None listed
Conditions
Brief summary
High flow humidified nasal oxygen therapy (HFNOT) is a recent development that allows the provision of controlled oxygen concentrations and low levels of positive airway pressure via a nasal interface. The HFNOT system can offer clinicians and patients a different mechanism for delivering such pressure, at low levels, without some of the complications and comfort issues associated with these other methods. Some of the reported risks associated with face mask non invasive ventilation include mask discomfort, nasal dryness, oral dryness and eye irritation nasal or eye trauma and gastric distension / aspiration. Over the last three years there have been several studies published regarding the effectiveness and the clinical effect of this new form of respiratory support. Currently HFNOT is used as the standard therapy in patients with mild to moderate hypoxemic respiratory failure requiring respiratory support following extubation to improve oxygenation in patients in the Cardiothoracic and Vascular Intensive Care Unit at Auckland City Hospital. Research conducted previously by our group and others has demonstrated a positive linear correlation between the amount of flow and the resulting airway pressure with flows in the range described above. Since it is technically possible to apply higher flows with HFNOT devices we would like to describe the resulting changes in airway pressure and to see if the correlation remains linear at flows exceeding 50L/min and would like to conduct an initial study on 15 healthy volunteers.
Interventions
15 healthy subjects will be included in this study.
A 10 F catheter will be inserted into the hypopharynx via the nose. Following this the position of the tube will be confirmed using end tidal CO2 monitoring as well as a visual inspection.
Following the diagnostic setup they will be attached to the Optiflow TRADEMARK system comprising the Fisher and Paykel Healthcare MR880 humidifier delivering gas heated and humidified to 37degrees C, 44mg H2O/L. The heated circuit will comprise an RT241 c
15 healthy subjects will be included in this study. A 10 F catheter will be inserted into the hypopharynx via the nose. Following this the position of the tube will be confirmed using end tidal CO2 monitoring as well as a visual inspection. Following the diagnostic setup they will be attached to the Optiflow TRADEMARK system comprising the Fisher and Paykel Healthcare MR880 humidifier delivering gas heated and humidified to 37degrees C, 44mg H2O/L. The heated circuit will comprise an RT241 circuit, an MR290 autofeed chamber and an appropriately sized adult nasal interface. Subjects will also be assessed with EIT. For this purpose there will be a circumferential placement of a 16 electrode belt applied around the torso. The electrodes will be attached to the skin and can be removed without resulting damage or discomfort at any stage. Participants will have pressure measurements carried out at 30, 40, 50, 60, 70, 80, 90 and 100 L/min in random order. Pressure measurement for each flow will be recorded over one minute of breathing using precision pressure transducer (PPT). This procedure is expected to take around 60 mins. The catheter will be removed at the end of this period. Hypopharyngeal pressure will be measured using a Honeywell precision pressure transducer (PPT – 0001 DWWW2VA-B, Honeywell International Ltd) with a laptop computer interface. The hypopharyngeal pressures will be recorded over one minute of breathing. The mean airway pressure will be determined by averaging the pressure from the peak of inspiration of the first to the last breath within the one minute recording. This will allow the entire pressure profile of each breath to be included within the mean airway pressure calculation.
Sponsors
Rachael Parke
Study design
Allocation
Non-randomised trial
Primary purpose
Treatment
Eligibility
Sex/Gender
All
Age
18 Years to 99 Years
Healthy volunteers
Yes
Inclusion criteria
Healthy subjects are eligible for inclusion if all of the following criteria are met: The subject is 18 years or older; Consent has been obtained;There are no known intrathoracic pathologies known ; The subject is not on any regular medication which is known to affect the cardiopulmonary system in any way
Exclusion criteria
Healthy subjects will be excluded from the study if one or more of the following criteria are present: The subject has significant nasal septum deviation; High flow nasal oxygen therapy is contraindicated.
Outcome results
None listed