Uses
Advantages
Disadvantages
Dual Cannula
  • Generally preferred in adult patients (inherently safer) and recommended in those on lower respiratory support
  • Permits the lumen to be cleaned to prevent blockage
  • Reduces the risk of airway obstruction from retained secretions
  • Reduces the frequency of tracheostomy tube change from 7-10 days to >28 days
  • The presence of an inner cannula reduces the internal diameter of the airway
  • May increase the resistance to movement of air and increase the work of breathing, contributing to weaning difficulty
  • Necessitates repeated circuit disconnection to facilitate inner cannula exchange
Single Cannula
  • Most common in paediatric patients
  • May be useful in adults with high respiratory support requirements on humidified closed circuits (benefits of removable cannula may be less marked)
  • May reduce the resistance to movement of air and decrease the work of breathing
  • Reduces circuit disconnections for tube exchange
  • Higher risk of blockage and airway obstruction
  • Necessitates external tube change every 7-10 days