Laryngeal Complications of Endotracheal Intubation

Abstract

An endotracheal tube placed in the larynx, even for a short time, causes at least superficial mucosal damage, an injury that normally heals readily. Long-term intubation, on the other hand, may cause pressure necrosis that can extend into submucosa, perichondrium, and eventually cartilage. The sites of involvement include the medial surface of the arytenoid cartilages, vocal processes, cricoarytenoid joints, posterior glottis, and subglottis. We review the pathogenesis, endoscopic recognition, classification, and progression of intubation injuries and examine the many variables that influence them. Diagrammatic flow charts trace the acute injuries through to their chronic sequelae, including subglottic stenosis, which is commoner in infants and children, and posterior glottic stenosis, which is commoner in adults. Systematic endoscopic assessment, under general anesthesia, using rigid telescopes to evaluate laryngeal damage during intubation is recommended and critically discussed. Endoscopy permits an informed judgment with regard to continuation of intubation. Depending on the severity and depth of ulceration, intubation can be continued (sometimes with a tube of smaller diameter) or tracheotomy performed, with an awareness of the attendant risks and benefits. Unnecessary tracheotomies may be avoided. Further, it may be possible to minimize untoward outcomes of prolonged intubation by using management techniques directed at known risk factors.