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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] 283655 0
Nil
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Patients undergoing cardiac surgery 290606 0
Peri-operative change in oxygen therapy management 290607 0
Condition category
Condition code
Anaesthesiology 290996 290996 0 0
Other anaesthesiology
Surgery 291003 291003 0 0
Other surgery
Cardiovascular 291004 291004 0 0
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] 288357 0
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] 290976 0
Change in PaO2/FIO2 ratio.
Timepoint [1] 290976 0
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] 305715 0
Blood lactate levels
Timepoint [1] 305715 0
At baseline (prior to surgery) to highest value for 7 days after cardiac surgery
Secondary outcome [2] 305716 0
Change in blood creatinine
Timepoint [2] 305716 0
At baseline (prior to surgery) to highest value for 7 days after cardiac surgery
Secondary outcome [3] 305717 0
New non-respiratory organ failure
Timepoint [3] 305717 0
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] 305718 0
Arrhythmia
Timepoint [4] 305718 0
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] 305719 0
Infection
Timepoint [5] 305719 0
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] 305720 0
severe hypoxaemia
Timepoint [6] 305720 0
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] 305721 0
acquired renal replacement therapy
Timepoint [7] 305721 0
Defined as the commencement of renal replacement therapy 24 hours after enrolment and discharge from the intensive care unit
Secondary outcome [8] 305722 0
anti-delirium drug use
Timepoint [8] 305722 0
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] 305723 0
Red blood cell tranfusion
Timepoint [9] 305723 0
From baseline (prior to surgery) to discharge from the intensive unit
Secondary outcome [10] 305724 0
Intensive care unit free days
Timepoint [10] 305724 0
From baseline to day 28
Secondary outcome [11] 305725 0
Hospital free days
Timepoint [11] 305725 0
From baseline to day 28
Secondary outcome [12] 305726 0
Mortality
Timepoint [12] 305726 0
At day 28 from baseline

Eligibility
Key inclusion criteria
Cardiac surgery
Minimum age
18 Years
Maximum age
90 Years
Gender
Both males and females
Can healthy volunteers participate?
No
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
Actual
Date of last participant enrolment
Anticipated
Actual
Date of last data collection
Anticipated
Actual
Sample size
Target
Accrual to date
Final
Recruitment in Australia
Recruitment state(s)
VIC
Recruitment hospital [1] 1768 0
Austin Health - Austin Hospital - Heidelberg
Recruitment postcode(s) [1] 7585 0
3084 - Heidelberg

Funding & Sponsors
Funding source category [1] 288335 0
Hospital
Name [1] 288335 0
Anaesthesia Intensive Care Trust Fund, Austin Hospital
Address [1] 288335 0
c/o Department of Intensive Care
Austin Hospital
145 Studley Road
Heidelberg VIC 3084
Country [1] 288335 0
Australia
Primary sponsor type
Hospital
Name
Austin Health
Address
Austin Hospital
145 Studley Road
Heidelberg VIC 3084
Country
Australia
Secondary sponsor category [1] 287051 0
None
Name [1] 287051 0
Address [1] 287051 0
Country [1] 287051 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 290228 0
Austin Health Human Research Ethics Committee
Ethics committee address [1] 290228 0
c/o Office for Research
Austin Hospital
145 Studley Road
Heidelberg VIC 3084
Ethics committee country [1] 290228 0
Australia
Date submitted for ethics approval [1] 290228 0
Approval date [1] 290228 0
27/08/2013
Ethics approval number [1] 290228 0
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

Contacts
Principal investigator
Name 44574 0
Prof Rinaldo Bellomo
Address 44574 0
Department of Intensive Care
Austin Hospital
145 Studley Road
Heidelberg VIC 3084
Country 44574 0
Australia
Phone 44574 0
+61 3 9496 5992
Fax 44574 0
+61 3 9496 3932
Email 44574 0
rinaldo.bellomo@austin.org.au
Contact person for public queries
Name 44575 0
Dr Glenn Eastwood
Address 44575 0
Department of Intensive Care
Austin Hospital
145 Studley Road
Heidelberg VIC 3084
Country 44575 0
Australia
Phone 44575 0
+61 3 9496 4835
Fax 44575 0
+ 61 3 9496 3932
Email 44575 0
glenn.eastwood@austin.org.au
Contact person for scientific queries
Name 44576 0
Prof Rinaldo Bellomo
Address 44576 0
Department of Intensive Care
Austin Hospital
145 Studley Road
Heidelberg VIC 3084
Country 44576 0
Australia
Phone 44576 0
+ 61 3 9496 5992
Fax 44576 0
+61 3 9496 3932
Email 44576 0
rinaldo.bellomo@austin.org.au

No information has been provided regarding IPD availability
Summary results
Have study results been published in a peer-reviewed journal?
Other publications
Have study results been made publicly available in another format?
Results – basic reporting
Results – plain English summary