[Lung function measurements with portable spirometers in children].

In the majority of patients with respiratory disease, the most important diagnostic information can be obtained just by taking a thorough medical history and appraising the general clinical status. Lung function is a valuable tool in routine practice for assessing the general status at the beginning of treatment, for evaluating the clinical course and for documenting the response to therapy. The parameters measured by spirometry are read as volume (liter) or volume per unit of time (flow). If a spirometer is used in pediatrics, its measurements should be linear, within the range of the flow rates achieved by children. Spirometry does not provide information about the respiratory status in the resting state. If pulmonary overinflation or restriction is suspected (for example in patients with cystic fibrosis), a whole-body plethysmograph must be performed in addition to spirometry. Because their cooperation is required, children under the age of 5-6 cannot be given spirometric examinations. The younger the subject, the more important it is that the examiner has experience in dealing with children as well as experience in interpreting lung function readings. By far, not all children have the physical or pulmonary development required to understand how to exhale deeply or forcibly enough. As soon as they start breathing consciously, they will tend to breath flatter and quicker. Therefore, it is worth while for the examining physician to perform the breathing maneuver several times himself in front of the child to show them how it is done and have them practice before the measurement. It is imperative that a curve of the dynamics of the resulting time/flow volume be made available. The curve configuration enables diagnosis and allows assessment of the patient's cooperation. The readings are then used for quantifying analysis.