Effect of Very-High-Flow Nasal Therapy on Airway Pressure and End-Expiratory Lung Impedance in Healthy Volunteers

Parke, Rachael L.
October 2015
Respiratory Care;Oct2015, Vol. 60 Issue 10, p1397
Academic Journal
BACKGROUND: Previous research has demonstrated a positive linear correlation between flow delivered and airway pressure generated by high-flow nasal therapy. Current practice is to use flows over a range of 30-60 L/min; however, it is technically possible to apply higher flows. In this study, airway pressure measurements and electrical impedance tomography were used to assess the relationship between flows of up to 100 L/min and changes in lung physiology. METHODS: Fifteen healthy volunteers were enrolled into this study. A high-flow nasal system capable of delivering a flow of 100 L/min was purpose-built using 2 Optiflow systems. Airway pressure was measured via the nasopharynx, and cumulative changes in end-expiratory lung impedance were recorded using the PulmoVista 500 system at gas flows of 30-100 L/min in increments of 10 L/min. RESULTS: The mean age of study participants was 31 (range 22-44) y, the mean ± SD height was 171.8 ± 7.5 cm, the mean ± SD weight was 69.7 ± 10 kg, and 47% were males. Flows ranged from 30 to 100 L/min with resulting mean ± SD airway pressures of 2.7 ± 0.7 to 11.9 ± 2.7 cm H2O. A cumulative and linear increase in end-expiratory lung impedance was observed with increasing flows, as well as a decrease in breathing frequency. CONCLUSIONS: Measured airway pressure and lung impedance increased linearly with increased gas flow. Observed airway pressures were in the range used clinically with face-mask noninvasive ventilation. Developments in delivery systems may result in this therapy being an acceptable alternative to face-mask noninvasive ventilation.


Related Articles

  • Evaluation of a Nasal Cannula in Noninvasive Ventilation Using a Lung Simulator. Iyer, Narayan P; Chatburn, Robert // Respiratory Care;Apr2015, Vol. 60 Issue 4, p508 

    BACKGROUND: Nasal noninvasive ventilation (NIV) is a common form of noninvasive respiratory mode used in newborn infants. A next-generation nasal cannula (Neotech RAM cannula) has recently been used to provide nasal NIV. The impact of the Neotech RAM cannula on the delivery of pressure needs to...

  • Effect of High-Flow Nasal Cannula and Body Position on End-Expiratory Lung Volume: A Cohort Study Using Electrical Impedance Tomography. Riera, Jordi; Perez, Purificacion; Cort´s, Jordi; Roca, Oriol; Masclans, Joan Ramon; Rello, Jordi // Respiratory Care;Apr2013, Vol. 58 Issue 4, p589 

    BACKGROUND: Electrical impedance tomography measures changes in lung impedance, which are mainly related to changes in lung volume. We used electrical impedance tomography to investigate the effects of high-flow nasal cannula (HFNC) and body position on global and regional end-expiratory lung...

  • Pressures Delivered By Nasal High Flow Oxygen During All Phases of the Respiratory Cycle. Parke, Rachael L.; Mcguinness, Shay P. // Respiratory Care;Oct2013, Vol. 58 Issue 10, p1621 

    BACKGROUND: Nasal high flow (NHF) oxygen therapy and CPAP are modes of noninvasive respiratory support used to improve respiratory function in multiple patient groups. Both therapies provide positive pressure, although this varies during the respiratory cycle. The purpose of this study was to...

  • Estimating daily energy expenditure in individuals with amyotrophic lateral sclerosis. Kasarskis, Edward J.; Mendiondo, Marta S.; Matthews, Dwight E.; Hiroshi Mitsumoto; Tandan, Rup; Simmons, Zachary; Bromberg, Mark B.; Kryscio, Richard J. // American Journal of Clinical Nutrition;Apr2014, Vol. 99 Issue 4, p792 

    Background: Patients with amyotrophic lateral sclerosis (ALS) experience progressive limb weakness, muscle atrophy, and dysphagia, making them vulnerable to insufficient energy intake. Methods to estimate energy requirements have not been devised for this patient group. Objective: The goal was...

  • Diagnosis of Breast Cancer Using Electrical Impedance Tomography. Pak, D.; Rozhkova, N.; Kireeva, M.; Ermoshchenkova, M.; Nazarov, A.; Fomin, D.; Rubtsova, N. // Biomedical Engineering;Nov2012, Vol. 46 Issue 4, p154 

    The efficiency of electrical impedance tomography, a new method of breast cancer diagnosis, is considered in this work. A total of 117 female patients (apparently healthy, patients with mastopathy, patients with benign tumors, patients with breast cancer) were tested. The method was implemented...

  • Characterization of Maximal Respiratory Pressures in Healthy Children. Cox, Desmond W.; Verheggen, Maureen M.; Stick, Stephen M.; Hall, Graham L. // Respiration;2012, Vol. 84 Issue 6, p485 

    Background: Measurements of maximal voluntary inspiratory (Pimax) and expiratory (Pemax) pressures are used in the management of respiratory muscle disease. There is little data on the appropriate reference range, success rates, or repeatability of Pimax and Pemax in children or on...

  • Demographic, Military, and Health Characteristics of VA Health Care Users and Nonusers Who Served in or During Operation Enduring Freedom or Operation Iraqi Freedom, 2009-2011. Dursa, Erin K.; Barth, Shannon K.; Bossarte, Robert M.; Schneiderman, Aaron I. // Public Health Reports;Nov/Dec2016, Vol. 131 Issue 6, p839 

    An estimated 60% of all Operation Enduring Freedom / Operation Iraqi Freedom (OEF/OIF) veterans who have left the military had used the US Department of Veterans Affairs (VA) for health care services as of March 31, 2015. What is not known, however, are the differences in demographic, military,...

  • Humidification of Inspired Oxygen Is Increased With Pre-nasal Cannula, Compared to Intranasal Cannula. Dellweg, Dominic; Wenze, Markus; Hoehn, Ekkehard; Bourgund, Olaf; Haidl, Peter // Respiratory Care;Aug2013, Vol. 58 Issue 8, p1323 

    BACKGROUND: Oxygen therapy is usually combined with a humidification device, to prevent mucosal dryness. Depending on the cannula design, oxygen can be administered pre- or intranasally (administration of oxygen in front of the nasal ostia vs cannula system inside the nasal vestibulum). The...

  • Effects of Breathing Pattern on Oxygen Delivery Via a Nasal or Pharyngeal Cannula. Natsuhiro Yamamoto; Tetsuya Miyashita; Shunsuke Takaki; Takahisa Goto // Respiratory Care;Dec2015, Vol. 60 Issue 12, p1804 

    BACKGROUND: During sedation for upper gastrointestinal endoscopy, oxygen delivery via a nasal cannula is often necessary. However, the influences of the oxygen delivery route and breathing pattern on the FIO have not been thoroughly investigated. The aim of this simulation study was to...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics