alvarez M, Schneider AG, Bellomo R. Conservative Oxygen Therapy In Mechanically Ventilated Pateints: A Pilot Before-and-After Trial. Crit Care Med. 2014 June;42(6):1414-22.

Public notes

Attachments [1]

/AnzctrAttachments/365379-Satoshi et al_Conservative oxygen therapy in MC patients_a pilot before-after trial_CCM_2014_epub.pdf

Contacts

Principal investigator

Name

Prof Rinaldo Bellomo

Address

Department of Intensive Care
Austin Hospital
145 Studley Road
Heidelberg VIC 3084

Country

Australia

Phone

+61 3 9496 5992

Fax

+61 3 9496 3932

[email protected]

Contact person for public queries

Name

Glenn Eastwood

Address

Department of Intensive Care
Austin Hospital
145 Studley Road
Heidelberg VIC 3084

Country

Australia

Phone

+61 3 9496 4835

Fax

+ 61 3 9496 3932

[email protected]

Contact person for scientific queries

Name

Rinaldo Bellomo

Address

Department of Intensive Care
Austin Hospital
145 Studley Road
Heidelberg VIC 3084

Country

Australia

Phone

+ 61 3 9496 5992

Fax

+61 3 9496 3932

[email protected]

No information has been provided regarding IPD availability

What supporting documents are/will be available?

No Supporting Document Provided

Results publications and other study-related documents

Documents added manually

No documents have been uploaded by study researchers.

Documents added automatically

Source	Title	Year of Publication	DOI
Dimensions AI	Conservative versus conventional oxygen therapy for cardiac surgical patients: A before-and-after study	2019	https://doi.org/10.1177/0310057x19838753

N.B. These documents automatically identified may not have been verified by the study sponsor.

Trial Review

Documents added manually

Documents added automatically