[The determination of the earliest signs of cell damage after translaryngeal intratracheal long-term intubation in rabbits. A light- and electron-microscopic study].

Eighteen New Zealand rabbits were artificially respired, orotracheally with a cuff pressure of approximately 35 mm Hg, for between 2 and 36 h. After 2 h artificial respiration cell degeneration was seen in the area of the cuff, above the cartilage rings, in the form of cytoplasmic degeneration. After a 4 h intubation period an epithelial loss was seen. The basal membrane was intact. A connective tissue oedema, which was limited to the region of the epithelial lesion, became more wide-spread over the 36 h of intubation. A well-developed ulcer could be identified under the light microscope after 36 h. Increased mucous production as well as an increase in bacteria could be observed after 4 h. At no time could a degeneration of the cartilage be seen in the electron micrographs. The intercartilaginous area also remained free from cell degeneration although signs of vascular congestion could be seen.