Effects of Altitude on Single-Breath Diffusing Capacity for Carbon Monoxide

Effects of Altitude on Single-Breath Diffusing Capacity for Carbon Monoxide in Normal Subjects and Chronic Obstructive Pulmonary Disease

Status

Completed

Phases

Unknown

Study type

Observational

Source

ClinicalTrials.gov

Registry ID

NCT03235297

Acronym

DLCO

Enrollment

Registered

2017-08-01

Start date

2017-08-10

Completion date

2019-07-01

Last updated

2020-02-12

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

COPD

Keywords

Altitude, Diffusing capacity for carbon monoxide, COPD, Pulmonary function testing

Brief summary

The purpose of this study is to further understand the effects of altitude on the physiology of gas exchange in the pulmonary microcirculation in normal subjects and in people with chronic obstructive pulmonary disease (COPD) measured as the single-breath diffusing capacity for carbon monoxide (DLCOsb). The study will determine a mathematical formula to allow for altitude corrections in both study populations to be used clinically in pulmonary labs.

Detailed description

The DLCOsb is one of the most common and widely tests clinically used across the world in pulmonary function laboratories to assess gas exchange from the lung to hemoglobin in the pulmonary circulation. This test is used in the differential diagnosis of respiratory related symptoms, to grade the degree of severity in lung disease, and to objectively monitor the progression of disease or the response to therapies. Therefore, it is important to have standard methods of performing and interpreting this test.This is a prospective study, collecting data from subjects at different simulated altitudes. The study hypothesis is that increasing altitude will increase the DLCOsb in a predictable manner that will allow for mathematical corrections to be applied for uniform interpretation in pulmonary labs at differing altitudes.

Interventions

None listed

Study design

Observational model

COHORT

Time perspective

PROSPECTIVE

Eligibility

Sex/Gender

ALL

Age

20 Years to 80 Years

Inclusion criteria

* Ages 20- 80 years * Subjects must be either healthy or have been diagnosed with COPD

Exclusion criteria

* Anemia (hemoglobin \< 10.0 g/dL) * Carboxyhemoglobin \> 3% * Active smoking * Heart disease or heart failure * Pulmonary hypertension * COPD exacerbation * Pneumothroax within 6 months * Bullous emphysema on chest imaging (Chest X-ray or CT) * Supplemental oxygen use * Diabetes mellitus * Alcohol dependence * Non-English speaking

Design outcomes

Primary

Measure	Time frame
Effect of altitude on measured diffusing capacity for carbon monoxide	3 weeks

Secondary

Measure	Time frame
Comparison of a novel inert gas technique for measuring alveolar volume with body plethysmography	4 months

Countries

United States

Outcome results