Table 2.

Screening and eligibility procedures

1.	Patient referred to study physician
2.	Patient consent obtained
3.	Screening Assessment 1: medical history, supplemental oxygen use and physical exam
4.	Determine if patient meets eligibility criteria
5.	Screening Assessment 2: electrocardiogram, spirometry, plethysmography, DLco, 6 MWT, Computed Tomography Scan, PaO2, PaCO2, arterial saturation, continine level, alpha-1 antitrypsin concentration
6.	Determine if patient continues to meet eligibility criteria
7.	Patient enters and completes pulmonary rehabilitation program
8.	Baseline measurements taken: medications, supplemental oxygen use, physical exam, electrocardiogram, spirometry, plethysmography, DLco, 6 MWT, cycle ergometry, quality of life surveys, chest x-ray, ventilation/perfusion (V/Q) scan, PaO2, PaCO2, arterial saturation, blood electrolytes, liver profile, renal profile, CBC, pregnancy test (where appropriate), and continine level
9.	Final determination of patient eligibility
10.	Randomization to Control or Treatment arm of the VENT study.

Abbreviations: DLco = diffusion of the lung for carbon monoxide, 6 MWT = six minute walk test, PaO₂ = arterial pressure of oxygen, PaCO₂ = arterial pressure of carbon dioxide, CBC = complete blood count.