Mucosal changes in the trachea and main bronchi of newborn infants after naso-tracheal intubation.

Permanent sequelae of nasotracheal intubation are uncommon, but acute ulceration and squamous metaplasia occur. Histological sections from the trachea and main bronchi were examined in 12 infants. A nasotracheal tube had been inserted during the first two weeks of life of these infants and had been in place for more than one week. In four cases the patient died some time (7 to 108 days) after extubation. Similar sections from patients who were not intubated, intubated only for attempted resuscitation, or intubated for several hours were studied for comparison. The sections were classified according to the degree of mucosal loss and metaplasia, and the extent of the lesions was estimated. Squamous change was seen in most sections from all 12 patients with the exception of one who died 57 days after extubation. Some respiratory epithelium was seen in all patients. In the eight patients who died while intubated, the changes were more marked in the right main bronchus than the left in seven, and more marked in the lower trachea than the upper in five. In the two patients intubated for several hours, in addition to mucosal loss, early metaplasia was seen. It is suggested that mucosal loss is replaced by the squamous metaplasia, and that trauma caused by suction catheters in the lower trachea and right main bronchus is more extensive than that due to the endotracheal tube itself.