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Trial registered on ANZCTR


Registration number
ACTRN12610000522011
Ethics application status
Approved
Date submitted
23/06/2010
Date registered
24/06/2010
Date last updated
8/06/2021
Date data sharing statement initially provided
8/06/2021
Date results information initially provided
8/06/2021
Type of registration
Prospectively registered

Titles & IDs
Public title
High flow oxygen therapy in obese hospitalised patients: effects on carbon dioxide levels in the blood.
Scientific title
A randomised, controlled crossover trial of the effect of high concentration oxygen on transcutaneous carbon dioxide tension in obese hospitalised patients.
Secondary ID [1] 252079 0
Nil
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Hypercapnia as a consequence of oxygen therapy in obese individuals. 257622 0
Condition category
Condition code
Diet and Nutrition 257798 257798 0 0
Obesity
Respiratory 257811 257811 0 0
Other respiratory disorders / diseases

Intervention/exposure
Study type
Interventional
Description of intervention(s) / exposure
Oxygen via face mask at 8L/min for 60 minutes, with recorded measurements of heart rate, respiratory rate, oxygen saturations and transcutaneous carbon dioxide (PtCO2) levels at baseline, 10, 20, 30, 40, 50 and 60 minutes. Subjects will also have these parameters continuously monitored during the intervention, with cessation of the intervention immediately should PtCO2 exceed 10mmHg from baseline
Intervention code [1] 256703 0
Treatment: Other
Intervention code [2] 256710 0
Prevention
Comparator / control treatment
Oxygen adjusted to the minimal rate required to keep oxygen saturations of 88 to 92 % for 60 minutes. Measurements will be recorded of heart rate, respiratory rate, oxygen saturations and transcutaneous carbon dioxide (PtCO2) levels at baseline, 10, 20, 30, 40, 50 and 60 minutes. Subjects will also have these parameters continuously monitored during the intervention, with cessation of the intervention immediately should PtCO2 exceed 10mmHg from baseline.
Control group
Dose comparison

Outcomes
Primary outcome [1] 258664 0
Change in PtCO2 from baseline. PtCO2 and oxygen saturation (SpO2) are assessed via a combined SpO2/PtCO2 non-invasive monitor (SENTEC (SenTec AG, Switzerland)).

Timepoint [1] 258664 0
PtCO2 levels will be recorded at baseline and at the following times from onset of the intervention: 10 mins, 20 mins, 30 mins, 40 mins, 50 mins and 60 mins.
Secondary outcome [1] 264641 0
Proportion of subjects who have a change in PtCO2 from baseline of greater than or equal to 4mmHg.
Timepoint [1] 264641 0
This will be assessed from the recorded data taken from each subject at baseline, 10 mins, 20 mins, 30 mins, 40 mins, 50 mins and 60 mins.
Secondary outcome [2] 264642 0
Rate of change of PtCO2.
Timepoint [2] 264642 0
This will be assessed from the recorded data taken from each subject at baseline, 10 mins, 20 mins, 30 mins, 40 mins, 50 mins and 60 mins of intervention.
Secondary outcome [3] 329144 0
Change in Respiratory Rate from baseline. Assessed by investigator count.
Timepoint [3] 329144 0
Taken from each subject at baseline, 10 mins, 20 mins, 30 mins, 40 mins, 50 mins and 60 mins of intervention.
Secondary outcome [4] 329145 0
Change in Heart Rate from baseline. Assessed by SENTEC.
Timepoint [4] 329145 0
Taken from each subject at baseline, 10 mins, 20 mins, 30 mins, 40 mins, 50 mins and 60 mins of intervention.
Secondary outcome [5] 329146 0
Change in Oxygen Saturation from baseline. Assessed by SENTEC.
Timepoint [5] 329146 0
Taken from each subject at baseline, 10 mins, 20 mins, 30 mins, 40 mins, 50 mins and 60 mins of intervention.

Eligibility
Key inclusion criteria
1. Current internal medicine inpatient in Wellington Hospital; 2. Age >/= 16 years; 3. Body Mass Index (BMI) > 40kg/m2.
Minimum age
16 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
1. Diagnosis of Chronic Obstructive Pulmonary Disease (COPD); 2. Ratio of Forced Expiratory Volume in one second to Forced Vital Capacity (FEV1:FVC) < 0.7 (First 24 participants recruited only); 3. Patients currently receiving treatment with Continuous Positive Airway Pressure (CPAP) ventilation or Non-Invasive Positive Pressure Ventilation (NIPPV); 4. Patients currently requiring >2L/minute of oxygen therapy following titration to the recommended target saturation range of 88-92% (First 24 participants recruited only); 5. Patients with baseline PtCO2 of >65mmHg; 6. Current diagnosis of disease causing restriction to chest wall expansion, other than obesity i.e. neuromuscular disease or chest wall dysfunction; 7. Administration of respiratory suppressant medications, including opiate analgesia and benzodiazepines within 24 hours (First 24 participants recruited only); 8. Patients with unstable angina or recent myocardial infarction.

Study design
Purpose of the study
Prevention
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
The study will be explained by the study investigator(s) verbally and with written information in the form of a participant information sheet provided in advance. Informed consent in written form will be obtained and the participant will be screened for eligibility. A randomisation sequence, determining the order in which the subjects receive the interventions, will be generated by a statistician. A third party, not directly involved with the study, will then file these sequences into 24 (24 = target subject number) sealed uniform opaque envelopes. Study investigators will have had no involvement with the generation of these envelopes. If eligible, subjects will be randomised to the order in which they receive their interventions as determined by one of the envelopes.

Note the above will occur for both the 24 participants recruited under tight exclusion criteria and the 24 participants recruited under fewer exclusion criteria.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
The random selection from a remotely generated set of uniform envelopes, each allocating the order in which to apply the interventions.
Masking / blinding
Who is / are masked / blinded?



Intervention assignment
Other design features
Phase
Not Applicable
Type of endpoint/s
Statistical methods / analysis

Recruitment
Recruitment status
Completed
Date of first participant enrolment
Anticipated
15/11/2011
Actual
15/11/2011
Date of last participant enrolment
Anticipated
Actual
7/09/2015
Date of last data collection
Anticipated
Actual
7/09/2015
Sample size
Target
48
Accrual to date
Final
48
Recruitment outside Australia
Country [1] 2708 0
New Zealand
State/province [1] 2708 0

Funding & Sponsors
Funding source category [1] 257169 0
Charities/Societies/Foundations
Name [1] 257169 0
Medical Research Institute of New Zealand (MRINZ)
Country [1] 257169 0
New Zealand
Primary sponsor type
Charities/Societies/Foundations
Name
Medical Research Institute of New Zealand
Address
Level G
Clinical Services Block
Wellington Hospital
Riddiford Street
Newtown
Wellington 6021


POSTAL: Private Bag 7902, Wellington 6242
Country
New Zealand
Secondary sponsor category [1] 256426 0
None
Name [1] 256426 0
Address [1] 256426 0
Country [1] 256426 0
Other collaborator category [1] 251334 0
Hospital
Name [1] 251334 0
Capital & Coast District Health Board
Address [1] 251334 0
Wellington Hospital
Riddiford Street
Wellington 6021
Country [1] 251334 0
New Zealand

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 259211 0
Central Regional Ethics Committee
Ethics committee address [1] 259211 0
Ministry of Health
Level 2, 1-3 The Terrace
PO Box 5013
Wellington 6011
Ethics committee country [1] 259211 0
New Zealand
Date submitted for ethics approval [1] 259211 0
Approval date [1] 259211 0
19/05/2010
Ethics approval number [1] 259211 0
CEN/10/03/08

Summary
Brief summary
Overweight individuals are at increased risk of a number of complications including obesity hypoventilation syndrome (OHS). It has been shown that high concentration oxygen therapy increases arterial carbon dioxide tension (PaCO2) levels in patients with OHS. We now seek to determine whether a similar response occurs in obese subjects, regardless of whether or not they have OHS. This would be relevant to clinical practice as obese patients presenting to hospital with an acute medical condition may routinely given high flow oxygen therapy. This study aims to investigate whether the administration of high concentration oxygen leads to carbon dioxide retention in a group of obese hospital inpatients.
Trial website
Trial related presentations / publications
Public notes
One of the transcutaneous TOSCA probes used in data collection for the first set of 24 participants was found to require re-surfacing when subsequently reviewed by the manufacturer. Another of the probes used during that time was advised not to be used further following ongoing difficulty with calibration. It is uncertain the extent to which the condition of these probes may have affected the accuracy of the data collected. The study was repeated, and only the data from the second set of 24 participants is to be analysed and submitted for peer reviewed publication.

Contacts
Principal investigator
Name 31322 0
Dr Kyle Perrin
Address 31322 0
C/O J Pilcher
Medical Resaerch Institute of New Zealand
Private Bag 7902
Wellington 6242
New Zealand
Country 31322 0
New Zealand
Phone 31322 0
+64 4 8050241
Fax 31322 0
Email 31322 0
[email protected]
Contact person for public queries
Name 14569 0
Dr Janine Pilcher
Address 14569 0
C/O J Pilcher
Medical Research Institute of New Zealand
Private Bag 7902
Wellington 6242
New Zealand
Country 14569 0
New Zealand
Phone 14569 0
+64 4 8050241
Fax 14569 0
Email 14569 0
[email protected]
Contact person for scientific queries
Name 5497 0
Janine Pilcher
Address 5497 0
C/O J Pilcher
Medical Research Institute of New Zealnd
Private Bag 7902
Wellington 6242
New Zealand
Country 5497 0
New Zealand
Phone 5497 0
+64 4 8050241
Fax 5497 0
Email 5497 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No/undecided IPD sharing reason/comment


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
TypeIs Peer Reviewed?DOICitations or Other DetailsAttachment
Study results articleYes Pilcher J, Richards M, Eastlake L, McKinstry SJ, B... [More Details]
ThesisNo https://researcharchive.vuw.ac.nz/xmlui/handle/100... [More Details]

Documents added automatically
SourceTitleYear of PublicationDOI
EmbaseHigh flow or titrated oxygen for obese medical inpatients: A randomised crossover trial.2017https://dx.doi.org/10.5694/mja17.00270
N.B. These documents automatically identified may not have been verified by the study sponsor.