Leakage of fluid around the cuff of the endotracheal tube (ETT) into the airway is a potentially serious form of microaspiration. The cuff is designed to provide a seal with the airway, allowing airflow through the ETT but preventing passage of air or fluids around the ETT. When this seal is compromised, microaspirations contaminated with gastric contents or bacterially colonized oral secretions can occur that leave the patient susceptible to a host of problems, such as hypoxia, pneumonitis, and respiratory infections.

Hypoxic events have been shown to accompany aspiration in mechanically ventilated patients ¹⁾.