Disturbed Blood Flow Induces Endothelial Dysfunction in Severe Chronic Obstructive Pulmonary Disease

Study Overview
=================
Brief Summary
-----------------
The aim of the study is to determine if increased retrograde shear would further deteriorate the already impaired vascular function in severe COPD patients.

Official Title
-----------------
Disturbed Blood Flow Induces Endothelial Dysfunction in Severe Chronic Obstructive Pulmonary Disease

Conditions
-----------------
Chronic Obstructive Pulmonary Disease

Intervention / Treatment
-----------------
* Other: retrograde flow
* Other: oxygen


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: COPD chronic hypoxemia Exclusion Criteria: an acute exacerbation, active respiratory infection or infection of other localisation 6 weeks prior to the visit relevant coexisting lung disease such as interstitial lung disease, cancer, renal failure, thromboembolic disease or major cardiovascular event during the previous year informed consent not provided or inability to comply with the study protocol

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Basic Science
Allocation: Non-Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: control subjects-retrograde flow<br>Retrograde flow was induced in control subjects. | Other: retrograde flow<br>* Two pneumatic cuffs were placed on the experimental arm, one on the lower forearm, and the other on the upper arm. Two cuffs were simultaneously inflated for 20 minutes. The distal cuff was inflated to 75 mm Hg and the proximal cuff was inflated to 40 mm Hg. The contralateral (control) arm was cuff free during this intervention.<br>|
| No Intervention: control subjects-control<br> | |
| Experimental: hypoxemic COPD-retrograde flow<br>Retrograde flow was induced in hypoxemic COPD patients. | Other: retrograde flow<br>* Two pneumatic cuffs were placed on the experimental arm, one on the lower forearm, and the other on the upper arm. Two cuffs were simultaneously inflated for 20 minutes. The distal cuff was inflated to 75 mm Hg and the proximal cuff was inflated to 40 mm Hg. The contralateral (control) arm was cuff free during this intervention.<br>|
| No Intervention: hypoxemic COPD-control<br> | |
| Experimental: normoxemic COPD-retrograde flow with oxygen<br>Retrograde flow was induced in COPD patients with normalized arterial oxygen saturation. | Other: retrograde flow<br>* Two pneumatic cuffs were placed on the experimental arm, one on the lower forearm, and the other on the upper arm. Two cuffs were simultaneously inflated for 20 minutes. The distal cuff was inflated to 75 mm Hg and the proximal cuff was inflated to 40 mm Hg. The contralateral (control) arm was cuff free during this intervention.<br>Other: oxygen<br>* Supplemental 100% oxygen administered through a nasal cannula.<br>|
| Experimental: normoxemic COPD-control with oxygen<br>COPD patients with normalized arterial oxygen saturation. | Other: oxygen<br>* Supplemental 100% oxygen administered through a nasal cannula.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change from Baseline Brachial Artery Diameter at 10, 20 and 25 minutes |  | 0,10, 20 and 25 minutes | 
| Change from Baseline Microparticle Count at 20 minutes |  | 0 and 20 minutes |