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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
Apnoeic Oxygenation: A Comparison of Nasal Prongs to Nasopharyngeal Cannula on oxygenation before Intubation
Scientific title
A comparison of fraction of inspired oxygen (FiO2) levels at the pharyngeal inlet due to the application of oxygen via either nasal prongs or nasopharyngeal cannula during apnoea, prior to intubation in patients undergoing elective surgery at Monash Health.
Secondary ID [1] 286237 0
Nil known
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Prevention of Oxygen desaturation during intubation 294289 0
Condition category
Condition code
Anaesthesiology 294610 294610 0 0
Other anaesthesiology

Study type
Description of intervention(s) / exposure
Our study compares the application of oxygen via nasal prongs to nasopharyngeal cannula during the period of apnoea, prior to intubation.
Nasal prongs are a non-invasive means of delivering oxygen. They are comprised of a lightweight tube with two small prongs, each of which enters the nostrils, through which a mixture of oxygen and air is delivered. It is connected to an Oxygen supply.
Nasopharyngeal cannula is a longer, flexible tube which is passed through a single nostril, further into the upper airway until the tip comes to rest at the oropharyngeal inlet. This is also non-invasive and is connected to an oxygen supply so that air and oxygen can be delivered through it.
We will apply the chosen device to our patients before anaesthetic induction and provide normal pre-oxygenation. Oxygen will then run through the devices at 15Litres/minute. This will flow for three minutes, after the patient stops breathing and before intubation is attempted.
Normally, no devices are applied to the patient during this period.
The concentration of oxygen (Fi02) at the pharyngeal inlet is measured just prior to intubation. We will compare these values.
Intervention code [1] 291253 0
Treatment: Devices
Comparator / control treatment
No control group has been included. It has now been excluded from our study.
Control group

Primary outcome [1] 294376 0
Our primary outcome is fraction of inspired Oxygen (Fi02) at the pharyngeal inlet after three minutes of apnoeic oxygenation. We consider a difference of 5% to be clinically significant between the two groups. That is, between the nasal prongs cohort and the nasopharyngeal cohort.
This will be measured from a gas sampling line which will be placed at the pharyngeal inlet after the onset of apnoea. Measurements of Fi02 will be recorded after two minutes and three, but our primary outcome measurement will be that at three minutes.
Timepoint [1] 294376 0
Fi02 levels after three minutes of apnoea.
Secondary outcome [1] 313137 0
Our secondary outcomes will include difference in Fi02 levels after two minutes of apnoea, measured at the pharyngeal inlet by a gas sampling line.
Timepoint [1] 313137 0
Fi02 levels after two minutes of apnoea.
Secondary outcome [2] 313138 0
Our secondary outcomes will include a drop in oxygen saturations to <94% as measured by peripheral oximetry. If, at any point before the three minuted of apnoea has elapsed, the oxygen saturation falls below this level, the patient will be hand ventilated and efforts made to increase saturations or secure an definitive airway early.
Timepoint [2] 313138 0
Oxygen saturations falling at any point in the study to < 94% durng the three minutes prior to intubation.

Key inclusion criteria
Inclusion criteria include patient undergoing surgery at Southern Health, who are over or equal to 16 years of age, require intubation and paralysis for their surgery, who have pre-operative oxygen saturations >94% on room air and provide their informed consent to be included in the study.
Minimum age
16 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Exclusion criteria include patients less than 16 years of age, pregnant patients and those who have oxygen saturations on room air of less than 94%.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Allocation of the patient to ne of the two groups (Nasal prongs or nasopharyngeal cannula) will be by computer central randomisation.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
This will be achieved through simple randomisation using a randomisation table created by computer software.
Masking / blinding
Open (masking not used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Not Applicable
Type of endpoint(s)
Statistical methods / analysis
A power analysis has been performed. We will compare FiO2 between the intervention groups with a t-test. We consider a difference of 5% or more in FiO2 between nasal prongs and nasopharyngeal cannula to be clinically significant. So to look for a difference of 5%, with an estimated standard deviation of 5% in each group, and an alpha = 0.05 (two-sided) and 90% power we will need 22 patients in each intervention group. This gives a total recruitment of 44 patients.
We will perform a students t-test to compare the two groups and determine any clinical statistical significance.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment hospital [1] 3499 0
Monash Medical Centre - Clayton campus - Clayton
Recruitment hospital [2] 3500 0
Monash Medical Centre - Moorabbin campus - East Bentleigh
Recruitment postcode(s) [1] 9267 0
3168 - Clayton
Recruitment postcode(s) [2] 9268 0
3165 - Bentleigh East

Funding & Sponsors
Funding source category [1] 290798 0
Name [1] 290798 0
Department of Anaesthetics, Southern Health
Address [1] 290798 0
Department of Anaesthetics
Monash Medical Centre
246 Clayton Road
VIC 3168
Country [1] 290798 0
Primary sponsor type
Department of Anaesthetics, Southern Health
Department of Anaesthetics
Monash Medical Centre
246 Clayton Road
VIC 3186
Secondary sponsor category [1] 289478 0
Name [1] 289478 0
Address [1] 289478 0
Country [1] 289478 0

Ethics approval
Ethics application status
Ethics committee name [1] 292424 0
Monash HREC
Ethics committee address [1] 292424 0
Monash HREC
246 Clayton Road
Clayton VIC 3186
Ethics committee country [1] 292424 0
Date submitted for ethics approval [1] 292424 0
Approval date [1] 292424 0
Ethics approval number [1] 292424 0

Brief summary


The research project is comparing different devices for giving oxygen during the start of an anaesthetic. The different devices are called nasal prongs and nasopharyngeal cannula. Nasal prongs and nasopharyngeal cannula are already approved in Australia to supply Oxygen to patients in hospital.

All participants will receive Oxygen through a face mask before they are put to sleep for an operation. In addition, participants may receive additional Oxygen through nasal prongs or nasopharyngeal cannula. You will then be given anaesthetic medication and will go to sleep as normal. In this study, we would like to see how patients’ Oxygen levels in their throat change once they are asleep, enabling us to compare the different devices in terms of their effectiveness and the extent to which they can increase oxygen levels.
Our hypothesis is that each of the devices will increase Oxygen levels and we aim to determine if there is any difference between these two devices with respect which may be more effective at delivering Oxygen for this purpose.
Trial website
Trial related presentations / publications
Public notes
Attachments [1] 322 322 0 0
Attachments [2] 323 323 0 0
Attachments [4] 325 325 0 0

Principal investigator
Name 55222 0
Address 55222 0
Department of Anaesthetics
Monash Medical Centre
246 Clayton Road
VIC 3186
Country 55222 0
Phone 55222 0
Fax 55222 0
Email 55222 0
Contact person for public queries
Name 55223 0
Address 55223 0
Department of Anaesthetics
Monash Medical Centre
246 Clayton Road
VIC 3186
Country 55223 0
Phone 55223 0
+61 03 9594 6666 via switch
Fax 55223 0
Email 55223 0
Contact person for scientific queries
Name 55224 0
Address 55224 0
Department of Anaesthetics
Monash Medical Centre
246 Clayton Road
VIC 3186
Country 55224 0
Phone 55224 0
+61 3 9594 6666 via switch
Fax 55224 0
Email 55224 0

No information has been provided regarding IPD availability
Summary results
No Results