摘要:

In anesthetized dogs artificially ventilated at constant volume and frequency pulmonary gas exchange and circulatory parameters were measured under alternating conditions of closed and open chest.All parameters of pulmonary gas exchange were the same with closed and open chest when the mean transpulmonary pressure (or lung inflation) was identical. Reduction of the mean transpulmonary pressure with open chest increased the venous admixture and alveolar dead space ventilation.Cardiac output was similar with open and closed chest when the mean intrapulmonary pressure was the same in both conditions. Increase of the mean intrapulmonary pressure up to normal inflation of the lungs under open chest conditions caused a reduction of cardiac output and stroke volume.With open chest an optimum O2 transport rate to the body is achieved when the lungs are subnormally inflated.

ISSN:0025-7931    

DOI:10.1159/000192666

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

Es wird das Untersuchungsverfahren der gleichzeitigen Verteilungsanalyse von Ventilation, Perfusion und O2-Diffusionskapazität in der menschlichen Lunge nach Thews und Vogel beschrieben. Das Verfahren beruht auf dem plötzlichen Wechsel dreier in ihren Diffusionseigenschaften unterschiedener Inspirationsgase und der fortlaufenden Registrierung der alveolären Einmischvorgänge. Neben dem Ventilations-Perfusions-Verhältnis VA/Q und dem O2-Diffusionskapazitäts-Perfusions-Verhältnis DL/Q lassen sich verteilungsbedingte Anteile der alveolo-arteriellen Differenz AaD berechnen. Damit ist das Inhomogenitätsverhalten der menschlichen Lunge vollständig zu beschreiben. Durch apparative Änderungen gegenüber dem von Thews und Vogel angegebe-nen Untersuchungsgang konnte das Verfahren weiter vereinfacht und verbessert werden. Es wurden folgende Änderungen vorgenommen: Eine fahr- und fixierbare Halterung, die die Douglas-Säcke sowie das Dreiwegehahn-Atemventil-System trägt, erlaubt eine rasche Versuchsvorbereitung und -durchführung. Sie ermöglicht die Untersuchung in der für den Patienten günstigsten Lage. Der zusätzliche apparative Totraum wurde wesentlich verkleinert. Die Analyse der exspiratorischen Atemgase erfolgt durch ein Massenspektrometer. Die modifizierte Versuchsanordnung hat sich bisher bei 35 Untersuchungen an 27 teilweise schwer dyspnoischen

ISSN:0025-7931    

DOI:10.1159/000192667

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

1. Das Hauptsymptom der multiplen Lungengefässobstruktion, gleich welcher Genese, ist die Anstrengungsdyspnoe, die sich mit einer erheblich gesteigerten Atemarbeit an den Lungen wegen alveolärer Hyperventilation und Totraumhyperventilation bei verminderter Lungendehnbarkeit und leicht erhöhten viskösen Atemwiderständen objektivieren lässt.Zwischen der Erhöhung des Lungengefässwiderstandes und der Abnahme des Herzzeit- und -schlagvolumens, der Häufigkeit leichter bis mittelschwerer arterieller Hypoxämien sowie der Abnahme des Atemgrenzwertes besteht eine quantitative Beziehung.Die Senkung des arteriellen PCO2, die Vergrösserung des Totraumquotienten und die Abnahme der dynamischen Lungencompliance zeigen keine sichere quantitative Korrelation mit der Schwere der Lungengefässobstruktion.Der teilweise bis vollständige Gefässverschluss bei Embolien in die grösseren Äste der A.pulmonalis und die mehr oder weni

ISSN:0025-7931    

DOI:10.1159/000192668

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

The understanding of pulmonary function immediately after birth and in the weeks following is greatly facilitated if we know the morphological changes accompanying development. As such studies are not easily done on human infants we have performed a number of experimental studies on animals, particularly on the rat. We found by using electron microscopy and morphometric techniques that the gas exchange surfaces and the blood volume increase in such a way as to form a functional apparatus with a diffusing capacity which is proportional to body weight. Hence, the supply of O2 is adequate all through development inspite of drastic transformations of lung structure. In a very recent study we have found that the partial pressure of O2 in the ambient air influences lung growth in the sense that chronic hypoxia leads to a larger gas exchange apparatus, hyperoxia to a smaller one. Lung growth is hence partly dependent on environmental conditions. One of the essential functions of the alveolar epithelium is to provide the alveolar surface with a surfactant coating which reduces surface tension and assures open alveoli: We have recently succeeded in demonstrating this coat as a structural feature by special preparation techniques. The extrapolation of these insights obtained on experimental animals to the human lung is possible on the basis of comparative studies on the morphometry of mammalian lungs.

ISSN:0025-7931    

DOI:10.1159/000192716

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

Since the introduction of intermittent positive pressure ventilation (IPPV) into the treatment of hyaline membrane disease a chronic pulmonary process has been observed leading either to death after months or even years, or to recovery with severe pulmonary residua. The process involves the bronchi as well as the pulmonary parenchyma and is associated with pulmonary hypertension. Understanding of the pathogenesis of this disease is of practical importance. Is it a natural evolution of severe and hitherto early lethal hyaline membrane disease? Present observations rather suggest, that oxygen toxicity, endotracheal intubation and IPPV are the main aetiological factors.

ISSN:0025-7931    

DOI:10.1159/000192717

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

The lung is only partially formed at the time of birth and considerable structural changes take place during childhood, the most important of which appears to be a 6-8 fold increase in the number of alveoli. The process by which new alveoli are developed, i.e. compoundment of septa, segmentation of primary alveoli and alveolisation of respiratory ducts, will be discussed, and their implications related to the probable effects of chronic and s ub-acute diseases of the lung during infancy. The lecture will include photographs of the alveolar patterns of lungs at different ages and in particular photographs of elastic stains showing alveolar ‘nets’. Photographs of acute and sub-acute lung infections in children will be brought along and used either during this session or as part of discussion of other pap

ISSN:0025-7931    

DOI:10.1159/000192718

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

The authors present an account of the preoperative cardiopulmonary examination and on postoperative changes in 77 patients with bronchogenic cancer subjected to radical surgical treatment. Twenty-three of them were older than 65 years. The results of ventilation tests do not differ significantly from those in younger patients; the older patients show only a tendency to higher residual volume and a less favourable ratio between alveolar and total ventilation than younger individuals. In the blood gases and hemodynamic values no significant differences were revealed. The mortality during the initial postoperative period and within six months after operation is not higher in patients over 65 years that in the other groups. The postoperative changes are approximately equal in all age groups. In the older patients only the mean pressure in the right atrium and in pulmonary artery as well as the total pulmonary resistance rise more than in younger cases. No case of respiratory acidosis or right heart failure was recorded.The authors conclude that the age of the patients is not decisive for the indication of radical surgical therapy of bronchogenic cancer and only the preoperative assessement of cardiopulmonary function is important, whereby in older age groups an approximately equal development of postoperative functional changes as in younger groups may be expected.Relative contraindications of more extensive lung resections for bronchogenic cancer include also the advanced age of the patients. The conception of advanced age is, however, usually not specified; the majority of authors agree that the decisive criterion for surgical therapy is the cardiopulmonary function and not advanced age alone. Nevertheless, many authors are rather reserved concerning indication in patients 60-70 years of age.

ISSN:0025-7931    

DOI:10.1159/000192669

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

Simultaneous measurements of oesophageal pressure and respiratory tidal volume were made in fifteen patients with chronic obstructive bronchitis during periods of air and oxygen breathing under dynamic and static conditions. Pressure-volume diagrams were constructed and the total work of breathing in ventilating the lungs was calculated. A decrease in the work of breathing occurred during oxygen breathing in ten of the patients, and an increase was found in the remaining five patients. Values of static lung compliance were obtained in nine of the patients and the values showed no significant change during oxygen breathing. It is concluded that the decrease in the work of breathing during oxygen breathing was probably due to a decrease in airways resistance and this may contribute to the altered sensation of breathlessness found by some patients during oxygen inhalation.

ISSN:0025-7931    

DOI:10.1159/000192670

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

In older infants and preschool children lung function tests can only be performed if the annoyance of the child is of such a short duration that test material can be taken before important changes in respiration take place, or if, the child is bothered in such a small extent that permits them to sleep during the investigation. – These conditions can be realized only for some of the available tests. CO2 analysis in ventilated air performed by infrared method allows a judgement of changes in ventilation. Microgasanalysis in the arterialized cutaneous blood during breathing room air or 40% O2 to some extent permits the differentiation of arterial hypoxemi

ISSN:0025-7931    

DOI:10.1159/000192720

出版商:S. Karger AG    

年代:1970

数据来源: Karger

摘要:

In the anesthetized intact dog, the intravenous injection of caffeine (10 or 20 mg/kg) caused the following changes: (a) decrease in pulmonary resistance; (b) increase in pulmonary compliance; (c) increase in heart rate; and (d) decrease in blood pressure. In the heart-lung preparation, caffeine induced the first three changes: (a) probably by a direct action on the bronchial smooth muscle; item (b) was related to the decrease in pulmonary vascular resistance; and item (c) was accompanied by an increase in myocardial contractility in the heart-lung preparation. There was no evidence to support the theory that caffeine potentiates the effects of epinephrine on the heart and the lung.

ISSN:0025-7931    

DOI:10.1159/000192671

出版商:S. Karger AG    

年代:1970

数据来源: Karger