1. Look at the Flow-Volume Loop. The peak flow should be attained within the first 200ml.Click here to see examples of #1 "back extrapolation".
2. Look at the Flow-Volume Loop. The peak on the expiratory side should be sharp.Click here to see an example of #2
3. Look at the FEV1 value in the text section. Now Look at the Flow-Volume Loop. There should be no significant decrease then increase in flow before the FEV1 volume (cough or airway closure in the first second).Click here to see an example of #3
4. Look at the Volume-Time curve. It should plateau (but not suddenly) at it's maximum volume (the exhalation should have been as long as possible).Click here to see an example of #4
5. Look at the Flow-Volume Loop. The inspiration should come back to about the same starting point.Click here to see an example of #5
6. Be sure spirometry was done more than 2 times and the results were consistant (best 2 FEV1's are within 200 ml. of each other) (best 2 FVC's are within 200 ml. of each other).Click here to see an example of #6