Gastroesophageal reflux as an etiologic factor in laryngeal complications of intubation.

Significant complications are encountered in some patients as a result of prolonged endotracheal intubation. The finding of low gastric pH values at postmortem examination in patients whose larynx was severely traumatized after endotracheal intubation suggested that gastroesophageal reflux (GER) is an important factor in the pathogenesis of these problems. To evaluate the occurrence and character of GER as well as its effects upon the larynx and trachea of intubated patients, clinical observations and several animal models were employed. Monitoring of pH values for GER was performed in intubated patients both in the operating room and the intensive care unit with a 40% incidence of GER in ICU patients not receiving antacid therapy. After exposure to gastric juice, marked inflammation and necrosis were observed in the larynx of rabbits, and a significant reduction of mucociliary flow was found to occur in the dog's trachea. The physiology and mechanisms of these events are discussed and indicate that GER may play an important role in the development of permanent laryngeal and tracheal injury in the intubated patient. It is recommended that pharyngeal pH be monitored in intubated patients because their altered state of consciousness may predispose to gastric reflux. When GER is encountered, initiation of treatment should be undertaken because prevention is considerably more effective than subsequent treatment.