| Spirometric findings |
|
|
| FEV1 |
�?< 80% of the predicted value or the LLN |
Normal or �? |
| FEV1/FVC |
�?(because �?in FEV1 > �?in FVC) |
Normal or �?(because �?in FEV1 is proportional to �?in FVC) |
| VC |
�?< 80% of the predicted value or the LLN |
�? |
| Flow-volume loop |
Air trapping: scalloping of the expiratory limb; seen in conditions such as emphysema and in patients who have undergone a pneumectomy |
Narrow flow-volume loop |
| Plethysmograph findings |
|
|
| RV |
�?�?120% of the predicted value or the ULN |
Normal or �? |
| FRC |
�? |
�? |
| TLC |
Normal or �? |
�? |
| Airway resistance |
�? |
Normal |
| Lung compliance |
Normal |
Normal (extrinsic causes) or �?(intrinsic causes) |
| DLCO |
Variable (e.g., �?in emphysema, �?or normal in bronchial asthma, normal in chronic bronchitis) |
Variable (e.g., normal with extrinsic causes, �?with intrinsic causes) |
