Single-Breath Measurement Underestimates Ventilatory Volume According to Emphysema Severity

NCT00528944 | Completed

• 1 other identifier: AAAB6328
• Study Type: observational
• Target: 73
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Emphysema

Keywords

alveolar volume; pulmonary function testing; emphysema

Outcome Measures

Primary Outcomes (2)

• Difference between DLCO SB alveolar volume and the total lung volume measurement from plethysmography

  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

  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

Study Arms (3)

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

Eligibility Criteria

• Age: 18 Years - 81 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)
• 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.

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Columbia University: lead

Study Sites (1)

Columbia University Cardiopulmonary, Sleep and Ventilatory Disorders Center

New York, New York, 10032, United States

Location

MeSH Terms

Conditions

Emphysema

Condition Hierarchy (Ancestors)

Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Officials

• Robert C Basner, MD

  Columbia University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: September 11, 2007
• First Posted: September 14, 2007
• Study Start: January 1, 2006
• Primary Completion: July 1, 2008
• Study Completion: July 1, 2008
• Last Updated: July 7, 2015

Record last verified: 2015-07

Locations

US (1)