Single-Breath Measurement Underestimates Ventilatory Volume According to Emphysema Severity

July 2, 2015 updated by: Columbia University
Although single breath helium (He) dilution measurement (VASB) is currently used in pulmonary function laboratories to assess functional alveolar volume and diffusing capacity for carbon monoxide, the extent to which VASB reflects ventilatory and thoracic volume has not been prospectively determined in emphysema. We hypothesized that VASB underestimates rebreathe helium dilution volume (VARB), and plethysmographic volume (VApleth) as clinical and physiologic severity of emphysema increases.

Study Overview

Status

Completed

Conditions

Detailed Description

VASB, VARB, and VApleth were measured in 52 consecutive stable outpatients with clinical and radiographic emphysema. Thirteen patients with an obstructive ventilatory defect without emphysema (OVD) and 18 normal controls were similarly studied. All subjects underwent spirometry followed by whole body plethysmography and He dilution volume measurements; VASB and VARB order was randomized.

Study Type

Observational

Enrollment (Actual)

73

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • New York
      • NY, New York, United States, 10032
        • Columbia University Cardiopulmonary, Sleep and Ventilatory Disorders Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 81 years (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

This is a prospective trial in all outpatients with emphysema referred for full pulmonary function testing to the pulmonary diagnostic unit.

Description

Inclusion Criteria:

  • All outpatients between the ages of 18 and 81 years referred to the Columbia University Medical Center Pulmonary Diagnostic Unit between 1/18/06 and 7/30/07 for full pulmonary function evaluation, and with an obstructive ventilatory defect on spirometry, were considered eligible.

Exclusion Criteria:

  • Patients who did not want to undergo the re-breathe diffusing capacity testing
  • Patients who could not give informed consent;and
  • Patients who were too physically compromised to undergo full testing including the re-breathe maneuver as deemed by our technicians.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Cohort A
Patients with obstructive defects and radiological evidence of emphysema
Cohort B
Patients with obstructive ventilatory defects and no radiological evidence of emphysema
Cohort C
Non-smokers without obstructive ventilatory defects or history of cardiopulmonary disease

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Difference between DLCO SB alveolar volume and the total lung volume measurement from plethysmography
Time Frame: 10 seconds
To test the hypothesis that DLCO SB underestimates DLCO derived by the re-breathe DLCO maneuver, and that VA SB similarly underestimates VA RB. Alveolar volume derived with the two maneuvers will be compared with body plethysmography, the gold standard of total lung volume measurement in patients with emphysema.
10 seconds
Difference between DLCO RB alveolar volume and the total lung volume measurement from plethysmography
Time Frame: 10 seconds
To test the hypothesis that DLCO SB underestimates DLCO derived by the re-breathe DLCO maneuver, and that VA SB similarly underestimates VA RB. Alveolar volume derived with the two maneuvers will be compared with body plethysmography, the gold standard of total lung volume measurement in patients with emphysema.
10 seconds

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Columbia University

Investigators

  • Principal Investigator: Robert C Basner, MD, Columbia University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

January 1, 2006

Primary Completion (Actual)

July 1, 2008

Study Completion (Actual)

July 1, 2008

Study Registration Dates

First Submitted

September 11, 2007

First Submitted That Met QC Criteria

September 12, 2007

First Posted (Estimate)

September 14, 2007

Study Record Updates

Last Update Posted (Estimate)

July 7, 2015

Last Update Submitted That Met QC Criteria

July 2, 2015

Last Verified

July 1, 2015

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • AAAB6328

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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