Table. 5—

Summary of within- and between-manoeuvre acceptability criteria

Within-manoeuvre criteria
 Individual spirograms are “acceptable” if
  They are free from artefacts 3
   Cough during the first second of exhalation
   Glottis closure that influences the measurement
   Early termination or cut-off
   Effort that is not maximal throughout
   Leak
   Obstructed mouthpiece
  They have good starts
   Extrapolated volume <5% of FVC or 0.15 L, whichever is greater
  They show satisfactory exhalation
   Duration of ≥6 s (3 s for children) or a plateau in the volume–time curve or
    If the subject cannot or should not continue to exhale
Between-manoeuvre criteria
 After three acceptable spirograms have been obtained, apply the following tests
  The two largest values of FVC must be within 0.150 L of each other
  The two largest values of FEV1 must be within 0.150 L of each other
 If both of these criteria are met, the test session may be concluded
 If both of these criteria are not met, continue testing until
  Both of the criteria are met with analysis of additional acceptable spirograms or
  A total of eight tests have been performed (optional) or
  The patient/subject cannot or should not continue
 Save, as a minimum, the three satisfactory manoeuvres
  • FVC: forced vital capacity; FEV1: forced expiratory volume in one second.