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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Date data sharing statement initially provided
Date results information initially provided
Type of registration
Prospectively registered

Titles & IDs
Public title
Airway Pressure Release Ventilation for mechanically ventilated patients with COVID-19 in Western Australian Intensive Care Units: an observational study
Scientific title
West Australian Airway Pressure Release Ventilation Study in COVID-19: evaluation of ventilation free survival days
Secondary ID [1] 300987 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
COVID-19 (SARS-CoV2) 317022 0
Condition category
Condition code
Infection 315187 315187 0 0
Other infectious diseases
Respiratory 315188 315188 0 0
Other respiratory disorders / diseases

Study type
Patient registry
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
Airway pressure release ventilation has traditionally been used as a rescue mode of mechanical ventilation for patients with ARDS (acute respiratory distress syndrome), however it may also be beneficial early on in ARDS. It helps with recruitment (opening up) of lungs by having a continuous high level of positive pressure and timed pressure release. Spontaneous breathing is still possible.
The mode of ventilation provided to patients is chosen at the discretion of the treating clinician. Mode of mechanical ventilation received by intubated patients in ICU is being observed from intubation until extubated.
Intervention code [1] 317309 0
Not applicable
Comparator / control treatment
The mode of mechanical ventilation provided to a patient is chosen by the treating clinician. The different modes of ventilation manipulate different parts of the breathing cycle, either focused on using pressure to deliver a breath (pressure controlled ventilation), or delivering a designated volume (spontaneous intermittent mandatory ventilation (SIMV)), or supporting a spontaneous breathing patient (pressure support),
Control group

Primary outcome [1] 323444 0
Ventilation free survival days as assessed by reviewing medical records
Timepoint [1] 323444 0
At 90 days after initiation of mechanical ventilation
Secondary outcome [1] 381965 0
Change in P/F ratio after initiation of mechanical ventilation as assessed by arterial blood gas result and medical record of FiO2 delivered on ventilator
Timepoint [1] 381965 0
At 1, 3 and 7 days.
Secondary outcome [2] 381966 0
Complications from mode of ventilation (pneumothorax) as assessed by review of radiology reports and medical records
Timepoint [2] 381966 0
Any time during mechanical ventilation
Secondary outcome [3] 381967 0
ICU length of stay
Timepoint [3] 381967 0
Assessed up to 90 days post enrolment
Secondary outcome [4] 381968 0
Hospital length of stay
Timepoint [4] 381968 0
Assessed at 90 days post enrolment
Secondary outcome [5] 381969 0
Timepoint [5] 381969 0
Any time up to 90 days post enrolment

Key inclusion criteria
Mechanically ventilated
COVID-19 positive
Admitted to Intensive Care Unit in participating Western Australian ICU
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria

Study design
Natural history
Defined population
Statistical methods / analysis
The Murray Lung Injury score will be used to match patients, and compare the APRV and non-APRV groups. The primary outcome will focus on ventilation-free survival days (within 90 days) between those with and without APRV adjusted for time to initiate APRV (or death / day 90 for those without APRV) from admission to ICU. If sample size allows, further adjustment for baseline characteristics, such as the APACHE score and PaO2/FiO2 ratio, of the two groups will be conducted.
Subgroup analysis will be performed according to 1) ARDS severity 2) early initiation of APRV (within 24 hours of initiation of mechanical ventilation), versus late initiation (after 24 hours of mechanical ventilation)

Recruitment status
Active, not recruiting
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment hospital [1] 16416 0
Sir Charles Gairdner Hospital - Nedlands
Recruitment hospital [2] 16417 0
Royal Perth Hospital - Perth
Recruitment hospital [3] 16418 0
Fiona Stanley Hospital - Murdoch
Recruitment hospital [4] 16419 0
Armadale Kelmscott Memorial Hospital - Armadale
Recruitment hospital [5] 16420 0
Rockingham General Hospital - Cooloongup
Recruitment hospital [6] 16421 0
Bunbury Hospital - Bunbury
Recruitment hospital [7] 16422 0
St John of God Midland Public Hospital - Midland
Recruitment hospital [8] 16423 0
Joondalup Health Campus - Joondalup
Recruitment postcode(s) [1] 29960 0
6009 - Nedlands
Recruitment postcode(s) [2] 29961 0
6000 - Perth
Recruitment postcode(s) [3] 29962 0
6150 - Murdoch
Recruitment postcode(s) [4] 29963 0
6112 - Armadale
Recruitment postcode(s) [5] 29964 0
6168 - Cooloongup
Recruitment postcode(s) [6] 29965 0
6230 - Bunbury
Recruitment postcode(s) [7] 29966 0
6056 - Midland
Recruitment postcode(s) [8] 29967 0
6027 - Joondalup

Funding & Sponsors
Funding source category [1] 305433 0
Name [1] 305433 0
Sir Charles Gairdner Hospital
Address [1] 305433 0
Hospital Avenue
Nedlands 6009, Western Australia
Country [1] 305433 0
Funding source category [2] 306773 0
Government body
Name [2] 306773 0
WA Health
Address [2] 306773 0
189 Royal St
East Perth 6004, Western Australia
Country [2] 306773 0
Primary sponsor type
Sir Charles Gairdner Hospital
Hospital Avenue
Nedlands 6009, WA
Secondary sponsor category [1] 305827 0
Name [1] 305827 0
Address [1] 305827 0
Country [1] 305827 0

Ethics approval
Ethics application status
Ethics committee name [1] 305752 0
Sir Charles Gairdner and Osborne Park Health Care Group Human Research Ethics Committee
Ethics committee address [1] 305752 0
A Block, Sir Charles Gairdner Hospital
Hospital Avenue
Nedlands, 6009, Western Australia
Ethics committee country [1] 305752 0
Date submitted for ethics approval [1] 305752 0
Approval date [1] 305752 0
Ethics approval number [1] 305752 0
RGS 4003
Ethics committee name [2] 305782 0
Ramsay Health Care WA|SA HREC
Ethics committee address [2] 305782 0
Joondalup Health Campus
Grand Blvd &, Shenton Ave, Joondalup WA 6027
Ethics committee country [2] 305782 0
Date submitted for ethics approval [2] 305782 0
Approval date [2] 305782 0
Ethics approval number [2] 305782 0
Ethics committee name [3] 305783 0
St John of God Health Care Human Research Ethics Committee
Ethics committee address [3] 305783 0
C/o St John of God Subiaco Hospital
12 Salvado Road
Subiaco Western Australia 6008
Ethics committee country [3] 305783 0
Date submitted for ethics approval [3] 305783 0
Approval date [3] 305783 0
Ethics approval number [3] 305783 0

Brief summary
Prior research has suggested that in adult patients requiring mechanical ventilation for hypoxic respiratory failure, that airway pressure release ventilation (APRV) is associated with a mortality benefit and improved oxygenation when compared to conventional ventilation strategies. The Western Australian Intensive Care clinical community has extensive experience with APRV, including during the H1N1 epidemic. The aim of this observational study is to record the outcomes for mechanically ventilated patients with COVID-19, with the expectation that a significant proportion of WA intensive care clinicians will choose APRV. Analysis will compare APRV with non-APRV ventilation modes.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 101470 0
A/Prof Matthew Anstey
Address 101470 0
c/ Intensive Care Department
G Block, 4th Floor
Hospital Avenue,
Sir Charles Gairdner Hospital
Nedlands 6009, WA
Country 101470 0
Phone 101470 0
+61 0409124876
Fax 101470 0
Email 101470 0
Contact person for public queries
Name 101471 0
A/Prof Matthew Anstey
Address 101471 0
c/ Intensive Care Department
G Block, 4th Floor
Hospital Avenue,
Sir Charles Gairdner Hospital
Nedlands 6009, WA
Country 101471 0
Phone 101471 0
+61 0409124876
Fax 101471 0
Email 101471 0
Contact person for scientific queries
Name 101472 0
A/Prof Matthew Anstey
Address 101472 0
c/ Intensive Care Department
G Block, 4th Floor
Hospital Avenue,
Sir Charles Gairdner Hospital
Nedlands 6009, WA
Country 101472 0
Phone 101472 0
+61 0409124876
Fax 101472 0
Email 101472 0

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
What data in particular will be shared?
The investigators will be the custodians of the final trial dataset. No-one outside the trial steering committee will be given access to the data without the permission of the trial steering committee. De-identified data (individual participant data of published results only) may be made available after request to the investigators , with approval of the site ethics departments.
When will data be available (start and end dates)?
Available 18-24 months after publication of the results
End 5 years after publication.
Available to whom?
Researchers who provide a methodologically sound proposal that has been approved by the study steering committee
Available for what types of analyses?
Examples include: meta-analyses. Investigators will consider other applications.
How or where can data be obtained?
Through a signed data sharing agreement and by emailing the principal investigator Dr Anstey.
What supporting documents are/will be available?
No other documents available
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