Administering the spirometric test
It is essential for a proper measurement of the VC and the FEV1 that the patient delivers a maximum performance. On that account the patient needs to be properly instructed prior to the test, and needs to be continuously and loudly encouraged while performing the maneuvers. Unprofessionally performed tests lead to artificially low values of VC and the FEV1, and may give rise to erroneous interpretations. In inexperienced patients each part of the protocol needs to be properly demonstrated, and the patient should be familiarized with the instructions. The tests should be performed in a suitable, quiet environment.
Pay attention to the following points:
- how does the patient perform the maneuvers
- are they delivered with maximal effort, and with a 'blast' at the start
- are the maneuvers delivered without hesitation
- does leakage occur at the mouthpiece
- does the maneuver end prematurely