[Expectoration and inhalation therapy].

We analysed sputum properties based on certain clinical information such as sputum volume, its gross appearance, the diagnosis, and difficulty in expectoration. We also compared sputum properties, clinical information and the effects of inhalation drugs on sputum in vitro, and on this basis evaluated the indications and limitations of inhalation therapy. It appears that inhalation therapy is limited by sputum properties, because the properties of large amounts of sputum, purulent sputum, and sputum expectorated with great difficulty are apparently different from those of other types of sputum. The effect of inhalation drugs on sputum was studied in vitro. Distilled water and normal saline showed as mucolytic agents. Bromhexine was acids in solution. The acidity caused the sputum to gel and reduced its mucolytic effect. Tyloxapole was alkaline in solution. The alkalinity decreased the mucociliary transport rate (MTR). Acetylcysteine had a marked mucolytic effect and decreased the MTR. There was a particular desire to develop drugs which improved MTR, because MTR is impaired by large amounts of sputum and sputum expectorated with great difficulty as well as in the case of sputum from diffuse panbronchiolitis patients.