None listed
Conditions
Brief summary
We aim to measure the adequacy of preoxygenation by NRB and BVM in the abscence and presence of a simulated mask leak, and whether the addition of oxygen via NP significantly improves preoxygenation in these conditions, as measured by ETO2. We propose to perform a four-period crossover study (repeated measures design) with two arms, using healthy volunteers. There will be a NRB arm and BVM arm. After informed consent participants with be randomised to NRB and BVM. They will then be randomised to a sequence of 3minutes preoxygenation using the NRB, NRB+NP, NRB and simulated leak, NRB+NP and simulated leak in the NRB arm; or BVM, BVM+NP, BVM and simulated leak, BVM+NP and simulated leak in the BVM arm. ETO2 and endtidal carbon dioxide (ETCO2) will be measured using the gas sample analyser on an anaesthetic machine. Participants will also be asked to rate their comfort with each preoxygenation method.
Interventions
The study design is four-period crossover study (repeated measures design) with two arms. There will be a non-rebreather arm and BVM arm, participants will be randomly allocated to either arm. Each participant will be required to complete four trials of 3-minutes pre-oxygenation with 100% oxygen in only one of the arms (mask alone, mask and nasal-prongs, mask and nasal-prongs with leak, mask alone with leak). The simulated leak will be created using 16F nasogastric tube taped to both sides of th
The study design is four-period crossover study (repeated measures design) with two arms. There will be a non-rebreather arm and BVM arm, participants will be randomly allocated to either arm. Each participant will be required to complete four trials of 3-minutes pre-oxygenation with 100% oxygen in only one of the arms (mask alone, mask and nasal-prongs, mask and nasal-prongs with leak, mask alone with leak). The simulated leak will be created using 16F nasogastric tube taped to both sides of the mask. At the end of each trial oxygen will be measured by an expiratory breath into an oxygen analyser. This will be followed by a washout period of 2 minutes after which the ETO2 will be remeasured to ensure it is within 1% of the participants baseline. The sequence of the trials will be randomised in a balanced design.
Sponsors
St George Hospital
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Open (masking not used)
Eligibility
Sex/Gender
All
Age
18 Years to 70 Years
Healthy volunteers
Yes
Inclusion criteria
No regular cardiovascular or respiratory medication, no history of chronic respiratory disease. Employees of St George Hospital. We are currently not allowed to recruit outside of this site.
Exclusion criteria
Pregnancy, lung disease, known or suspected coronary or cerebrovascular disease, treatment for asthma or COPD, previous exposure to bleomycin, participants with beards, dentures or facial abnormalities affecting mask seal.
Outcome results
None listed