[Experiences with the use of oscillating high frequency ventilation].

Our investigations have demonstrated that the effect of oscillatory high-frequency ventilation (HFO) on gas exchange in dogs is directly proportional to the oscillatory flow amplitude VM. Because of the equation: VM = PM/Z, gas exchange is increasing with rising oscillatory amplitude of the ventilation pressure PM and decreasing with rising impedance Z of the respiratory system. This system consists of endotracheal tube and the lungs of the dog investigated.

The influence of hypoxia and hyperoxia during metabolic acidosis and alkalosis on pulmonary haemodynamics.

In anaesthetised, mechanically ventilated Beagle dogs a moderate metabolic acidosis increased the pulmonary vascular resistance to a greater extent than moderate hypoxia. Alkalosis and hyperoxia did not alter the pulmonary vascular tone.

[Equipment combination for the use of normal frequency and high frequency jet ventilation].

Over the last eight years high-frequency ventilation has been extensively evaluated both in the clinical and laboratory settings. Two types of jet ventilators for application of normofrequency and high-frequency jet ventilation have been developed. A combined equipment is described with gas mixer, heater-humidifier, monitoring, membrane solenoid valve and a special injection system.

[Use of high frequency ventilation in patients with respiratory insufficiency].

High frequency ventilation is very common today for treatment of patients with respiratory insufficiency in the ICU as well as intraoperatively. This special kind of artificial ventilation is suitable for patients with decreased lung volume and reduced thoracic and lung compliance. Favourable results in the treatment of ARDS are described.

[Animal experiment studies of morphologic changes in the trachea and lung in high frequency ventilation].

Prolonged high frequency ventilation (24 hrs) in dogs leads to morphological changes in the trachea as well as in the bronchi. Erosive changes of tracheal epithelium were observed whereas small bronchi and bronchioli exhibited luminal obstructions by mucus plugs, caused by hypersecretion of goblet cells. Using histochemical methods degenerative changes of bronchiolar epithelium were observed.