[The function of respiratory muscles in healthy persons during tube breathing]. / Výkon dýchacích svalu u zdravých lidí behem dýchání pridanou trubicí.

BACKGROUND: Tube breathing (added dead space of 600 ml) stimulates ventilation by hypercapnia and is proposed as a new test of respiratory chemosensitivity. In this study the increase of respiratory work during tube breathing was evaluated by two methods. METHODS AND RESULTS: In the first one respiratory values were measured and the rate of respiratory work was calculated according Otis, Crosfill and Widdicombe. In the second one the increase was indicated by changes in oxygen consumption at various levels of ventilation. The control rate of total respiratory work in healthy subjects was 0.07 +/- 0.04 W, during the test it was 0.18 +/- 0.07 W. The control oxygen consumption was e.g. 0.28 +/- 0.09 l.min-1 and during the test 0.32 +/- 0.06 l.min-1. CONCLUSIONS: The increase of work of breathing during the test is relatively small and is related especially to higher minute ventilation. The new test of respiratory chemosensitivity could be therefore accepted even for patients with respiratory disease.

[Does exogenous airflow resistance reduce endogenous airway resistance in healthy persons?]. / Snizuje exogenní proudový odpor endogenní odpor dýchacích cest u zdravého cloveka?

The aim of our investigation was to assess whether a preinserted model resistance of a certain magnitude will expand the airways during inspiration and thus reduce the resistance of the airways conceived as the sum of the value of the endogenous airway resistance without obstruction and the value of the exogenous pre-inserted model resistance. The model resistance and resistance of the airways were assessed by means of a whole-body plethysmograph. The airway resistance was evaluated in 10 healthy men during inspiration and expiration, using a dictated breathing pattern. When a model resistance of 0.75 kPa.l-1.s-1 was preinserted during dictated minute ventilation of 30 l.min-1 and an air current of 1 l.s-1 the value of the airway resistance increased markedly, as compared with the same breathing pattern without obstruction. The resistance increment was, however, by 30% lower than the expected value. At the same time the functional residual lung capacity increased.

[Glomerulonephritis in sarcoidosis]. / Glomerulonephritis bei Sarkoidose.

The renal involvement in sarcoidosis can be demonstrated as nephrocalcinosis, nephrolithiasis, granulomatous nephritis, and glomerulonephritis. The clinical signs of a renal manifestation are inferior than the morphological findings, so that the reported frequency of 9-25% is an approximate value. In the literature the glomerular changes are rare. In the case of glomerulonephritis the membranous form is dominating; an extracapillar-proliferative glomerulonephritis is described in only 3 cases in the literature. The course of a 16-year-old male patient with an extracapillar-proliferative glomerulonephritis and M. Boeck is described in detail. After a prednisolone therapy for 2 years, which was introduced by methylprednisolone at 1000 mg for 3 days, the renal function was improved continuously.

Collection of data in investigations done in the Research Institute's laboratory of the clinical physiology of breathing, and their computerization.

The authors discuss the problem of the need for and utilization of a computer in the research and clinical laboratory, of the Research Institute's department of the clinical physiology of breathing. They report on their own way of an economical use of computers for the collection, storage and evaluation of data. Most important is a uniform approach to the arrangement of data in the databank, which makes it possible, even with a different number and type of data about the patients examined and with different kinds of sets, to use a wide range of statistical, computing, sorting and graphic methods without any modifications and without the development of new programmes.

Fibrocapnography in the control of the respiratory airways passage.

With the authors' method of a fibrobronchoscopic investigation using a translucent catheter in the fibrinoscope Olympus with an operational channel of 1.9 mm there were determined in 8 patients in the sitting position possibilities of estimating the degree of free passage in the respiratory tract. Patients with relapsing bronchial inflammations were examined before and after the aspiration of bronchial secretions that was restricting the passage in the respiratory tract prior to the investigation. The measurement was done with apparatus URAS of the firm Jäger using recorder Hellige . Investigation after the aspiration of the bronchial secretions was supplemented by the inhalation of a highly concentrated O2 in two inspirations. In a well ventilated region there took place even regionally changes in the amplitude of the shape and slope of the end of the expiration curve of the capnographic record. The investigation is non-invasive and technically not very demanding. According to the results obtained in our conditions of investigation a further verification of the validity of the results attained can be recommended; also a modification of the capnographic devices in anaesthesiological apparatus is recommended for possible measurements to be done regionally at the level of the primary bronchi.

Importance of mathematical models and multivariant statistical analysis for the diagnosis of ventilation disorders.

The authors present results of a comprehensive, mostly mathematical, solution of problems of the mechanism of breathing and ventilation. The need for a multivariant approach is based on the knowledge of disorders of the individual factors influencing ventilation. The authors are convinced that this approach means a useful contribution to the establishment of diagnosis and to economization of treatment.

Influence of the speed of expiration on the magnitude of the total resistance (Rt) assessed by means of a whole-body plethysmograph.

The authors demonstrate by comparing results of the mathematical model FMAR 8G and curves recorded during examination by means of a whole-body plethysmograph the influence of the expiration speed on value Rt in patients with an altered elasticity in the alveolar area and with an enhanced collapsibility of the respiratory pathways.

Simulation of human reactions under extreme conditions.

Lung mass determination in cooperative subjects is possible by computation from the "flow-volume" loop, if total lung resistance (Raw) is known. The model is applicable to tracking changes in weightlessness. Modifications for improving the result are discussed.

[Longitudinal control of a selected group of young men in view of chronic bronchitis incidence (author's transl)]. / Longitudinale Beobachtung eines ausgewählten Kollektivs junger Männer im Hinblick auf die chronische Bronchitis.

Report on a prospective longitudinal study of a group fo 16 years old men of Prague, followed up to 6 years. Every two years questionnaires were checked and fluorography, ECG and breathing function tests had been done, too. The group of 341 young men, whose data were complete, had been divided into smokers and nonsmokers, in students and apprentices as well as in healthy persons and people, who suffered from chronic bronchitis. All men with chronic bronchitis had a smoker-history but breathing function tests were normal. First signs of bronchitis will not be recorded by function tests but will be found out by subjective symptoms about 3 years after the beginning of smoking.

The influence of endobronchial fluid on the ventilation.

We evaluated the influence of 2 0ml contrast substance Dionosil aq. on the ventilatory function of lung 21 patients who suffered from relapsing bronchial inflammations. The spirographic examination before the local anaesthesia was accomplished with Vitalograph apparatus, the same examination after local anaesthesia of 3 ml 3% cocaine and 60 mg lidocaine and after the bronchoscopy and bronchography and simultaneously was made the bronchocinematographic recording. We verified that the presence of 20 ml contrast substance decreased significantly the values of VC, FVC, FEV1,0 and FEF25--75 and a little even the values of FEV%. The local anaesthesia of the bronchial three did not influence the ventilation values. The bronchocinematography indicated even in contour bronchographs of great bronchi that the intial lumina of peripheral bronchial branches were dispersely fullfilled with contrast media. Because of small flow speed in his section the contrast substance has stopped and it did not move neither at forced breathing nor at coughing. The ventilation secured probably only minor nonfilled branches. Our discoveries contribute to the clearance of failure causes of inhalatory medical treatment with patients having a mild higher viscosity of bronchial secretions.

The problem of airways collapse during expiration.

In this work there are described two models of breathing mechanics which are aimed to the collapse problem of airways during expiration. The first model (FMAR 7) in the solution respects only the resistance problem of the airways walls against the ambient pressure. The second model (FMAR 8) takes account of the influence of elasticity of alveolar walls. The resultant curves were calculated according to the model (FMAR 8) on the parameter basis obtained by means of patient measuring and these are well comparable with curves noticed during the examinations of objective persons.

[An unhomogeneous model of the respiratory mechanics (author's transl)]. / Nichthomogenes Modell der Atmungsmechanik.

Mechanics of the respiratory system was simulated on analogue computer by a two-compartmental model. Each compartment expresses a functionally (not anatomicall) different part of the lungs, corresponding to some unhomogeneity within the system. The influence of this unhomogeneity on characteristics parameters of the lung (resistance, compliance) was analysed in simulated experiments. This seems to show the way how to express the degree of the lung function disturbance by some quantitative relations.

Results of simulation of non-homogeneous ventilatory mechanics for a patient-computer arrangement.

A model of the ventilatory mechanic system was realised on the MEDA TC 41 analogue computer; it consists of 2 structurally identical compartments, differing in the values of their coefficients. By changing the values of coefficients and the relations between the 2 compartments, it was possible to simulate the non-homogeneity of a real, pathologically-changed system of the body afflicted by disease. Complex resistance loops with phase shifts. identical with those really registered from patients, were realised; this was impossible for models with only 1 compartment. By changing the non-homogeneity of the model., it was possible to simulate the past and future development of the state of the diseased patient with sufficient reliability.