The available modes of positive pressure assisted ventilation have distinct advantages and disadvantages. Secretions can be suctioned directly from the trachea and major bronchi, but not from smaller airways. When this problem worsens airway obstruction, weaning from the ventilator is likely to become impossible. Despite some dramatic exceptions, impaired airway clearance usually limits the effective duration of assisted ventilation to several weeks for patients with severe CF lung disease. Endotracheal tubes increase the risk of secondary infection with hospital-acquired bacteria, which are often quite virulent.
Verbal communication is impossible with a cuffed tracheal tube in place.
High levels of airway pressure can damage alveolar cells and even rupture into the pleural space, causing a pneumothorax. Mask ventilation is readily reversible and permits coughing, talking and eating. The risks of secondary lung and sinus infections are lower, and less sedation is necessary. The continuing use of the normal respiratory muscles reduces the risk of progressive muscle weakness, compared to tracheal ventilation. Experienced CF clinicians can often provide adequate support with mask ventilation to minimize the need for tracheal ventilation.