Healthy Volunteers
Conditions
Keywords
healthy volunteers, HFNC, high flow oxygen, oximetry, capnometry, pharyngeal
Brief summary
Observational, randomized studies and their meta-analyses have shown the high effectiveness of high-flow oxygen therapy through nasal cannulas, reaching 50-60% in acute hypoxemic respiratory failure. Some bench studies showed the advantages of high-flow oxygen therapy compared with standard oxygen therapy, consisting in reducing the anatomical dead space and maintaining a given inspiratory oxygen fraction in the hypopharynx of the mannequin, but the actual state of the gas composition of the hypopharynx was not studied. The study aim is measurement of the inspiratory (FiO2) and expiratory (FeO2) fractions of oxygen, as well as the inspiratory (FiСO2) and expiratory (FeСO2) fractions of carbon dioxide in the hypopharynx of healthy volunteers during high-flow oxygen therapy through nasal cannulas in different physiological conditions.
Detailed description
Randomized controlled trials showed reduction of tracheal intubation in high-flow oxygen therapy through nasal cannulas group in patients with acute respiratory failure as compared to standard oxygen therapy and noninvasive ventilation before Coronavirus disease-19 (COVID-19) pandemic. The World Health Organization (WHO) declared the outbreak a pandemic of COVID-19 on March 11th, 2020. Since then observational, randomized studies and their meta-analyses have shown the high effectiveness of high-flow oxygen therapy through nasal cannulas (HFNC), reaching 50-60% in acute hypoxemic respiratory failure. Bench studies showed the advantages of HFNC compared with standard oxygen therapy, consisting in reducing the anatomical dead space and maintaining a given inspiratory oxygen fraction in the hypopharynx of the mannequin, but the actual state of the gas composition of the hypopharynx during HFNC was not studied. The study aim is measurement of the inspiratory (FiO2) and expiratory (FeO2) fractions of oxygen, as well as the inspiratory (FiСO2) and expiratory (FeСO2) fractions of carbon dioxide in the hypopharynx of healthy volunteers during high-flow oxygen therapy through nasal cannulas in different physiological conditions.
Interventions
DEVICEHigh flow oxygen through nasal cannula
High flow oxygen through nasal cannula and measurement of oxygen and carbon dioxide fraction in the hypopharynx of healthy volunteers in different physiological conditions.
Sponsors
I.M. Sechenov First Moscow State Medical University
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
DEVICE_FEASIBILITY
Masking
NONE
Intervention model description
Measurement of the inspiratory (FiO2) and expiratory (FeO2) fractions of oxygen (FiСO2 and FeСO2, respectively), as well as the inspiratory and expiratory fractions of carbon dioxide (FiСO2 and FeСO2, respectively) in the hypopharynx of healthy volunteers during high-flow oxygen therapy through nasal cannulas in different physiological conditions
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
Inclusion criteria
* Healthy Volunteers * Age over 18 years * Written informed consent.
Exclusion criteria
* Any primary or secondary lung diseases (COPD, bronchial asthma, interstitial lung diseases, metastatic lung disease, lung cancer) * Any chronic diseases that can cause respiratory disorders (chronic heart failure, liver cirrhosis, systemic connective tissue diseases, cancer, neuromuscular diseases etc) * Heart rhythm disturbances * Body mass index more than 30 kg/m2 * Swallowing disorders * History of epileptic syndrome * Recent head surgery or anatomy that precludes the use of nasal cannulas * Pregnancy and lactation period * Inability to cooperate with staff.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Inspiratory oxygen fraction (FiO2) in the hypopharynx | 5 minutes | Inspiratory oxygen fraction (FiO2) in the hypopharynx during different physiological conditions |
| Expiratory oxygen fraction (FeO2) in the hypopharynx | 5 minutes | Expiratory oxygen fraction (FeO2) in the hypopharynx during different physiological conditions |
| Inspiratory fraction of carbon dioxide (FiCO2) in the hypopharynx | 5 minutes | Inspiratory fraction of carbon dioxide (FiCO2) in the hypopharynx during different physiological conditions |
| Expiratory fraction of carbon dioxide (FeCO2) in the hypopharynx | 5 minutes | Expiratory fraction of carbon dioxide (FeCO2) in the hypopharynx during different physiological conditions |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| The ratio of oxygen saturation by pulse oximetry/inspiratory oxygen fraction to respiratory rate (ROX-index) | 5 minutes | ROX-index (SpO2/FiO2/RR) during different physiological conditions |
| Respiratory rate (RR) | 5 minutes | Respiratory rate (RR) during different physiological conditions |
| Comfort | 5 minutes | Visual-analog scale (VAS) for comfort evaluation (from 1 to 10, 1-full comfort, 10-full comfort) |
| Tidal volume (VT) | 5 minutes | Tidal volume (VT) during different physiological conditions |
| Peripheral oxygen saturation (SpO2) | 5 minutes | Peripheral oxygen saturation (SpO2) during different physiological conditions |
| Modified ventilatory ratio (mVR) | 5 minutes | Modified ventilatory ratio (mVR) during different physiological conditions. mVR = \[RR \* tidal volume\* (PetCO2 (mmHg) - 4 mmHg)\] / \[predicted body weight (kg) \* 100 \* 37,5 mmHg\] |
Countries
Russia
Outcome results
None listed