Inclusion Criteria:  Admission to an ICU. Mechanical ventilation with an endotracheal tube for greater than 48 hours.  Exclusion Criteria:  Contraindication to enteral nutrition administration. Pre-existing history of dysphagia or aspiration. Pre-existing or acute primary central or peripheral neuromuscular disorder. Presence of a chronic tracheostomy (present prior to ICU admission). Pre-existing head and neck cancer or surgery. Coagulopathy resulting in uncontrolled nasal or pharyngeal bleeding. Delirium for more than 72 hours after extubation as assessed by Confusion Assessment Method (CAM-ICU). Extubated for greater than 72 hours. Inability to obtain informed consent from patient or an appropriate surrogate. Age < 18 years.