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Trial registered on ANZCTR


Registration number
ACTRN12620000262909
Ethics application status
Approved
Date submitted
10/02/2020
Date registered
27/02/2020
Date last updated
27/02/2020
Date data sharing statement initially provided
27/02/2020
Type of registration
Prospectively registered

Titles & IDs
Public title
Stomach distension with high flow nasal oxygen therapy. A volunteer study

Scientific title
Gastric insufflation with high flow nasal oxygen therapy. A volunteer study

Secondary ID [1] 300497 0
Nil Known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Gastric insufflation 316179 0
High flow nasal oxygen therapy 316180 0
Gastrointestinal system 316307 0
Gastric distension 316308 0
Condition category
Condition code
Oral and Gastrointestinal 314472 314472 0 0
Other diseases of the mouth, teeth, oesophagus, digestive system including liver and colon

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
When the participants are ready, a baseline ultrasound estimate of the stomach volume estimate is done. Thereafter, oxygen will be delivered through a high-flow nasal cannula. This will be accomplished using the Optiflow THRIVE device (Opti-Flow, Auckland, New Zealand). Flow rate through the cannula will be commenced at 30 L/min and fractional inspired oxygen concentration will be set at 100%. The flow will be gradually increased and maintained at 60-70L/min during the study. The flow rate could be decreased up to 30 L/min if higher flow rate is not tolerated.
A set of ultrasound measurements looking for gastric distension and stomach volume will be made at 10 min intervals till 30 minutes of HFNC delivery. Measurements will be obtained between peristaltic contractions when the stomach is resting. A set of three measurements will be made for each outcome variable and the mean value would be recorded. The HFNC will be ceased at 30 minutes and the participants are allowed to rest for another 30 minutes. During this time, they are not allowed to eat or drink. Another set of scans and measurements of stomach volume and distension will be obtained 30 minutes after ceasing HFNC. Peripheral oxygen saturation (SPO2) will be monitored throughout the study.

The intervention will be carried out by anaesthesiologists and it will be performed in the post anaesthesia care unit where appropriate facilities are available to conduct the study.
Intervention code [1] 316805 0
Treatment: Other
Comparator / control treatment
No control group
Control group
Uncontrolled

Outcomes
Primary outcome [1] 322802 0
Incidence of gastric distension, defined by distended antrum with air content that blurs the posterior wall (described as comets tail artefact). Recorded as Yes/No
Timepoint [1] 322802 0
10 minutes
Primary outcome [2] 322803 0
Incidence of gastric distension, defined by distended antrum with air content that blurs the posterior wall (described as comets tail artefact). Recorded as Yes/No
Timepoint [2] 322803 0
20 minutes
Primary outcome [3] 322804 0
Incidence of gastric distension, defined by distended antrum with air content that blurs the posterior wall (described as comets tail artefact). Recorded as Yes/No
Timepoint [3] 322804 0
30 minutes
Secondary outcome [1] 379838 0
Change in the gastric antral area compared to baseline using ultrasound estimates
Timepoint [1] 379838 0
10 minutes, 20 minutes, 30 minutes and 60 minutes
Secondary outcome [2] 379839 0
Dryness of mouth: Yes/NO
Timepoint [2] 379839 0
60 minutes
Secondary outcome [3] 379840 0
d) Volunteer comfort: 5-point Likert scale (completed 5 min after the study)
Very comfortable (5), mildly uncomfortable (4), moderately uncomfortable (3), very uncomfortable (2), intolerable (1)
Timepoint [3] 379840 0
60 minutes
Secondary outcome [4] 380194 0
Dryness of Nose: Yes/NO
Timepoint [4] 380194 0
60 minutes
Secondary outcome [5] 380195 0
Sensation of
Nausea: Yes/No
Timepoint [5] 380195 0
60 minutes
Secondary outcome [6] 380196 0
Vomiting: Yes/NO
Timepoint [6] 380196 0
60 minutes
Secondary outcome [7] 380197 0
Bloating of the stomach: Yes/No
Timepoint [7] 380197 0
60 minutes

Eligibility
Key inclusion criteria
Healthy non-pregnant volunteers 18-70 yrs, both males and females
No significant organ impairment
No language barrier
Fasted for 6 hours for solids and liquids. Sips of water allowed till 2 hours of the study enrolment
Minimum age
18 Years
Maximum age
70 Years
Gender
Both males and females
Can healthy volunteers participate?
Yes
Key exclusion criteria
History of severe gastro oesophageal reflux disease, hiatus hernia, previous gastro-oesophageal or duodenal surgery
Those who are on medications affecting gastric motility
History of nasal blockage or congestion
Participants unable to consent
Diabetes mellitus
Morbid obesity >40 BMI

Study design
Purpose of the study
Treatment
Allocation to intervention
Non-randomised trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?



Intervention assignment
Single group
Other design features
Voluntary study on a convenience sample of volunteers
Phase
Not Applicable
Type of endpoint(s)
Safety
Statistical methods / analysis

Recruitment
Recruitment status
Not yet 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)
SA
Recruitment hospital [1] 15829 0
The Queen Elizabeth Hospital - Woodville
Recruitment postcode(s) [1] 29272 0
5011 - Woodville

Funding & Sponsors
Funding source category [1] 304915 0
Hospital
Name [1] 304915 0
Department of Anaesthesia, The Queen Elizabeth Hospital, Woodvill, SA
Address [1] 304915 0
The Queen Elizabeth Hospital
28 Woodville Road
Woodville
SA 5011
Country [1] 304915 0
Australia
Primary sponsor type
Hospital
Name
The Queen Elizabeth Hospital
Address
28 Woodpile Road, Woodville, SA 5011
Country
Australia
Secondary sponsor category [1] 305260 0
None
Name [1] 305260 0
Address [1] 305260 0
Country [1] 305260 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 305322 0
Central Adelaide Local Health Network Human Research Ethics Committee
Ethics committee address [1] 305322 0
Royal Adelaide Hospital
Clinical Trial Centre
Level 3, Wayfiner 3D460.02
Port Road
Adelaide SA 5000
Ethics committee country [1] 305322 0
Australia
Date submitted for ethics approval [1] 305322 0
12/10/2019
Approval date [1] 305322 0
29/12/2019
Ethics approval number [1] 305322 0
Q20190410

Summary
Brief summary

High flow nasal cannula (HFNC) has been shown to provide better oxygenation compared to the venturi face mask and low flow nasal cannula during intravenous sedation for both bronchoscopy and dental procedures . Though there are no major effects reported with this device, gastric distension is a theoretical possibility. Continuous high flow together with the ability to create low levels of positive airway pressure can potentiate gastric distension. When gastric distension occurs, it causes an increase in the secretion of gastric acid through vagal response. Hence, there is a potential for increased gastric volume and secretions, along with an elevated intraluminal pressure. This may increase the risk of pulmonary aspiration of gastric contents. Data is lacking as to quantify this issue in clinical practice. The aim of this study is to assess gastric insufflation and volume in healthy volunteers after application of HFNC.
We hypothesise that the application of high flow nasal oxygen will not result in gastric distension.
Measurements will be made of the incidence of gastric insufflation before and after the application of HFNC.
When the participants are ready, a baseline ultrasound estimate of the stomach volume estimate is done. Thereafter, oxygen will be delivered through a high-flow nasal cannula. This will be accomplished using the Optiflow THRIVE device (Opti-Flow, Auckland, New Zealand). Flow rate through the cannula will be commenced at 30 L/min and fractional inspired oxygen concentration will be set at 100%. The flow will be gradually increased and maintained at 60-70L/min during the study. The flow rate could be decreased up to 30 L/min if higher flow rate is not tolerated.
A set of ultrasound measurements looking for gastric distension and antral area will be made at 10 minutes intervals till 30 minutes of HFNC delivery. Measurements will be obtained between peristaltic contractions when the stomach is resting. A set of three measurements will be made for each outcome variable and the mean value would be recorded. The HFNC will be ceased at 30 minutes and the participants are allowed to rest for another 30 minutes. During this time, they are not allowed to eat or drink. Another set of scans and measurements will be obtained 30 minutes after ceasing HFNC.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 99994 0
Dr Venkatesan Thiruvenkatarajan
Address 99994 0
Staff Specialist
Department of Anaesthesia, The Queen Elizabeth Hospital
28 woodville Road,
Woodville South 5011, Adelaide, South Australia
Country 99994 0
Australia
Phone 99994 0
+61 08 82226640
Fax 99994 0
Email 99994 0
Venkatesan.Thiruvenkatarajan@sa.gov.au
Contact person for public queries
Name 99995 0
Dr Venkatesan Thiruvenkatarajan
Address 99995 0
Staff Specialist
Department of Anaesthesia, The Queen Elizabeth Hospital
28 woodville Road,
Woodville South 5011, Adelaide, South Australia
Country 99995 0
Australia
Phone 99995 0
+61 08 82226640
Fax 99995 0
+61 08 82226640
Email 99995 0
Venkatesan.Thiruvenkatarajan@sa.gov.au
Contact person for scientific queries
Name 99996 0
Dr Venkatesan Thiruvenkatarajan
Address 99996 0
Staff Specialist
Department of Anaesthesia, The Queen Elizabeth Hospital
28 woodville Road,
Woodville South 5011, Adelaide, South Australia
Country 99996 0
Australia
Phone 99996 0
+61 08 82226640
Fax 99996 0
Email 99996 0
Venkatesan.Thiruvenkatarajan@sa.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?
Non identifiable study results
When will data be available (start and end dates)?
Beginning 3 months and following 5 years after publication
Available to whom?
Anyone who wishes to access it
Available for what types of analyses?
For approved study proposals and for general information to the public
How or where can data be obtained?
By contacting the principal investigator through Phone
Phone number: 0061 08 8222 6640
Department of Anaesthesia, The Queen Elizabeth Hospital, Woodville, SA 5011
What supporting documents are/will be available?
No other documents available
Summary results
No Results