Convective gas mixing, airway dimensions and lung function parameters in patients homo- or heterozygote for hereditary alpha1-antitrypsin deficiency.

Informations about convective gas transport and airway morphometry as a function of volumetric lung depth (V(LD)) can be evaluated by means of two methods based on aerosol inhalation and determination of aerosol pulse parameters (APP) and effective airway dimensions (EAD). APP, EAD and conventional pulmonary function tests (PFT) were measured in patients homo- and heterozygote for alpha1-antitrypsin (alpha1-AT) deficiency. Thirteen homozygote subjects (ZZ allele), 21 heterozygote subjects (MZ allele) and 20 healthy controls were included. Anthropometric data were similar in all groups. APP but not PFT and EAD showed slight significant differences between controls and heterozygotes. However, PFT, APP and EAD from ZZ-homozygotes were strongly different from those of the other groups. Differences were also observed for APP between control smokers and nonsmokers and for APP, PFT and EAD between control nonsmokers and heterozygote smokers but not between heterozygote smokers and heterozygote nonsmokers and control nonsmokers and heterozygote nonsmokers, respectively. The data suggest that lung emphysema causes variations of pulmonary convective gas mixing detectable by measurement of APP which obviously precede variations of PFT. Our data further suggest that heterozygotes are not automatically at risk for the development of lung emphysema. Therefore we also regarded the results with request to individual smoking habits and found an increased risk in heterozygote smokers when compared to control nonsmokers.

Deposition of inspired aerosol particles within the respiratory tract of patients with obstructive lung disease.

Total deposition of monodisperse aerosol particles in the size range between 1 micron and 3 microns was measured in patients with obstructive lung disease and in normal people using equal breathing conditions for both groups. It turns out that for breathing conditions at rest, deposition for patients is higher, especially in the case of 1 micron particle: A second breathing pattern similar to forced exercise, but including a breath holding interval of 6 s after inhalation, is applied to throw some light on the effect of time-dependent deposition mechanisms. The results show less differences between both groups, indicating that enhanced gravitational deposition during respiratory pauses compensates for differences in lung morphometry.

Thirty month variability of aerosol pulse dispersion and conventional lung function parameters in healthy middle aged smokers and nonsmokers.

Chronic cigarette consumption is a generally accepted reason for the development of chronic obstructive pulmonary disease (COPD). COPD correlates to histomorphological parameters of lung structure as well as pulmonary function tests (PFT). COPD related changes affect PFT determined by conventional methods (bodyplethysmography, spirometry) as well as parameters of convective gas mixing. This study evaluates the diagnostic potential of a non-invasive aerosol method for the discrimination between healthy smokers and nonsmokers in comparison to conventional PFT. The aerosol method is based on the inhalation of small aerosol pulses suspended in particle free air and determines their changes during the breathing maneuver. Changes of aerosol pulse parameters (APP) are used to describe the convective component of gas mixing during ventilation. PFT and APP were determined in 40 healthy subjects (nonsmoker: 51.1 +/- 1.5 years; smoker: 49.6 +/- 1.5 years, 39.1 +/- 2.2 pack years) before and after a time interval of 30 months. Conventional PFT in smokers and nonsmokers showed no relevant differences between the values at the beginning and the end of the observation period. Thirty months later, at the end of the observation interval, a very similar behavior of the APP was obtained, which strongly confirmed the prior observed differences between smokers and nonsmokers. The data suggest that cigarette smoke-induced variations of lung function are also detectable in clinically asymptomatic smokers. Even in cases of normal PFT, most APP are able to discriminate between healthy smokers and nonsmokers. Since PFT showed only minor differences between both groups, it is indicated that APP are superior to PFT in the detection of early disturbances of lung ventilation in healthy smokers. Mean values of PFT and APP in smokers and nonsmokers showed a high reproducibility of the data obtained at the beginning of the study as well as at the end of the observation period. The data of our study further confirm that parameters of pulmonary gas exchange and gas mixing are affected by cigarette smoke at an earlier time than parameters of breathing mechanics.

Experimental data for total deposition in the respiratory tract of children.

Up to now only few experimental data for total deposition of inhaled aerosol particles are available for children. In this study 29 healthy children aged between 3 and 14 years volunteered for the determination of 1 micron, 2 microns and 3 microns particles for spontaneous and controlled breathing. It turns out that total deposition values for children are higher than for adults. The effect is significant for all particle sizes (Kruskal-Wallis). For the applied breathing patterns deposition decreases as a function of body height. For inhalation risk assessments the number of particles deposited per unit time (deposition rate) rather than the deposition per breath has to be taken. During spontaneous breathing at rest the deposition rate is on average higher for children than for adults.

[Long-term effect of the beta 2-sympathomimetic formoterol in young smokers--study of duration and site of effect of bronchodilatation using conventional methods of lung function and monodispersed aerosols]. / Langzeitwirkung des beta 2-Sympathomimetikums Formoterol bei jungen Rauchern--Untersuchung von Wirkdauer und Wirkort der Bronchodilatation mittels konventioneller Lungenfunktionsmethoden und monodisperser Modellaerosole.

Formoterol is a novel selective beta 2-sympathomimetic inducing bronchodilatation after inhalation or oral application. Compared to other beta 2-sympathicomimetics the substance begins to act very rapidly even at a much lower dosage level, while it remains effective for at least 12 hours. In the present study the bronchodilatory effect of 24 micrograms MDI formoterol was investigated in 18 healthy smokers between 20 and 30 years of age means. Measurement was effected by means of conventional lung function diagnostics (body plethysmography, spirometry) and an biophysical aerosol measurement method for determining the effective airways dimensions (EAD). This method is based on the gravitational losses of a previously inspired monodisperse model aerosol during apnoea periods of different duration. It enables determination of the EAD as a function of the volumetric lung depth (VLT). A marked and universally measurable bronchodilatation is detectable directly after formoterol has been inhaled. The longterm action of formoterol was confirmed for more than 15 hours after application, using the conventional lung function test and the EAD method. Over and above this the EAD determination showed that the bronchodilatory effect was much more marked in the central airways than in the periphery of the lungs, thus confirming the effect generally described for beta 2-sympathomimetics as being mainly directed towards the central airways region.