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

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. Identifier: NCT01672242
Recruitment Status : Completed
First Posted : August 24, 2012
Results First Posted : January 10, 2018
Last Update Posted : February 7, 2018
Vapotherm, Inc.
Information provided by (Responsible Party):
Carl Shanholtz, University of Maryland

Brief Summary:

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 or disease Intervention/treatment Phase
Healthy Adult Volunteers Device: HFNC Device: CPAP Not Applicable

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 fraction of inspired oxygen (FiO2), hyperventilation, ventilation-perfusion (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 positive end expiratory pressure (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.

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 6 participants
Allocation: Randomized
Intervention Model: Crossover 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®)
Study Start Date : July 2012
Actual Primary Completion Date : April 2014
Actual Study Completion Date : April 2014

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Oxygen Therapy

Arm Intervention/treatment
Experimental: HFNC
High Flow Nasal Cannula (HFNC) oxygen.
Device: HFNC
Graded high flow nasal cannula oxygen at 10, 20 , 30, and 40 liters per minute (LPM) to each subject and end-expiratory lung volume measured by respiratory inductive plethysmography.
Other Name: High flow nasal cannula oxygen, Precision Flow®, Vapotherm®

Experimental: CPAP
Continuous Positive Airway Pressure (CPAP)
Device: CPAP
Graded contiuous positive airway pressure at 5, 10 , 15, and 20 cm H2O applied to each subject and end-expiratory lung volume measured by respiratory inductive plethysmography.
Other Name: Continuous positive airway pressure, Respironics(R)

Primary Outcome Measures :
  1. Change in End-expiratory Lung Volume [ Time Frame: baseline and after 3-5 minutes after each level of flow or pressure ]
    Change in end-expiratory lung volume from baseline arbitrarily set at 0 mL.

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 75 Years   (Adult, Older Adult)
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 ratio of forced expiratory volume at 1 second/forced vital capacity (FEV1/FVC) <70 when undergoing spirometry

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 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

Responsible Party: Carl Shanholtz, Associate Professor of Medicine, University of Maryland Identifier: NCT01672242     History of Changes
Other Study ID Numbers: HP-00052656
First Posted: August 24, 2012    Key Record Dates
Results First Posted: January 10, 2018
Last Update Posted: February 7, 2018
Last Verified: February 2018