Methode zur Messung absoluter Intrapleuraldrucke mit dem Ösophagus-Ballonkatheter

The mechanisms of controlling residual volume and lung emptying in different ages have been examined. Elastic bandage was wrapped around the abdomen, chest and shoulder (chest strapping). The measurements of various lung volumes and airway resistance were performed with and without chest strapping. Reduction in all lung volumes including residual volume (-12%) and light increase in airway resistance were obtained in subjects below 25 years with chest strapping, whereas residual volumes were higher (+ 17%, + 12%) under chest strapping in subjects between 35 and 50 years and > 60 years of age, respectively. The airway resistance was also considerably higher in these two groups, A decrease in residual volume points to the fact that the major controlling mechanism of residual volume lies in the chest wall. Chest strapping removes the outward force on the airways, enhances their closure, and traps more air, which increases residual volume. This means that the limitation of emptying lies in the airways in advanced age ( > 34 years)

Section: Methodsmentioning

confidence: 99%

Mechanism of Controlling Residual Volume and Emptying Rate of the Lung in Young and Elderly Healthy Subjects

Islam¹

1980

“…and tracheotomized. According to Weller and Reif [34], in spontaneously breathing animals the airway resistance is proportional to the difference of esophageal pressure (z)Poes) caused by 10 ml tidal volume. A P0(.s was deter mined via an intraesophageal water-filled catheter by a Statham pressure transducer.…”

Section: Methodsmentioning

confidence: 99%

Cyclic Nucleotide Metabolism in Experimental Bronchial Constriction in Rabbits

Kaukel¹,

Lanser²,

Völkel³

et al. 1978

In anesthetized, spontaneously breathing rabbits, intratracheally administered isotonic saline, acetylcholine (Ach) and histamine (His) induced an increase of airway resistance up to 183, 571, and 312%, respectively, compared with untreated controls. This was accompanied by a decrease of the arterial pO₂. Bilateral cervical vagotomy led to nearly complete inhibition of the saline- and Ach-induced bronchoconstriction, whereas the His effect was only reduced to 202%. Vagotomy did not improve the arterial pO₂. While the bronchoconstrictive effects of isotonic saline and Ach revealed a significant linear correlation with the increased cGMP/cAMP ratio, His did not cause an alteration of the cGMP/ cAMP ratio to a degree that corresponds to its bronchoconstrictive activity. These data indicate that (1) bronchoconstriction-inducing agents may act (a) by stimulation of the parasympathetic nerve or (b) by contracting smooth muscles directly; (2) alveolar ventilation is not regulated by the parasympathetic nerve, and (3) bronchoconstriction induced by parasympathetic stimulation is associated with or mediated by an increase of the cGMP/ cAMP ratio

“…The volume of inspired air was measured by integrating inspiratory airflow. Changes in intrathoracic pressure were measured by means of an intra-oesophagcal bal loon catheter | Weller and Reif, 1965).…”

Section: Methodsmentioning

confidence: 99%

Relationship between Pulmonary Embolism, Airway Obstruction and Hypersensitivity of the Airways in Dogs

Islam¹,

Zimmermann²,

Ulmer³

1977