[Reference values of respiratory parameters in adults 4th paper: reference values for screening parameters of lung...

Reference values for screening parameters, evaluating the shape of flow-volume-curves on forced expiration, were calculated from measurements in 1127 healthy subjects aged between 13 and 72 years. The following parameters were determined by means of the electronic spirometer pneumo-test: 1. the peak flow value Vmax, 2. the whole time constant tauges of the flow volume diagram and its components tau1 and tau2 from the upper and the lower part of the flow volume curve, 3. the most frequent time constant taumax in the distribution function of time constants. In relation to age Vmax-values show a maximum at 35 years and a significant decrease in younger and older subjects. Values in women are significant smaller than in men throughout the range of age. The time constants tauges and tau1 decrease significantly with increase in age. Differences between females and males are not statistically significant for these parameters. The time constants tau2 and taumax are age-independent. Their mean values are identical in all age decades and in women significantly smaller than in man.