[The influence of Halothane on surfactant activity of the lung (author's transl)].

Halothane, momentarily the most popular inhalation anaesthetic, was examined in respect of its surfactant irritating properties in 13 rabbits. After five hours IPPB-anaesthesia with this compound there was a highly significant fall of the compliance quotient (CQ), at the moment the most reliable criterion for the surfactant activity "in situ", from 3.34 to 2.76. Lung histology revealed patchy atelectasis, dystelectasis and interstitial edema. In contrast to this remarkable mechanical and structural deterioration, blood gas analyses showed a surprising stability of gas exchange, hinting a tremendous functional reserve. Postnarcotic examination of lung extracts in the Wilhelmy balance exhibited no persistent damage of the specific alveolar lining layer. On the basis of these experimental findings we recommend that halothane should not be used in patients with preexisting impairment of pulmonary surfactant system.