Clinical trial NCT03902639: Examining the Effects of Nasal High Flow Oxygen Therapy Compared to Non-invasive Ventilation in Health Volunteers
Official title: Comparative Study of the Physiological Effects of High Flow Nasal Cannula and Non-invasive Ventilation in Healthy Volunteers
Study type: OBSERVATIONAL
Overall status: RECRUITING
Conditions: Healthy Volunteers
Keywords: High flow nasal cannula
Airway pressure
Lung volume
Non-invasive ventilation
Lead sponsor: Unity Health Toronto
Sponsor class: OTHER
First posted: 2019-04-04
Enrollment: 10
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Healthy volunteers responding to advertisement posted through the St. Michael's Hospital Communications board.

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.


Eligibility criteria: 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.

Primary outcomes:
measure: End expiratory nasopharyngeal pressure (NP)
timeFrame: 5 minutes
measure: End expiratory nasopharyngeal pressure (NP)
timeFrame: 5min
Secondary outcomes:
measure: 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.
timeFrame: 5 minutes
measure: Change in end-expiratory lung impedance
timeFrame: 5 minnutes
measure: Dead-space washout in the upper airways
timeFrame: 5 minutes
Other outcomes:
Locations:
city: Toronto
country: Canada
facility: St. Michael's Hospital
state: Ontario
Study officials:
affiliation: Unity Health Toronto
name: Laurent Brochard, MD
role: PRINCIPAL_INVESTIGATOR
References: