Gas Composition in the Oropharynx During High-flow Oxygen Therapy Through Nasal Cannula in Healthy Volunteers

Not Applicable

Completed

• Conditions: Healthy Volunteers
• Interventions: Device: High flow oxygen through nasal cannula

• Registration Number: NCT06189716
• Lead Sponsor: I.M. Sechenov First Moscow State Medical University

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.

Study Timeline

• Status Verified: 2023-12
• Study First Submitted: 2023-12-19
• Study First Submitted QC: 2023-12-19
• Study First Posted: 2024-01-03
• Study Start: 2024-01-09
• Primary Completion: 2024-04-30
• Study Completion: 2024-06-10
• Last Update Submitted: 2024-10-03
• Last Update Posted: 2024-10-07

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 20

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.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Experimental	High flow oxygen through nasal cannula	High flow oxygen through nasal cannula, oxygen and carbon dioxide measurement in the hypopharynx

Primary Outcome Measures

Name	Time	Method
Inspiratory oxygen fraction (FiO2) in the hypopharynx	5 minutes	Inspiratory oxygen fraction (FiO2) 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 oxygen fraction (FeO2) in the hypopharynx	5 minutes	Expiratory oxygen fraction (FeO2) 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 Outcome Measures

Name	Time	Method
Respiratory rate (RR)	5 minutes	Respiratory rate (RR) during different physiological conditions
Tidal volume (VT)	5 minutes	Tidal volume (VT) during different physiological conditions
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
Comfort	5 minutes	Visual-analog scale (VAS) for comfort evaluation (from 1 to 10, 1-full comfort, 10-full comfort)
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 = \[RR \* tidal volume\* (PetCO2 (mmHg) - 4 mmHg)\] / \[predicted body weight (kg) \* 100 \* 37,5 mmHg\]

Trial Locations

Locations (1)

Sechenov University Clinic#4; 🇷🇺 Moscow, Russian Federation