Airflow through the different tubes

Fig 1 shows a cuffed tracheostomy tube in situ. Airflow should only be through the tube to the lungs, allowing positive pressure ventilation if the tube is correctly sited.

 

In a deflated cuffed tube or an un-cuffed tube, airflow will be through the upper airway and tracheostomy tube as in the centre figure (Fig 2).

 

With a fenestration tube, airflow will be increased through the upper airway and tracheostomy tube as in the right-hand figure (Fig 3).