Asymmetrical High Flow Nasal Cannula and End-Expiratory Lung Impedance

NCT06674629 | Completed DMC

• 1 other identifier: #30102024
• Study Type: observational
• Target: 17
• Locations: 1 country
• Sites: 1

Brief Summary

Objective: The primary aim is to assess end-expiratory lung impedance (EELI) changes during the application of high-flow oxygen therapy using asymmetric nasal cannulae, comparing conditions with the mouth closed and open in healthy volunteers in various positions. The secondary objective includes evaluating respiratory rate, shortening fraction, and diaphragm excursion via ultrasound. Study Design: This is a prospective observational cohort study conducted in the Critical Care Unit of Sanatorio Parque Rosario from November 5 to December 31, 2024. It will involve 20 healthy adult volunteers without respiratory conditions, with informed consent obtained from all participants. Volunteers with contraindications for electrical impedance tomography (EIT) will be excluded. Methods: Equipment Used: PulmoVista 500 Dräger (EIT), AIRVO 2 (high-flow oxygen generator), asymmetric nasal cannula (Optiflow OPT 966), Toshiba iStyle ultrasound machine. Procedures: The study includes EELI measurements in different positions (semi-seated, supine Fowler, prone, and prone Fowler) with various high-flow oxygen settings (40 and 60 L/min). Diaphragm excursion and thickening will be assessed using ultrasound. Scenarios and Measurements: 17 different testing scenarios will be conducted, with 16 intervals for washout breathing at room air between scenarios. Data on EELI, respiratory rate, and diaphragm measurements will be collected.

Conditions

End-Expiratory Lung Impedance; Respiratory Rate; Diaphragm Thickness Fraction; Diaphragm Excursion

Keywords

High Flow Oxygen Therapy; End-Expiratory Lung Impedance; Respiratory rate; Diaphragm Thickness Fraction

Outcome Measures

Primary Outcomes (1)

• End-Expiratory Lung Impedance

  Variation of end-expiratory lung impedance in different positions and with different flows.

  From enrollment to the end of treatment at 2.30hours

Secondary Outcomes (3)

• Respiratory Rate

  From enrollment to the end of treatment at 2.30hours

• Diaphragm Thickness Fraction

  From enrollment to the end of treatment at 2.30hours

• Diaphragm excursion

  From enrollment to the end of treatment at 2.30hours

Study Arms (1)

Healthy Adult Volunteers

Healthy adult volunteers, all above 18 years of age, who provide informed consent.

Device: High flow oxygen therapy

Interventions

High flow oxygen therapy DEVICE

Application of high flow oxygen therapy through asymmetric cannula at 40 and 60 L/m

Healthy Adult Volunteers

Eligibility Criteria

• Age: 18 Years - 50 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Probability Sample

Study Population

healthy volunteers healthcare professionals working at Sanatorio Parque in Rosario, aged between 18 and 50 years, who sign the informed consent form and have no history of respiratory pathology (who are non-smokers and do not have a history of any type of respiratory disease).

You may qualify if:

• healthy volunteers between 18 and 50 years of age who sign the informed consent form, without respiratory pathology.

You may not qualify if:

• contraindication to implement electrical impedance tomography or high flow oxygen therapy

Sponsors & Collaborators

• Argentinian Intensive Care Society: lead

Study Sites (1)

Hospital Británico de Buenos Aires

Buenos Aires, Buenos Aires, 1425, Argentina

Location

Related Publications (10)

• Slobod D, Spinelli E, Crotti S, Lissoni A, Galazzi A, Grasselli G, Mauri T. Effects of an asymmetrical high flow nasal cannula interface in hypoxemic patients. Crit Care. 2023 Apr 18;27(1):145. doi: 10.1186/s13054-023-04441-6.

  PMID: 37072854 BACKGROUND

• Boscolo A, Pettenuzzo T, Zarantonello F, Sella N, Pistollato E, De Cassai A, Congedi S, Paiusco I, Bertoldo G, Crociani S, Toma F, Mormando G, Lorenzoni G, Gregori D, Navalesi P. Asymmetrical high-flow nasal cannula performs similarly to standard interface in patients with acute hypoxemic post-extubation respiratory failure: a pilot study. BMC Pulm Med. 2024 Jan 8;24(1):21. doi: 10.1186/s12890-023-02820-x.

  PMID: 38191347 BACKGROUND

• Tatkov S, Rees M, Gulley A, van den Heuij LGT, Nilius G. Asymmetrical nasal high flow ventilation improves clearance of CO2 from the anatomical dead space and increases positive airway pressure. J Appl Physiol (1985). 2023 Feb 1;134(2):365-377. doi: 10.1152/japplphysiol.00692.2022. Epub 2023 Jan 12.

  PMID: 36633864 BACKGROUND

• Roca O, Riera J, Torres F, Masclans JR. High-flow oxygen therapy in acute respiratory failure. Respir Care. 2010 Apr;55(4):408-13.

  PMID: 20406507 BACKGROUND

• Parke RL, Eccleston ML, McGuinness SP. The effects of flow on airway pressure during nasal high-flow oxygen therapy. Respir Care. 2011 Aug;56(8):1151-5. doi: 10.4187/respcare.01106. Epub 2011 Apr 15.

  PMID: 21496369 BACKGROUND

• Groves N, Tobin A. High flow nasal oxygen generates positive airway pressure in adult volunteers. Aust Crit Care. 2007 Nov;20(4):126-31. doi: 10.1016/j.aucc.2007.08.001. Epub 2007 Oct 10.

  PMID: 17931878 BACKGROUND

• Plotnikow GA, Thille AW, Vasquez DN, Pratto RA, Quiroga CM, Andrich ME, Dorado JH, Gomez RS, D'Annunzio PA, Scapellato JL, Intile D. Effects of High-Flow Nasal Cannula on End-Expiratory Lung Impedance in Semi-Seated Healthy Subjects. Respir Care. 2018 Aug;63(8):1016-1023. doi: 10.4187/respcare.06031. Epub 2018 Jun 26.

  PMID: 29945910 BACKGROUND

• Hernandez G, Vaquero C, Gonzalez P, Subira C, Frutos-Vivar F, Rialp G, Laborda C, Colinas L, Cuena R, Fernandez R. Effect of Postextubation High-Flow Nasal Cannula vs Conventional Oxygen Therapy on Reintubation in Low-Risk Patients: A Randomized Clinical Trial. JAMA. 2016 Apr 5;315(13):1354-61. doi: 10.1001/jama.2016.2711.

  PMID: 26975498 BACKGROUND

• Frat JP, Thille AW, Mercat A, Girault C, Ragot S, Perbet S, Prat G, Boulain T, Morawiec E, Cottereau A, Devaquet J, Nseir S, Razazi K, Mira JP, Argaud L, Chakarian JC, Ricard JD, Wittebole X, Chevalier S, Herbland A, Fartoukh M, Constantin JM, Tonnelier JM, Pierrot M, Mathonnet A, Beduneau G, Deletage-Metreau C, Richard JC, Brochard L, Robert R; FLORALI Study Group; REVA Network. High-flow oxygen through nasal cannula in acute hypoxemic respiratory failure. N Engl J Med. 2015 Jun 4;372(23):2185-96. doi: 10.1056/NEJMoa1503326. Epub 2015 May 17.

  PMID: 25981908 BACKGROUND

• Roca O, Hernandez G, Diaz-Lobato S, Carratala JM, Gutierrez RM, Masclans JR; Spanish Multidisciplinary Group of High Flow Supportive Therapy in Adults (HiSpaFlow). Current evidence for the effectiveness of heated and humidified high flow nasal cannula supportive therapy in adult patients with respiratory failure. Crit Care. 2016 Apr 28;20(1):109. doi: 10.1186/s13054-016-1263-z.

  PMID: 27121707 BACKGROUND

Related Links

• Drive Study link

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Hospital Británico de Buenos Aires

Study Record Dates

• First Submitted: November 4, 2024
• First Posted: November 5, 2024
• Study Start: November 5, 2024
• Primary Completion: December 31, 2024
• Study Completion: January 31, 2025
• Last Updated: July 2, 2025

Record last verified: 2025-06

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, ICF, CSR
• Time Frame: January 2025-January 2026

Locations

AR (1)