Healthy Volunteers
Conditions
Keywords
High flow nasal cannula, Airway pressure, Lung volume, Non-invasive ventilation
Brief summary
Respiratory failure is characterized by low levels of oxygen and high levels of carbon dioxide in the blood which causes difficulty breathing. The management of patients with respiratory failure aims at improving oxygenation and changing the effort required to breathe. Mechanical ventilation is a life-saving treatment but may be associated with a high mortality rate, prolonged stay in the intensive care unit (ICU), and infection. Oxygenation techniques to avoid mechanical ventilation include standard oxygen therapy, continuous positive pressure (CPAP), and high-flow nasal cannula oxygen therapy (HFNC). CPAP consists of delivering oxygen through a mask. As compared to standard oxygen therapy, CPAP can promote lung recruitment leading to improved oxygenation and the effect in work of breathing in patients with respiratory failure. Conversely, high-flow nasal cannula oxygen therapy (HFNC) delivers oxygen through nasal prongs. Oxygen is heated and humidified and can be delivered at different flows (from 10 - 60 L/min). As compared to standard oxygen therapy, HFNC can promote some lung recruitment leading to mofiy oxygenation and work of breathing. Therefore, the present study will have 2 phases: Phase 1:Comparison of the physiological effects of different flows of HFNC to CPAP in healthy volunteers. The investigators hypothesized that the physiological effects of HFNC in the nasopharynx are comparable to that of CPAP at 4 cm H2O. Phase 2: Comparison of the physiological effects of different nasal interfaces of HFNC (Standard cannula vs. Asymmetrical cannula vs. Single-nostril adapted cannula) in healthy volunteers. The investigators hypothesized that the physiological effects of HFNC in the nasopharynx are comparable to that of CPAP at 4 cm H2O. It was hypothesized that asymmetrical which is the cannula that has a higher cross-sectional area generates higher nasal pharyngeal pressure.
Interventions
None listed
Sponsors
Unity Health Toronto
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Healthy volunteers ≥ 18 y-o, * No evidence of acute or chronic cardiopulmonary disease
Exclusion criteria
* Active epistaxis, sinus problem, nasal trauma, or deviated septum that would preclude the nasopharyngeal catheter insertion, * Pregnancy, clinical evidence of respiratory illness, history of respiratory disease, body mass of over 50 kg/m2, ribcage malformation, * Cardiac pace maker or implantable cardioverter-defibrillator according to EIT manufacturer, * Allergy to topical lidocaine, * Claustrophobia that would preclude the use of CPAP or HFNC.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| End expiratory nasopharyngeal pressure (NP) | 5 minutes | The primary endpoint is to compare the end expiratory nasopharyngeal pressure (NP) under 60 L/min of high flow nasal cannula (HFNC) to continuous positive airway pressure (CPAP 4 cmH2O).This will be assessed using a nasopharyngeal catheter. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in physiologic variables of airway pressure at different flows of HFNC (20, 40, and 60 L/min) and CPAP (4 cmH20). In the phase#2; HFNC 2, and 50 L/min. | 5 minutes | One of the secondary endpoints is to compare variables of airway pressure at different flows of HFNC to CPAP. The investigators will measure the end expiratory NP, mean NP, mean peak inspiratory pressure, mean peak expiratory pressure, delta inspiratory pressure and delta expiratory pressure. Each of these variables will be measured for 1 minute using a nasopharyngeal catheter. Furthermore, at each flow of HFNC, the investigators will ask the patient to breathe with their mouth open and mouth closed. |
| Change in end-expiratory lung impedance | 5 minnutes | The other secondary endpoint is to compare the change in ventilation distribution and end-expiratory lung impedance at different flows of HFNC and CPAP (Different nasal cannulas in the 2nd phase). These variables will be measured using electrical impedance tomography (EIT) by placing a band around the chest of each participant. |
| Dead-space washout in the upper airways | 5 minutes | Assess whether the transcutaneous CO2 is modified by HFNC, while comparing 3 different nasal cannulas (Symmetrical, Asymmetrical, Single-nostril adapted). |
Countries
Canada
Contacts
Primary ContactLaurent Brochard, MD
Backup ContactFrank Silva Bezerra, PhD
Outcome results
None listed