Untersuchungen zur Anwendbarkeit der Atemkondensatgewinnung beim Pferd und ihre potentiellen Einsatzmöglichkeiten in der Lungendiagnostik
Abstract
The aim of the study was to develop a method to collect breath condensate in horses. To collect breath condensate without contamination from the upper airways in horses, which are obligate nose-breathers, a plastic tube was placed in the trachea by passing it through the ventral nasal ductus and larynx. Because of its internal diameter of 11 mm, only a small part of the exhaled air passed the tracheal tube (ventilation of a calm horse ca. 800 l/10 min, volume passing the tube ca. 40 l/10 min). The end of the tube was fixed on a teflon collecting tube, which was placed in a double sided cooling device1. A non-rebreathing valve on the end of the collecting tube guaranteed, that only expired air reached the collecting tube. In 30 horses, a pneumotachographic head2 (FLEISCH Nr.1) was placed in between the teflon tube and the non-rebreathing valve to register with a pneumotachograph3 the expiratory volume, which really passed the tube. The expiratory air was collected for 10 minutes. The temperature of the cooling device was -20 °C. The collection of breath condensate was performed successfully in 68 of 72 horses. In 4 horses it was not possible to collect condensate. 1 horse got epistaxis due to inadverte placement of the tube in the middle nasal meatus. In 3 ponies the nasopharynx was too short, resulting in stopping of the tube in the recessus pharyngeus. In 89,7 % of the horses it was possible to place the tube in the trachea without sedation. After recurrent application of this method (4 times in 3 days), only a mild redness of the tracheal mucosa was seen. It was concluded that recurrent sampling of breath condensate is possible with just minor mucosal irritations. The volume of the collected condensate was determined after thawing, weighning and passing it into sampling tubes. The breath condensate volume was mainly influenced by the respiratory flow and the expiratory volume passing the tube. The results of the study show, that the sampling of breath condensate by a tracheal tube is possible routinely in horses. The tube on the one hand reduces the expiratory volume, so that it becomes possible to collect breath condensate with a device which was constructed to freeze the smaller human expiratory volume. On the other hand by using a tracheal tube, a contamination of the exhaled air from the upper airways is avoided.
 |