[Effects of ventilation with defined formaldehyde concentrations on lung function and lung structures. Animal experiments on the noxiousness of formaldehyde residues after disinfection in the aseptor (author's transl)].

Having seen the development of fatal pneumonias in ventilated patients, the cause of which was assumed to be the presence of residual traces of formaldehyde in the air in the respirator Kilian and Haug showed in 1973 initial formaldehyde concentrations up to 0.2 ppm in the ventilatory air of respirators correctly disinfected in the Aseptor. To study the effects of formaldehyde on lung function and lung structures, 23 young pigs were automatically ventilated with defined formaldehyde concentrations during 6 hours. The concentrations used were 0.02 ppm, 0.2 ppm and 2.0 ppm (double of the maximum permissible concentration). We found no differences in lung function, as shown by compliance measurements and arterial blood gas analysis. No radiological differences were in the thorax. Histologically, there were only slight alterations in lung structure in the group ventilated with double the maximum permissible concentration of formaldehyde. We conclude that the disinfection of respirators using formaldehyde in the Aseptor will remain the method of choice.