Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12614000924651
Ethics application status
Approved
Date submitted
19/08/2014
Date registered
28/08/2014
Date last updated
28/08/2014
Type of registration
Retrospectively registered

Titles & IDs
Public title
High speed photography to determine the presence or absence of airborne droplets in the exhaled air of subjects wearing high flow nasal cannulae (OptiflowTM) with calculations of trajectory and drying time
Scientific title
Airborne droplet generation in the exhaled air of healthy subjects wearing high flow nasal cannulae
Secondary ID [1] 285189 0
Nil
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Infection control for respiratory viruses 292789 0
Condition category
Condition code
Respiratory 293089 293089 0 0
Other respiratory disorders / diseases
Infection 293143 293143 0 0
Studies of infection and infectious agents

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
Humidified high flow nasal cannulae are used in many clinical settings including the home and acute care hospital settings such as high dependency units and intensive care units. These cannulae are used to deliver a range of flows up to 60L/min of heated and humidified gases to support patients with compromised respiratory function. It is thought that airborne droplets in the exhaled gases may lead to the spread of respiratory viruses.
Defining the potential dispersal of viruses via aerosol is essential for the development of prevention measures therefore to determine if the cannula generates more exhaled droplets than compared to natural breathing is vital

High speed photography shall be used to determine the presence or absence of airborne droplets when high flow nasal cannulae are used in six participants at 30 and 60L/min respectively. Duration 5-10 mins.
Intervention code [1] 290056 0
Not applicable
Comparator / control treatment
NA
Control group
Uncontrolled

Outcomes
Primary outcome [1] 292952 0
Droplet trajectory
A region of approximately 4x4cm immediately below the participants’ nostrils shall be imaged. A Redlake Motion Pro X3 camera shall be used at 1040 frames per second, shutter speed of 40 micro seconds and resolution of 256 x 1024 pixels. The region shall be backlit with four high output LEDs and a diffusing screen of sandblasted PMMA. This will cast a silhouette of the nose and of any droplets onto the camera. A chin and forehead rest of the type used by ophthalmologists ensured that the participant could consistently place their nose in the field of view.
The camera will focuss on first the right, then the left nostril in subsequent imaged sets. The camera shall run throughout the test, and a clip of between 100 and 700 frames showing the greatest number of droplets was obtained from each experimental test.
Timepoint [1] 292952 0
5-10min
Secondary outcome [1] 310000 0
Number and size of exhaled droplets
Timepoint [1] 310000 0
The images of the exhaled droplets shall be processed using ImageJ, a Java image processing and analysis program.
The digital videos of the droplets shall be converted to grayscale using the Image/Type/8-bit function. The images shall then be thresholded using the Image/Adjust/Threshold menu with the typical threshold value of 25-50 grey levels.
Droplet number, size and position shall be analyzed using the Analyze/Analyze Particles panel.
Over aprox 30mins

Eligibility
Key inclusion criteria
Healthy volunteers who have consented to participate
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
Unable or willing to give consent

Study design
Purpose
Natural history
Duration
Cross-sectional
Selection
Convenience sample
Timing
Prospective
Statistical methods / analysis
Statistical tests were two-sided at 5% significance level. Due to the exploratory nature of this study, no adjustment will be made on multiple comparisons. This was a convenience sample no power calculation was done to determine a sample size.

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
4/01/2010
Actual
8/01/2010
Date of last participant enrolment
Anticipated
Actual
30/11/2013
Date of last data collection
Anticipated
Actual
Sample size
Target
6
Accrual to date
Final
Recruitment outside Australia
Country [1] 6300 0
New Zealand
State/province [1] 6300 0

Funding & Sponsors
Funding source category [1] 289801 0
Commercial sector/Industry
Name [1] 289801 0
Fisher & Paykel Healthcare
Country [1] 289801 0
New Zealand
Primary sponsor type
University
Name
University of Canterbury
Address
School of Engineering
University of Canterbury
20 Kirkwood Ave, Upper Riccarton, Christchurch 8041
Country
New Zealand
Secondary sponsor category [1] 288491 0
None
Name [1] 288491 0
Address [1] 288491 0
Country [1] 288491 0

Ethics approval
Ethics application status
Approved

Summary
Brief summary
Humidified High Flow Nasal cannulae (Optiflow Trademark Fisher and Paykel Healthcare, Auckland, New Zealand) are in use in many clinical settings including the home and the hospital. These cannulae are used to deliver a range of flows of heated and humidified gases to support patients with a variety of conditions including those with a compromised respiratory status. It is thought that whilst patients are on this therapy that their exhaled gases laden with viral airborne droplets (aerosols) may lead to an increased infection control risk. Determining both the potential dispersal of viruses via aerosol and whether the use of a cannula generates more exhaled droplets compared to normal resting breathing and forced nasal exhalation (snorting), is vital as this shall help inform any control measures.
The hypothesis under consideration was that Optiflow use does not pose an increased risk of Hospital Acquired Infections (HAI’s) from an infection prevention and control perspective.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 50782 0
Prof Mark Jermy
Address 50782 0
School of Engineering
University of Canterbury
20 Kirkwood Ave, Upper Riccarton, Christchurch 8041
Country 50782 0
New Zealand
Phone 50782 0
+64 2102916549
Fax 50782 0
Email 50782 0
[email protected]
Contact person for public queries
Name 50783 0
Ms Jane Clarke
Address 50783 0
Fisher & Paykel Healthcare
15 Maurice Paykel Place, East Tamaki, Auckland 2013
PO Box 14 348 Panmure, Auckland 1741 New Zealand
Country 50783 0
New Zealand
Phone 50783 0
+649 5740100
Fax 50783 0
Email 50783 0
[email protected]
Contact person for scientific queries
Name 50784 0
Prof Mark Jermy
Address 50784 0
School of Engineering
University of Canterbury
20 Kirkwood Ave, Upper Riccarton, Christchurch 8041
Country 50784 0
New Zealand
Phone 50784 0
+64 2102916549
Fax 50784 0
Email 50784 0
[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
SourceTitleYear of PublicationDOI
EmbaseAssessment of dispersion of airborne particles of oral/nasal fluid by high flow nasal cannula therapy.2021https://dx.doi.org/10.1371/journal.pone.0246123
N.B. These documents automatically identified may not have been verified by the study sponsor.