Parameter | Favorable | Less favorable |
Clinical | Age ≤60 years | Age >60 years |
Progressive dyspnea despite maximal medical therapy | Comorbid illness (eg, coronary heart disease, heart failure)* |
Ex-smoker | Current smoker |
Physiological | FEV1 ≥40 percent predicted | FEV1 <40 percent predicted |
Hyperinflation (eg, TLC >100 percent predicted, RV >150 percent predicted) | Absence of hyperinflation |
| DLCO <40 percent predicted |
PaCO2 >45 mmHg |
Pulmonary hypertension (eg, elevated TRV and estimated PA systolic pressure; mean PA pressure >20 mmHg) |
Unable to participate in pulmonary rehabilitation |
Imaging | CXR: bulla ≥30 percent of hemithorax in a symptomatic patient | CXR: poorly defined bulla(e) |
HRCT: large and localized bulla with compressed parenchyma and vascular crowding adjacent to the bulla | HRCT: homogeneous, diffuse emphysema without a single large bulla |
Isotope scan: well-localized matching defect with normal uptake and washout for the rest of the lung¶ | Isotope scan: absence of target zones, poor washout in rest of the lung¶ |