Revision C CASE B-17
2060290-201
Miscellaneous: Spirometry Reference Value Equations, Interpretation Modes, Measurements
Curve typical of restriction
Expiratory stenoses
* If all four interpretation criteria are normal, the interpretative
statement Normal lung function values is displayed.
Possible causes reduced lung volume (restriction), elevated pulmonary
elasticity (fibrosis)
Criterion FVC Act. < xx % FVC Ref. and (VC MAX/(2 x MEF50) < 0.8)
Definition Interpretative Statement
> 70 % normal*
50 ... 70 % curve typical of mild restriction
< 49 % curve typical of moderate to severe restriction
if < 70 % further lung function measurement recommended
Possible causes Stenoses in the large airways, extrathoracic flow obstruction,
expiratory tracheal stenosis
Criterion FVC Act./PEF > 0.8
Definition Interpretative Statement
< 0,8 normal*
> 0,8 Further examination for extrathoracic flow obstruction and
expiratory tracheal stenosis recommended. Watch patient
cooperation.