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Trial registered on ANZCTR


Registration number
ACTRN12618000674235
Ethics application status
Approved
Date submitted
19/04/2018
Date registered
24/04/2018
Date last updated
18/09/2019
Date data sharing statement initially provided
18/09/2019
Type of registration
Prospectively registered

Titles & IDs
Public title
Airway collapsibility as an indicator of perioperative adverse event risk and obstructive sleep apnoea
Scientific title
Airway collapsibility as an indicator of perioperative adverse event risk and obstructive sleep apnoea
Secondary ID [1] 294118 0
Nil
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
obstructive sleep apnoea 306755 0
Airway Collapsibility 306756 0
Condition category
Condition code
Respiratory 305843 305843 0 0
Sleep apnoea

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
This project assesses upper airway collapsibility and peri- and post-operative adverse events in patients undergoing surgery not related to the head, neck, airways or chest. Demographic and anthropometric (height, weight, neck circumference, Mallampati) information will be recorded and a STOP-Bang assessment performed prior to surgery in all consenting patients. Following surgery, prior to transfer to the recovery room, assessment of airway collapsibility will be performed using the Pclose technique. In addition, all adverse events including respiratory adverse events (respiratory depression (rate & depth), desaturation events, requirement for re-intubation or other medical intervention including unplanned initiation of positive airway pressure therapy) will be documented as well as length of stay in hospital and planned and unplanned intensive care unit or high dependency unit admissions. Within 3 weeks of surgery, sleep apnoea severity will be ascertained in a subgroup of consenting participants using a reliable home monitoring device (ApneaLink) for one night.
Intervention code [1] 300423 0
Early Detection / Screening
Comparator / control treatment
No Control Group
Control group
Uncontrolled

Outcomes
Primary outcome [1] 304896 0
Airway collapsibility as assessed by the P Close technique.
Following removal of the laryngeal mask airway, a single use anaesthetic mask with good seal to the patient’s face will be fitted. A flow (pneumotachograph) and pressure sensor (Pmask) and balloon valve capable of completely occluding airflow through the mask will also be connected. Following a period of stable breathing (minimum 5 breaths), complete occlusion will be applied at end expiration resulting in obstructive inspiratory airflow and a progressive increase in inspiratory effort with successive efforts. Each increased effort produces a more negative Pmask until Pclose is reached and Pmask plateaus. The occlusion will be held for a maximum of 5-6 breaths and the results are highly reproducible. Two occlusions will be performed and the mean Pclose calculated. If the two measures differ by more than 10% then a third occlusion will be performed and the closest two measures will be averaged. All assessments will be performed with the patient in the supine position and head neutral.
Timepoint [1] 304896 0
In theatre
Primary outcome [2] 304897 0
Planned and unplanned intensive care unit or high dependency unit admissions. This is a composite measure and will be obtained from their medical records.
Timepoint [2] 304897 0
within the 24h post-surgery
Primary outcome [3] 305542 0
Mean 24hr oxygen saturation (Nonin WristOx)
Timepoint [3] 305542 0
within the 24hr post-surgery
Secondary outcome [1] 343556 0
Severity of obstructive sleep apnoea (AHI) as measured by ApneaLink (Resmed)
Timepoint [1] 343556 0
One night of at home monitoring to occur within 3 weeks of surgery
Secondary outcome [2] 345999 0
Respiratory depression (rate & depth). This will be assessed visually by the medical staff during their routine observations during the 24h period post-surgery.
Timepoint [2] 345999 0
within the 24h post-surgery
Secondary outcome [3] 346001 0
Requirement for re-intubation or other medical intervention including unplanned initiation of positive airway pressure therapy. This information will be obtained from their medical records.
Timepoint [3] 346001 0
within the 24h post-surgery
Secondary outcome [4] 346002 0
length of stay in hospital
Timepoint [4] 346002 0
within the 24h post-surgery

Eligibility
Key inclusion criteria
Patients undergoing surgery not related to head, neck, airways or chest and able to give consent.
Minimum age
18 Years
Maximum age
69 Years
Gender
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Patients less than 18 years old or 70 years and over
Patients undergoing surgery related to the head, neck, airways or chest
Patients who require intubation
Patients with unstable cardiovascular disease
Those unable to speak English
Pregnant or lactating females

Study design
Purpose
Screening
Duration
Cross-sectional
Selection
Defined population
Timing
Prospective
Statistical methods / analysis
To identify a 3±3 cmH2O difference in Pclose between those patients who experience and an adverse event or unplanned transfer (with a at 0.05 and ß at 0.8), assuming a rate of unplanned transfer to ICU or HDU of 5% (based on data from Kaw et al.) 179 patients will need to be studied (170 in non-transfer group, 9 in transfer group). To establish a correlation of 0.4 between OSA severity determined from ApneaLink and Pclose (with a at 0.05 and ß at 0.8) we will need to study of subgroup of 37 people with ApneaLink. To allow for dropout and study failures 200 participants will be recruited for Pclose assessment and 40 for ApneaLink studies (every third consenting participant will be invited to complete the home sleep assessment).
At the completion of data collection, independent samples t-test (where data is normally distributed) and Wilcoxon signed ranks test (where data is not normally distributed) will be used to identify differences in Pclose between patients who do and do not experience an adverse event. Linear regression will be used to examine the relationship between Pclose and OSA severity as determined by ApneaLink.

Recruitment
Recruitment status
Recruiting
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)
WA
Recruitment hospital [1] 10092 0
Sir Charles Gairdner Hospital - Nedlands
Recruitment postcode(s) [1] 21628 0
6009 - Nedlands

Funding & Sponsors
Funding source category [1] 298755 0
Hospital
Name [1] 298755 0
Sir Charles Gairdner Hospital
Address [1] 298755 0
Hospital Avenue
Nedlands, WA 6009
Country [1] 298755 0
Australia
Primary sponsor type
Other Collaborative groups
Name
Australian and New Zealand College of Anaesthetists
Address
630 St Kilda Rd
Melbourne, VIC, 3004
Country
Australia
Secondary sponsor category [1] 298269 0
None
Name [1] 298269 0
Address [1] 298269 0
Country [1] 298269 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 299694 0
Sir Charles Gairdner and Osborne Park Health Care Group Human Research Ethics Commitee
Ethics committee address [1] 299694 0
2nd Floor A Block
Hospital Avenue
Nedlands, WA, 6009
Ethics committee country [1] 299694 0
Australia
Date submitted for ethics approval [1] 299694 0
21/11/2017
Approval date [1] 299694 0
02/03/2018
Ethics approval number [1] 299694 0
RGS0000000279

Summary
Brief summary
This project is an observational study assessing upper airway collapsibility and peri- and post-operative adverse events in patients undergoing surgery not related to the head, neck, airways or chest. Demographic and anthropometric (height, weight, neck circumference, Mallampati) information will be recorded and a STOP-Bang assessment performed prior to surgery in all consenting patients. Following surgery, prior to transfer to the recovery room, assessment of airway collapsibility will be performed using the Pclose technique. In addition, all adverse events including respiratory adverse events (respiratory depression (rate & depth), desaturation events, requirement for re-intubation or other medical intervention including unplanned initiation of positive airway pressure therapy) will be documented as well as length of stay in hospital and planned and unplanned intensive care unit or high dependency unit admissions. Within 3 weeks of surgery, sleep apnoea severity will be ascertained in a subgroup of consenting participants with a reliable home monitoring device (ApneaLink).

The expected outcome of this research is to demonstrate that Pclose is a suitable method for quickly identifying the presence of abnormal airway collapsibility in surgical patients and that airway collapsibility, as measured by Pclose, is greater in those people who experience post-operative adverse events. This will then potentially enable high-risk patients to be stratified to the appropriate level of care and improve post-operative patient safety. It is hypothesised that more adverse respiratory events will occur in those patients with the greatest airway collapsibility. In addition, a measure of airway collapsibility in the early post-operative period may provide a useful tool for identifying patients at high risk of OSA beyond the perioperative period. In those patients, it is hypothesised that airway collapsibility will be greatest in those with the most severe OSA and lowest in those patients without OSA.
Trial website
Trial related presentations / publications
Public notes
Attachments [1] 2516 2516 0 0

Contacts
Principal investigator
Name 81314 0
Dr Jennifer Walsh
Address 81314 0
Department of Pulmonary Physiology and Sleep Medicine
Sir Charles Gairdner Hospital
Internal Mailbox 201
Hospital Avenue
Nedlands WA 6009
Country 81314 0
Australia
Phone 81314 0
+61 8 6457 1070
Fax 81314 0
Email 81314 0
jennifer.walsh@health.wa.gov.au
Contact person for public queries
Name 81315 0
Dr Jennifer Walsh
Address 81315 0
Department of Pulmonary Physiology and Sleep Medicine
Sir Charles Gairdner Hospital
Internal Mailbox 201
Hospital Avenue
Nedlands WA 6009
Country 81315 0
Australia
Phone 81315 0
+61 8 6457 1070
Fax 81315 0
Email 81315 0
jennifer.walsh@health.wa.gov.au
Contact person for scientific queries
Name 81316 0
Dr Jennifer Walsh
Address 81316 0
Department of Pulmonary Physiology and Sleep Medicine
Sir Charles Gairdner Hospital
Internal Mailbox 201
Hospital Avenue
Nedlands WA 6009
Country 81316 0
Australia
Phone 81316 0
+61 8 6457 1070
Fax 81316 0
Email 81316 0
jennifer.walsh@health.wa.gov.au

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
Yes
What data in particular will be shared?
after de-identification individual participant data underlying published results only
When will data be available (start and end dates)?
Beginning 3 months and ending 5 years following main results publication
Available to whom?
only researchers who provide a methodologically sound proposal
Available for what types of analyses?
only to achieve the aims in the approved proposal
How or where can data be obtained?
access subject to approvals by Principal Investigator
What supporting documents are/will be available?
No other documents available
Summary results
No Results