Single-Breath Measurement Underestimates Ventilatory Volume According to Emphysema Severity

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.

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Key information

Conditions

Emphysema Pathologic Processes Pathological Conditions, Signs and Symptoms

Age range

18 year–81 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Columbia University Cardiopulmonary, Sleep and Ventilatory Disorders Center

New York, 10032, United States

About this study

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.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

Primary outcomes

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.
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.

Sponsors and collaborators

Lead sponsor

Columbia University

Other

Registry information

Important dates

Study start: 2006
Primary completion: 2008
Study completion: 2008
First posted: Sep 14, 2007
Registry last updated: Jul 7, 2015

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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