Subglottic ulceration and healing following endotracheal intubation in the neonate: a morphometric study.

In neonates, acquired subglottic stenosis is the most serious long-term complication of endotracheal intubation and is due primarily to posttraumatic fibrosis of the infant larynx. We have examined 78 larynges, 75 of which were intubated, from infants ranging in gestation from 22 to 40 weeks, and who survived from a few hours to up to 300 days. Each larynx was morphometrically assessed for the extent of acute injury, indicated by the percentage of epithelial loss, and healing, indicated by the percentage of a subglottic ulcer covered by metaplastic squamous epithelium. Results show that acute injury is almost invariable, and up to 100% of the subglottic epithelium may be lost within a few hours of intubation, but that progression of injury is relatively short-lived. Ulcer healing starts after a few days, rapidly progresses from day 10, and in the majority of cases is complete after 30 days. This study suggests that long-standing acute injury in the subglottis is the exception rather than the rule, even with the endotracheal tube remaining in place.