Airway Obstructions: Clinical and physiological aspects

Abstract

Some problems connected with obstructions in the larynx, trachea and bronchi are discussed. These widen during inspirium and narrow during expirium. This provides a simple explanation of expiratory difficulties in cases of partial obstructions in the finer bronchi. The inspiratory stridor is generally explained in an analogous way on the assumption of a valve mechanism through a sucking together of swollen soft parts. In experimental stenosis the rate of flow is very little affected during the active inspiration. The expiration is prolonged, and the rate of flow sinks here with increasing stenosis. The stenotic sound is therefore most pronounced during inspiration even without any valve mechanism. Airway obstructions may increase the respiratory work markedly. The first sign of unsatisfactory ventilation is increased CO₂-tension in the arterial blood. This can now be determined in capillary blood and is of great clinical value. In desperate cases respirator treatment may save the patient's life.