Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12619000613101
Ethics application status
Approved
Date submitted
15/04/2019
Date registered
24/04/2019
Date last updated
3/10/2023
Date data sharing statement initially provided
24/04/2019
Type of registration
Prospectively registered

Titles & IDs
Public title
Investigation of improved nasal high flow to enhance carbon dioxide (CO2) clearance and maintain oxygen saturation during shared airway surgery
Scientific title
Investigation of improved nasal high flow to enhance CO2 clearance and maintain oxygen saturation during shared airway surgery
Secondary ID [1] 297812 0
None
Universal Trial Number (UTN)
U1111-1230-7056
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Destauration/oxygenation during anaesthesia 312263 0
airway management 312418 0
Condition category
Condition code
Anaesthesiology 310810 310810 0 0
Anaesthetics

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Nasal High flow with non-constant flow, 30-100l/min.
This therapy will be delivered from a prototype flow controller coupled with a humidifier, water chamber and breathing circuit. Relative humidity will be approximately 100% at 37degC.

The therapy will be administered under the direction of an anaesthetist through a non sealing nasal interface to patients presenting for shared airway surgery in an operating room. The therapy will be delivered continuously for a minimum of 25 minutes and a maximum of 40 minutes from induction of anaesthesia.
We will record any times where the intervention is halted at the request of the surgeon or anaesthetist

Flow sub-study:
A sub study, already approved under the same ethics approval, will be conducted to investigate flows coming out of the suspension laryngoscope. This sub study will be conducted in ten patients, recruited sequentially from patients participating in the main study. The inclusion and exclusion criteria are identical to the main study. A measurement of the flow rate coming from the suspension laryngoscope will be made at the conclusion of the patient's surgery (i.e. immediately after measurements in the main study). The study involves placing a flowmeter into the suspension laryngoscope via an adaptor. Readings from the flow meter are captured by a computer and logged for 60s. The pressure in the laryngoscope, which is a variable in the main study, will continue to be recorded during this sub study. Recruitment will be from the first suitable surgical list in September 2023 until ten patients have been recruited, expected to take 3-6 months, i.e. recruitment is expected to be from September 2023 until March 2024. Results from this sub study will be analysed and published as soon as they are available, regardless of whether the main study has concluded.
Intervention code [1] 314116 0
Treatment: Devices
Comparator / control treatment
Nasal high flow with constant flow (70l/min)
This therapy will be delivered from a prototype flow controller coupled with a humidifier, water chamber and breathing circuit. Relative humidity will be approximately 100% at 37degC.
The therapy will be administered under the direction of an anaesthetist through a non sealing nasal interface to patients presenting for shared airway surgery in an operating room. The therapy will be delivered continuously for a minimum of 25 minutes and a maximum of 40 minutes from induction of anaesthesia, where the end of the study will be determined by the surgical procedure length or at the request of the anasethetist.
We will record any times where the control is halted at the request of the surgeon or anaesthetist (e.g. when other airway management tools are employed)
Control group
Active

Outcomes
Primary outcome [1] 319653 0
Change in arterial CO2 from baseline as measured by arterial blood gas sample during shared airway surgery over the period 5-25 minutes.
An arterial blood gas sample will be taken from an arterial line and a standard blood gas analyser will be used to determine the PaCO2.
Timepoint [1] 319653 0
Over the period from 5 minutes post induction to 25 minutes post induction
Secondary outcome [1] 369029 0
Proportion of patients with PaCO2>8kPa (60mmHg)
An arterial blood gas sample will be taken from an arterial line and a standard blood gas analyser will be used to determine the PaCO2.
Timepoint [1] 369029 0
t = 0,5,10,15,20, 25, 30, 35, 40 minutes (where t=0 is the time of induction)
Secondary outcome [2] 369031 0
time to reach PaCO2>8kPa.
An arterial blood gas sample will be taken from an arterial line and a standard blood gas analyser will be used to determine the PaCO2.
Timepoint [2] 369031 0
time to reach PaCO2>8kPa as assessed from arterial blood gas samples taken every 2.5 minutes.
An arterial blood gas sample will be taken from an arterial line and a standard blood gas analyser will be used to determine the PaCO2.
Secondary outcome [3] 369032 0
maximum PaCO2
An arterial blood gas sample will be taken from an arterial line and a standard blood gas analyser will be used to determine the PaCO2.
Timepoint [3] 369032 0
Over the period from 5 minutes post induction to 25 minutes post induction every 2.5 minutes
Secondary outcome [4] 369033 0
maximum change in PaCO2 from baseline. An arterial blood gas sample will be taken from an arterial line and a standard blood gas analyser will be used to determine the PaCO2.
Timepoint [4] 369033 0
Over the period from 5 minutes post induction to 25 minutes post induction every 2.5 minutes
Secondary outcome [5] 369034 0
minimum pH
An arterial blood gas sample will be taken from an arterial line and a standard blood gas analyser will be used to determine the pH.
Timepoint [5] 369034 0
Over the period from 5 minutes post induction to 25 minutes post induction every 2.5 minutes
Secondary outcome [6] 369035 0
maximum change in pH from baseline
An arterial blood gas sample will be taken from an arterial line and a standard blood gas analyser will be used to determine the pH.
Timepoint [6] 369035 0
Over the period from 5 minutes post induction to 25 minutes post induction every 2.5 minutes
Secondary outcome [7] 369036 0
proportion of patients with pH<7.2
An arterial blood gas sample will be taken from an arterial line and a standard blood gas analyser will be used to determine the pH.
Timepoint [7] 369036 0
t = 0,5,10,15,20, 25, 30, 35, 40 minutes
Secondary outcome [8] 369037 0
oxygen saturation (Time SpO2<90%) as measured continuously with a standard pulse oximeter
Timepoint [8] 369037 0
Over the period from 5 minutes post induction to 25 minutes post induction
Secondary outcome [9] 369038 0
minimum Oxygen saturation as measured continuously with a standard pulse oximeter
Timepoint [9] 369038 0
Over the period from 5 minutes post induction to 25 minutes post induction
Secondary outcome [10] 369039 0
mean Oxygen saturation as measured continuously with a standard pulse oximeter
Timepoint [10] 369039 0
Over the period from 5 minutes post induction to 25 minutes post induction
Secondary outcome [11] 369040 0
mean PaO2
An arterial blood gas sample will be taken from an arterial line and a standard blood gas analyser will be used to determine the PaO2.
Timepoint [11] 369040 0
Over the period from 5 minutes post induction to 25 minutes post induction every 2.5 minutes
Secondary outcome [12] 369041 0
minimum PaO2
An arterial blood gas sample will be taken from an arterial line and a standard blood gas analyser will be used to determine the PaO2.
Timepoint [12] 369041 0
Over the period from 5 minutes post induction to 25 minutes post induction every 2.5 minutes
Secondary outcome [13] 369042 0
post-surgical rating by surgeon of the overall effect on the surgical field on a 100mm visual analogue scale with anchors “no effect” to “incompatible with this surgical application”.
Timepoint [13] 369042 0
end of procedure
Secondary outcome [14] 369043 0
usability from the perspective of the surgeon, especially the stability of the surgical field as measured by the proportion of time that the surgeon asks for the therapy to be switched off
Timepoint [14] 369043 0
end of procedure
Secondary outcome [15] 369044 0
post-surgical free comments by surgeon. The surgeon will be invited to dictate comeents that will be recorded on the case report form.
Timepoint [15] 369044 0
end of procedure
Secondary outcome [16] 369045 0
Pressure as measured with a pressure transducer connected to the port of the suspension laryngascope. This will be used to confirm airway pressure .
Timepoint [16] 369045 0
From placement of laryngascope until 25 minutes after induction. Sampling rate is 100Hz.
Secondary outcome [17] 369046 0
degree of movement of the vocal chords as measured by video imaging
Timepoint [17] 369046 0
To be measured during the procedure when the surgeon determines the measurement will not adversely affect the procedure.
Secondary outcome [18] 369525 0
Exhaled CO2 as measured with a capnograph connected to the port of the suspecnsion laryngascope. This will be used to confirm CO2 clearance.
Timepoint [18] 369525 0
From 25 minutes after induction until the end of the procedure
Secondary outcome [19] 422937 0
Flow out of the suspension laryngoscope.
The gas flow will be measured with a standard flow meter (Sensirion 3200 or similar) connected to the top of the laryngascope with a custom adaptor..
Timepoint [19] 422937 0
At end of surgery. Note: this secondary outcome is a sub study as described in 'Description of intervention'. As such recruitment in this sub study will be from September 2023 until March 2024.

Eligibility
Key inclusion criteria
• 18 years and over and less than 80 years in age
• Capable of informed consent
• Undergoing laryngotrachael surgery under general anaesthetic expected to last at least 15 minutes
Minimum age
18 Years
Maximum age
80 Years
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
• BMI > 35 kg/m2.
• Patients who are deemed unfit for general anaesthesia and/or THRIVE treatment by the anaesthetist.
• Room-air saturation levels <85%
• requiring preoperative oxygen therapy secondary to chronic lung disease
• Pre-existing hypoxemia
• clinically-defined severe concomitant lower airway pulmonary disease
• Known contraindication to Optiflow™ device
• Patients in whom CPAP is contraindicated (e.g. pneumothorax, bullous lung disease, craniofacial trauma, airway, foreign body, unstable haemodynamics)
• history or symptoms of increased intracranial pressure or reduced intracranial compliance ( e.g. headaches, nausea and vomiting, visual changes, mental changes) .
• skull base defects.
• Patients in whom high FiO2 is contraindicated (e.g. patients being treated with Bleomycin)
• Patients undergoing procedures with electrocautery or laser.
• More than 50% (as judged by the anaesthetist) of the nares occluded by the nasal prongs
• Bleeding in nose or oropharynx
• Patients receiving an induction with volatile anaesthetics
• Patients with delicate skin that could be thermally damaged by the transcutaneous monitor

Study design
Purpose of the study
Treatment
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Sealed envelopes
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Simple randomisation using a randomisation table created by computer software (i.e. computerised sequence generation)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s


Intervention assignment
Parallel
Other design features
Phase
Not Applicable
Type of endpoint/s
Efficacy
Statistical methods / analysis
A power calculation was performed by the study statistician using published data on similar studies and an assumed reduction in rate of rise of PaCO2 of 15%.

The primary endpoint and the secondary PaCO2 endpoints will be compared between randomised groups using ANCOVA using the 5 minute PaCO2 level as the covariate.

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
28/10/2020
Actual
28/10/2020
Date of last participant enrolment
Anticipated
31/05/2024
Actual
Date of last data collection
Anticipated
31/05/2024
Actual
Sample size
Target
90
Accrual to date
26
Final
Recruitment outside Australia
Country [1] 21401 0
New Zealand
State/province [1] 21401 0
Auckland

Funding & Sponsors
Funding source category [1] 302337 0
Commercial sector/Industry
Name [1] 302337 0
Fisher & Paykel Healthcare
Country [1] 302337 0
New Zealand
Primary sponsor type
Commercial sector/Industry
Name
Fisher & Paykel Healthcare
Address
15 Maurice Paykel Place
East Tamaki
Auckland 2013
Country
New Zealand
Secondary sponsor category [1] 302216 0
University
Name [1] 302216 0
University of Auckland
Address [1] 302216 0
Faculty of Medical and Health Sciences
The University of Auckland
Private Bag 92019
Auckland 1142
Country [1] 302216 0
New Zealand

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 303012 0
Health and Disability Ethics Commitee - Northern B
Ethics committee address [1] 303012 0
Ministry of Health,
Level 3,Rangitoto Room, Unisys Building,
650 Great South Road, Penrose,
Auckland 1051
Ethics committee country [1] 303012 0
New Zealand
Date submitted for ethics approval [1] 303012 0
07/05/2019
Approval date [1] 303012 0
07/10/2019
Ethics approval number [1] 303012 0
19NTB98

Summary
Brief summary
In shared airway surgery the anaesthetist and surgeon both require access to the airway. Consequently there are some unique challenges in achieving gas exchange (providing oxygen and removing carbon dioxide) in apnoeic patients. Usual practice in general anaesthesia would be to ventilate the patient through a secure airway such as an endotracheal tube or laryngeal mask; however such airway devices make performing surgery in the airway difficult or impossible.
Recently a new technique called Optiflow THRIVE has been reported and its use is rapidly increasing. In this technique, high flows of humidified oxygen at 70l/min are provided to the patient via nasal cannula throughout the procedure. This assists in maintaining oxygen saturation and clears some, but not all, of the carbon dioxide being produced.
The objective of the research described here is to evaluate a modification of the Optiflow THRIVE technique to provide greater clearance of carbon dioxide.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 92158 0
Prof Alan Merry
Address 92158 0
Faculty of Medical and Health Sciences
The University of Auckland
Private Bag 92019
Auckland 1142
Country 92158 0
New Zealand
Phone 92158 0
+64 9 923 5751
Fax 92158 0
Email 92158 0
[email protected]
Contact person for public queries
Name 92159 0
Mr Matthew Payton
Address 92159 0
Fisher&Paykel Healthcare
15 Maurice Paykel Place
Auckland 2013
Country 92159 0
New Zealand
Phone 92159 0
+64 9 5740100
Fax 92159 0
Email 92159 0
[email protected]
Contact person for scientific queries
Name 92160 0
Mr Matthew Payton
Address 92160 0
Fisher&Paykel Healthcare
15 Maurice Paykel Place
Auckland 2013
Country 92160 0
New Zealand
Phone 92160 0
+64 9 574 0100
Fax 92160 0
Email 92160 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
Yes
What data in particular will be shared?
Data relating to the primary outcomes (PaCO2) and selected secondary outcomes (those where the data is in a practical form to share including PaO2, pH, SpO2, transcutaneous O2 and CO2, Surgeon satisfaction score)
When will data be available (start and end dates)?
From the completion of the trial for a minimum of 5 years and a maximum of 10 years.
Available to whom?
1. Investigators with applicable consents and ethical approvals.
2. Regulatory bodies
Available for what types of analyses?
Meta analyses or similar reviews
Data verification
How or where can data be obtained?
Following a written request, if the Principal Investigator and Sponsor both approve, then data would be made available as anonymised electronic records.


What supporting documents are/will be available?

Doc. No.TypeCitationLinkEmailOther DetailsAttachment
12094Study protocol  [email protected]



Results publications and other study-related documents

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No documents have been uploaded by study researchers.

Documents added automatically
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