Cleaning and Removal of the Inner Cannula
The inner cannula is an inner tube inserted within the main outer cannula of the tracheostomy tube and is useful for individuals who require secretion management. The inner cannula reduces the diameter of the tracheal tube lumen, increasing resistance and work of breathing. However, if the tube becomes blocked, the inner cannula can easily be removed and replaced, while maintaining the outer tube’s lumen. This may avoid the trauma of an emergency complete tube change.
The inner cannula can be disposable or non-disposable. Disposable inner cannulas are removed and replaced while non-disposable inner cannulas are cleaned and reinserted. Different tracheostomy tubes have different types of inner cannulas. For some tracheostomy tubes (Kapitex and Shiley), the inner cannula must be in place to provide a 15mm hub to connect to the ventilator circuit, resuscitation equipment, speaking valves and caps. Patients with these tracheostomy tubes should have a spare inner cannula in close proximity to the patient at all times.
Cleaning the inner cannula is important to removing secretions to reduce the risk of a blockage and/or infection. Secretions can adhere to the inner cannula which can reduce the inner diameter resulting in increased work of breathing and potentially block the patient’s airway. The inner cannula should be removed and inspected once per 8 hour shift or if the patient shows any signs of respiratory distress. For patients on mechanical ventilation, it may not be feasible to disconnect the patient from the ventilator for inspection or cleaning of the inner cannula and should be a decision based on the risks and benefits. Document if the inner cannula was not changed and the reasons.
The literature is inconclusive as to the most appropriate cleaning solution to use.
Disposable inner cannulas are also available from some manufacturers which may increase compliance of inner cannula care. This comes with a cost and environmental considerations.
Video of cleaning and changing the inner cannula from National Tracheostomy Safety Project
Procedure for cleaning the inner cannula
Prior to any procedure, explain and discuss with the patient as appropriate. Wash hands and use appropriate protective equipment to prevent the spread of infection. The tracheostomy tube may require suctioning prior to removal of the inner cannula. With one hand, stabilize the outside of the tracheostomy tube and with the other hand remove the inner cannula. The inner cannula is inspected for secretions and other debris. If clean, it can simply be reinserted. If it needs to be cleaned the spare inner cannula can be placed while cleaning. The inner cannula can be cleaned with saline and a foam brush or gauze. Shake off excess water and leave it to dry in a container prior to reuse. If the inner cannula is unable to be cleaned adequately due to tenacious secretions, dispose of it and replace with a new inner cannula. Tubes should not be left in water as this can result in bacterial growth. Commercial cleaning packages are available that may make cleaning easier and increase compliance.
If there is difficulty removing the inner cannula, call for help. Secretions may have thickened or granulation tissue may prevent removal of the inner cannula.