On the pseudomembranous laryngotracheitis after endotracheal anesthesia, 10 cases in our hospital and 54 cases in other hospitals were statistically studied. It was found in 10 cases among our 318 cases of endotracheal anesthesia i.e. 5 cases among 115 cases of hypotensive
anesthesia and 5 cases among 203 usual methodes. Nine of them were female and one was male. Three of them were severe and cured by tracheotomy. For all cases we used ether mainly. The intubation was difficult in 2 of them and easy in other caces. The internal pressure of the cuff was about 50 mmHg except for 2 cases. The pressure seemed to be not so high and the duration of incubation was 2-8 hours. The histological findings of every pseudomembrane showed that it consisted of fibrinogen with many polymorphologic leucocytes. From the pseudomembrane bacteria were positive in 5 cases among 6 examined. Statistics show that: this complication has occurred in 54 cases of 38,473 cases and its rate is 0.14%. It was more in female. The pressure in cuff and continuation of anesthesia seemed to have no influence upon it. In those cases, in which the tube was not sterilized and fluid paraffin or nothing was used for lubricant, it occured more frequently.