EIT Assessment of Lung Volume and Tidal Distribution: A Comparison of Non-Invasive Ventilation Devices

This study is being done to further the investigators' knowledge of the EIT system and to see if measures between two non-invasive ventilation systems routinely used clinically are equivalent.

Study Overview

• Status: Completed
• Conditions: Spontaneous Ventilation
• Intervention / Treatment: Device: noninvasive positive pressure ventilation

Detailed Description

Mechanical ventilation is life-saving technology but it can also inadvertently induce lung injury and increase morbidity and mortality. There currently is not an easy method of assessing the impact ventilator settings have on the degree of lung inflation. Computed tomography (CT), the gold standard for visually monitoring lung function, can provide detailed regional information of the lung. Unfortunately, it necessitates moving critically ill patients to a special diagnostic room and involves exposure to radiation like an X-ray.

A technique introduced in the 1980's, electrical impedance tomography (EIT), can non-invasively provide similar monitoring of lung function, and without the exposure to radiation. This imaging technique applies small alternating currents of electricity to surface electrodes to construct cross-sectional images of the lung.

Over that past several decades EIT has moved from the research lab to commercially available devices that are used at the bedside. EIT has also been applied to study the effects of various devices used to provide non-invasive ventilation. EIT may prove useful to optimally adjust non-invasive ventilation settings to improve ventilation and oxygenation. One such EIT system is manufactured by Draeger Medical. It is available in Europe and Canada but is not yet FDA approved for use in the United States.

This study is being done with healthy volunteers to further the investigators' knowledge of the EIT system and to see if measures between two non-invasive ventilation systems routinely used clinically are equivalent.

As this is a preliminary study looking at the EIT system vs 2 other devices, outcomes measures may be modified as the study progresses.

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Michigan
    • Ann Arbor, Michigan, United States, 48109
      • University of Michigan

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Age 18 years or older

Exclusion Criteria:

• Use of a cardiac pacemaker, an implantable cardioverter-defibrillator (ICD) or any other active implants

Study Plan

How is the study designed?

Design Details

• Primary Purpose: OTHER
• Allocation: RANDOMIZED
• Interventional Model: CROSSOVER
• Masking: NONE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
ACTIVE_COMPARATOR: Respironics V-60, then Draeger V500; Testing by applying noninvasive positive pressure ventilation (NPPV) via two different bilevel positive airway pressure (BiPAP) devices . Arm one applies the Respironics V-60, then the Drager V-500.	Device: noninvasive positive pressure ventilation; Application of various levels of positive pressure
ACTIVE_COMPARATOR: Draeger V500, then Respironics V-60; Testing by applying noninvasive positive pressure ventilation (NPPV) via two different bilevel positive airway pressure (BiPAP) devices . Arm two applies the Drager V-500, then the Respironics V-60.	Device: noninvasive positive pressure ventilation; Application of various levels of positive pressure

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Global Tidal Variation (TID)	TID is the distribution of ventilation for a breath averaged over a defined section, the entire lung. TID is analogous to the tidal volume. Baseline is defined to be 100% and other measures are in comparison to baseline (eg, a value of 102 represents a 2% increase from baseline).	1 day

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Regional Tidal Variation: Dorsal	Distribution of ventilation for a breath averaged over a defined section, the dorsal lung regions. Reflects the percent of tidal volume distributed to that area.	1 day
Regional Tidal Variation: Ventral	Distribution of ventilation for a breath averaged over a defined section, the ventral lung regions. Reflects the percent of tidal volume distributed to that area.	1 day
Global Change in End-expiratory Lung Impedance (EELI)	EELI is the impedance at the end of tidal variation, or end-expiration. EELI reflects the end-expiratory lung volume (EELV); thus an increase in EELI represents and increase in lung volume. The change in EELI that the electrical impedance tomography (EIT) device (Pulmovista, Drager) provides is the percent difference between the EELI of a given period and the EELI during a baseline or reference period. Positive or negative percent change suggests an increase or decrease in EELI and presumably EELV by a similar percentage. The baseline measurements used here were taken breathing air and no pressures applied, while the other measurements were taken with varying levels of pressure applied. By definition, baseline is assigned the value of 0%, by the EIT device. While it would be helpful to have the actual numbers for the baseline impedance values, this data was not provided by the EIT device.	1 day
Regional Change in EELI: Dorsal	EELI is the impedance at the end of tidal variation, or end-expiration. EELI reflects the end-expiratory lung volume (EELV); thus an increase in EELI represents and increase in lung volume. The change in EELI that the electrical impedance tomography (EIT) device (Pulmovista, Drager) provides is the percent difference between the EELI of a given period and the EELI during a baseline or reference period. Positive or negative percent change suggests an increase or decrease in EELI and presumably EELV by a similar percentage. The baseline measurements used here were taken breathing air and no pressures applied, while the other measurements were taken with varying levels of pressure applied. By definition, baseline is assigned the value of 0%, by the EIT device. While it would be helpful to have the actual numbers for the baseline impedance values, this data was not provided by the EIT device	1 day
Regional Change in EELI: Ventral	EELI is the impedance at the end of tidal variation, or end-expiration. EELI reflects the end-expiratory lung volume (EELV); thus an increase in EELI represents and increase in lung volume. The change in EELI that the electrical impedance tomography (EIT) device (Pulmovista, Drager) provides is the percent difference between the EELI of a given period and the EELI during a baseline or reference period. Positive or negative percent change suggests an increase or decrease in EELI and presumably EELV by a similar percentage. The baseline measurements used here were taken breathing air and no pressures applied, while the other measurements were taken with varying levels of pressure applied. By definition, baseline is assigned the value of 0%, by the EIT device. While it would be helpful to have the actual numbers for the baseline impedance values, this data was not provided by the EIT device	1 day

Collaborators and Investigators

• Sponsor: University of Michigan
• Investigators: Principal Investigator: Carl Haas, MLS, University of Michigan

Study record dates

Study Major Dates

• Study Start (ACTUAL): February 1, 2018
• Primary Completion (ACTUAL): March 27, 2018
• Study Completion (ACTUAL): March 27, 2018

Study Registration Dates

• First Submitted: August 24, 2015
• First Submitted That Met QC Criteria: October 7, 2016
• First Posted (ESTIMATE): October 12, 2016

Study Record Updates

• Last Update Posted (ACTUAL): May 14, 2019
• Last Update Submitted That Met QC Criteria: May 3, 2019
• Last Verified: May 1, 2019

More Information

Terms related to this study

• Other Study ID Numbers: HUM00102144

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No