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Assessment of End Expiratory Lung Volumes in Healthy Subjects Using High Flow Oxygen (Vapotherm®)

This study has been completed.
ClinicalTrials.gov Identifier:
First Posted: August 24, 2012
Last Update Posted: April 29, 2014
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Vapotherm, Inc.
Information provided by (Responsible Party):
Carl Shanholtz, University of Maryland

Respiratory distress is a common problem in an intensive care unit. There are multiple mechanisms that are used to help patients who are in respiratory distress including mechanical ventilation, continuous positive airway pressure (CPAP), bilevel positive airway pressure (BiPAP), high flow oxygen, and oxygen supplementation through nasal cannula or a facemask.

The purpose of this study is to evaluate the mechanism by which Vapotherm, a high flow oxygen system, provides breathing support. Vapotherm provides high flow oxygen at different flow rates, meaning one can increase the amount of oxygen flow to help with breathing support. The investigators believe that this high flow oxygen system may provide similar breathing support that a continuous positive airway pressure machine (CPAP) machine does.

Condition Intervention Phase
Healthy Adult Volunteers Device: High-flow nasal cannula oxygen Device: Facial CPAP Phase 4

Study Type: Interventional
Study Design: Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Basic Science
Official Title: Assessment of End Expiratory Lung Volumes in Healthy Subjects Using High Flow Oxygen (Vapotherm®)

Resource links provided by NLM:

Further study details as provided by Carl Shanholtz, University of Maryland:

Primary Outcome Measures:
  • End-expiratory lung volume [ Time Frame: 6 hours ]

Enrollment: 6
Study Start Date: July 2012
Study Completion Date: April 2014
Primary Completion Date: April 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Non-invasive ventilation
Graded high flow nasal cannula oxygen and facial CPAP will be randomly applied to each subject and end-expiratory lung volume measured by respiratory inductive plethysmography.
Device: High-flow nasal cannula oxygen
Graded levels of HFNC will be applied and end-expiratory lung volumes measured by respiratory inductive plethysmography
Other Name: Precision Flow®, Vapotherm®, Stevensville, MD
Device: Facial CPAP
Graded levels of CPAP will be applied by face mask and end-expiratory lung volumes measured by respiratory inductive plethysmography
Other Name: Respironics

Detailed Description:

High flow nasal cannula oxygen therapy (HFNC) is a method of oxygen delivery now commonly used in persistently hypoxic patients refractory to conventional modes of oxygen supplementation (i.e. nasal cannula, facemask, non-rebreather facemask). Initially used in neonates, it is now increasingly popular in the adult population. While the investigators know how HFNC provides oxygen supplementation, the physiologic mechanism of correcting hypoxemia is still unclear. There are five mechanisms of hypoxemia, four which correct with oxygen supplementation - decreased FiO2, hyperventilation, V/Q mismatch, and diffusion defect; and one that does not - shunt. The hypoxemia refractory to supplemental oxygen suggests the presence of physiologic shunt. The conventional non-invasive therapy to reduce shunt fraction requires raising end-expiratory lung volumes by raising end-expiratory airway pressures using the application of continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP). The Vapotherm® (Vapotherm®, Stevensville, Maryland) product of high flow oxygen therapy (Precision Flow®) is one the investigators frequently use in intensive care units at the University of Maryland Medical Center. It does not create a leak proof seal in the nose as seen in CPAP and BiPAP. Positive pressure generation has been studied in another high flow oxygen system called Optiflow™ (Fisher & Paykel Healthcare, Ltd., Auckland, New Zealand). However this device differs from Vapotherm® in that its nasal bores are large and create a seal in each nares thereby affected both ventilation and the level of PEEP generation. Additionally, these studies measured positive expiratory lung pressures, not volume. Positive end expiratory alveolar pressure and increase expiratory lung volumes in adults have not yet been demonstrated using Precision Flow®.

HFNC is intriguing because studies and clinical data have shown it is a relatively non-invasive method of oxygen delivery that appears to correct hypoxemia better than other non-invasive methods. It is more comfortable than a CPAP machine and thus is better tolerated among patients, especially those who are critically ill and possibly altered. While it has been used in neonates for some time, its use with adults is new and needs more research.

The investigators hypothesis is that HFNC corrects persistent hypoxemia by producing increased end-expiratory lung volumes thus keeping alveoli open throughout the respiratory cycle which other oxygen supplements are unable to do. Using healthy volunteers the investigators will measure end expiratory lung volumes on HFNC and compare them to those obtained with CPAP at graded pressures.


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Ages Eligible for Study:   18 Years to 75 Years   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Age between 18 and 75
  • Able to follow and understand simple instructions to collect spirometry

Exclusion Criteria:

  • Younger than 18y/o
  • Older than 75 years old
  • History of chronic obstructive pulmonary disease (COPD)
  • History of asthma
  • History of congestive heart failure
  • Measured FEV1/FVC <70 when undergoing spirometry
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01672242

United States, Maryland
University of Maryland School of Medicine
Baltimore, Maryland, United States, 21201
Sponsors and Collaborators
University of Maryland
Vapotherm, Inc.
Principal Investigator: Carl B. Shanholtz, MD University of Maryland
  More Information

Responsible Party: Carl Shanholtz, Associate Professor of Medicine, University of Maryland
ClinicalTrials.gov Identifier: NCT01672242     History of Changes
Other Study ID Numbers: HP-00052656
First Submitted: August 9, 2012
First Posted: August 24, 2012
Last Update Posted: April 29, 2014
Last Verified: April 2014