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Biomedical subjects

M Englert

Publications and source records attributed to M Englert.

At least 19 recordsLinked to original sources
PubMed1978

Evolution of intrathoracic airway mechanics during lung growth.

Elastic recoil pressure of the lungs (Pst(L)), maximum expiratory flow rates (MEF), critical transmural pressure of the collapsible flow-limiting segment (Ptm'), and S-segment conductance (Gs) have been determined in 40 healthy subjects, 7-18 yr old. Pst(L), measured at different lung volumes (fractional) from the expiratory quasi-static pressure-volume curves, increases progressively with age. MEF's, at different lung volumes, are closely related to total lung capacity (TLC); the ratios MEF/TLC, at all lung volumes, are independent of age. Ptm' is also independence of age and body height, most values lying between 0 and -15 cmH2O; this finding suggests that the locus and the behavior of the collapsible segment do not change during growth. Gs, in absolute value, increases with growth but, when adjusted for lung size, Gs decreases steadily with age and body height. These relations suggest that, from childhood to adolescence, the air spaces grow disproportionately more than the airway system.

Adolescent↗
PubMed1978

Impairment of pulmonary function in acute pancreatitis.

Arterial blood gas levels, lung volumes, and diffusing properties for carbon monoxide were measured in 22 patients with uncomplicated acute pancreatitis who had no clinical or radiographic evidence of pulmonary involvement. Mild arterial hypoxemia (less than 75 mm Hg) was present in four patients. The mean values of inspiratory lung volumes were clearly reduced, and the diffusing properties were sharply altered; the mean value for the diffusing capacity of carbon monoxide per unit of lung volume (Krogh's constant [KCO]) was 78 percent of predicted. Four patients with a low KCO in the first four days after an acute episode had normal values when reevaluated one week later. These findings suggest the occurrence, even in mild acute pancreatitis, of transient pulmonary injury mainly localized at the level of the capillaries, leading to decreased gas transfer.

Acute Disease↗
PubMed1977

[Supervision of patients with artificial heart valves (author's transl)].

Valvulotomy mortality is 2--5% depending on the age and the condition of the myocardium. Ball valves, disk valves and biological prostheses are most commonly used. The most important complications of valve prostheses include bacterial endocarditis, loosening of the artificial valve, hemolytic anemias and thromboembolism. Presently, the Hancock prosthesis gives the best results. Thrombus formation, the most frequent complication of ball and disk valves--sometimes in spite of anticoagulation--does not occur with the biological prosthesis. Strict anticoagulant therapy and supervision is therefore not necessary. Should the Hancock prosthesis continue to prove satisfactory, it is to be hoped that resistance to early operation will be overcome and that the most important cause of failure, valvulotomy in an irreversible damaged heart, will thus be eliminated.

Anemia, Hemolytic↗
PubMed1977

An automatic device for single-breath CO diffusing capacity in dogs.

We describe a very simply operated system by which single-breath CO diffusing capacity (DLCO) can be measured in anesthetized dogs. All controls and the automatic system are operated pneumatically. Cams forming an integral part of the pistons of the inspiratory and expiratory syringes activate push buttons which control the valves, enabling dead spaces to be flushed, a specific volume of air to be injected into the dog's lungs, and expiratory samples to be taken. Our results, due account being taken of the dogs' weight, are in the upper range of normal values published in earlier studies; the reproducibility of the method is good.

Animals↗
PubMed1977

Lung hypoplasia in congenital pulmonary valve stenosis.

The pulmonary function of ten adult patients with congenital pulmonary valvular stenosis was investigated. The patients clearly showed smaller lungs than healthy control subjects of equivalent age and height; lung elastic recoil pressure was normal at any given percentage of measured total lung capacity, indicating that postnatal parenchymal damage is not the cause of the small lungs. The lung diffusing capacity for carbon monoxide was reduced, reflecting the anatomical alterations of the pulmonary vascular bed. Finally, the maximal flow-static recoil curves showed a fixed (not dynamic) reduction of airway dimensions: the critical transmural pressure in the collapsible flow-limiting segment (Ptm') was normal, but the conductance of the S segment was lowered. These abnormalities most likely reflect inadequate development of the lung and suggest that pulmonary blood pressure may be an important determinant of lung growth in the postnatal period.

Adolescent↗
PubMed1977

Mechanics of breathing in patients with atrial septal defect.

Mechanics of breathing and pulmonary diffusing properties were investigated in 24 adult patients with atrial septal defect. The patients were divided into 3 groups according to mean pulmonary artery pressure: less than 19 mm Hg (group I), 20 to 24 mm Hg (group II), and greater than 25 mm Hg (group III). The only change observed in group I was a marked increase in diffusing capacity. Patients of group II showed not only an increase in diffusing capacity, but also an overt decrease in maximal expiratory flow at all lung volumes and at any given driving pressure. For these two groups, a highly significant inverse correlation was found between changes in diffusing and elastic lung properties (r = -0.71; P less than 0.001). In patients of group III, the expiratory flow remained clearly decreased; furthermore, lung compliance and lung volumes were sharply reduced, airway resistance was elevated, and diffusing capacity was normal. Finally, from group I to group III, the lung elastic recoil became progressively diminished at small lung volumes. These results suggest that an increased pulmonary blood volume induces an increase in diffusing capacity and a slight decrease in lung compliance. Simultaneous existance of high intravascular pressure strengthens the effects of increased pulmonary blood volume on lung mechanics and results in significant abnormalities in the lung mechanical behavior. It is postulated that these effects are due to a competition for space between vessels and airways within the bronchovascular sheaths, with a subsequent compression of small airways.

Adult↗
PubMed1976

Static mechanical lung properties in healthy children.

The elastic properties of the lung (elastic recoil and static compliance) have been studied in 27 children from 7 to 15 years of age by a quasi-static method. There is a significant relationship between the static expiratory compliance and the quasistatic pressures at different percentages of total lung capacity on the one hand, and height and age on the other. The specific compliance is independent of both height and age. The authors also use a sigmoid mathematical model based on the relationship between specific compliance and maximum pulmonary volume. This model fits well with the experimental data. Comparison is made with the currently used exponential model of Salazar & Knowles. The results favour the hypothesis of an increase in the number of alveoli all through childhood.

Adolescent↗
PubMed1975

A sigmoid model of the static volume-pressure curve of human lung.

The authors present a sigmoid mathematical model of the pressure-volume curve of the human lung, based on a relationship between the specific compliance and the maximal pulmonary volume: (see article). This model fits better the experimental data obtained in 20 young normal adults than the currently used exponential model of Salazar and Knowles (1964). The independence between the constant K' and body height is interpreted as a constancy of pulmonary structure for normal subjects of the same age range.

Adult↗