Temperatur und Feuchtigkeit der Luft in den Atemwegen

Thermal-Dilution Technics

“…Breathing air at -35° C. caused no significant change in the temperature difference. Mather and co-workers 11 foimd that in nine of 12 dogs the pulmonary artery was warmer than the left atrium and noted a mean increase of this difference of less than 0.02° C. on exposure to an atmosphere of -.18° C. These findings together with those of Verzar and co-workers, 8 which showed the completeness of temperature and humidity equilibration in the respiratory tract of the dog even at low (-5° C.) ambient temperatures, indicate that the effects of breathing on intrapulmonary blood temperature are insignificant. Even in man, in whom the air-conditioning capacity of the respiratory tract is less efficient than in the dog, maximal hyperventilation has been shown not to affect the temperature in the small pulmonary arteries.…”

“…The pulmonary capillaries, however, are in a special situation in so far as they are enclosed by the alveolar air which appears to be A r ery largely protected from temperature fluctuations and entirely so from those in humidity even under the least favorable atmospheric conditions. 8 It is to be expected that with the vast area available for heat exchange, the thinness of the alveolar walls and the low thermal capacity of air, temperature equilibration will occur between the pulmonary capillary blood, the alveolar walls and the alveolar air. Even so, the quantity of heat exchanged by the alveolar air will be negligibly small.…”

Respiratory Mucosal Vascular Responses, Air Conditioning and Thermo Regulation

“…In the dog, whose maxillary turbinates are large and complex, the responses, as shown by the change in condition of expiratory air, are considerably greater than in man, whose turbinates are small and simple. The experiments of Verzar, Keith and Parchet (1953) also demonstrate a higher degree of air conditioning in the nose of the dog than in the nose of man.…”

“…It will be seen for instance, from the observations of Verzar, Keith and Parchet (1953) that with a dog in ambient air of temperature -5°C, expiratory air at the anterior nares was only 2i°C, whereas with a clothed man in similar conditions expiratory air was found to be 29°C. (Cole, 1954)-It has been shown above that the upper respiratory mucosal temperature is always below that of the body and that, since its re-warming by blood-borne heat is a slow process, change in its temperature between respiratory phases is very slight.…”

Recordings of Respiratory Air Temperature

“…From the results of Perwitzschky (1927), Seeley (1940), Verzar, Keith and Parchet (1953) and Webb (1951) it would appear that with resting ventilation in temperate conditions there is a temperature gradient of about 5° C. (29 to 34°) in the inspiratory air column between the post nasal space and the entrance to the larynx, so that oropharyngeal inspiratory air temperature would lie somewhere between these values.…”