A tracheostomy tube provides an alternative pathway for breathing, bypassing the upper airway through a surgically created opening in the neck called a stoma. The inner cannula is a removable component that fits inside the outer part of the tracheostomy tube. It helps maintain a clear airway and facilitates routine care.
Understanding the Tracheostomy Inner Cannula
The inner cannula is a removable tube that sits within the outer cannula, the main body of the tracheostomy tube. Its primary function is to prevent airway obstruction from mucus and secretions. As a liner, it collects these secretions, preventing them from blocking the main tracheostomy tube.
This design allows for easy removal and cleaning or replacement, which helps maintain a patent airway without needing to change the entire tracheostomy tube. While the presence of an inner cannula can slightly increase airway resistance, its benefit in preventing blockages and simplifying secretion management is important. It also facilitates effective suctioning, as the inner cannula can be removed to clear any plugs.
Exploring Inner Cannula Types
Inner cannulas come in several variations, each designed to meet specific patient needs. A distinction is between disposable and reusable types. Disposable inner cannulas are designed for single use and are replaced after they become soiled, while reusable cannulas are cleaned and reinserted.
Another important classification is fenestrated versus non-fenestrated. Fenestrations are small openings or holes on the shaft of the inner cannula that align with similar openings in the outer cannula. These fenestrations allow air to pass upward towards the vocal cords, which can enable speech and improve breathing by reducing resistance. Conversely, non-fenestrated cannulas are solid tubes without these openings, typically used when speech is not the immediate goal or when there is a need to prevent aspiration.
Routine Care and Replacement
Maintaining the inner cannula is a routine part of tracheostomy care, involving cleaning or replacement to prevent mucus buildup and blockages. For reusable inner cannulas, cleaning involves removing the cannula, soaking it in a solution like half-strength hydrogen peroxide or distilled water with mild soap, and then scrubbing it with a small brush or pipe cleaner. After cleaning, it is rinsed thoroughly with sterile water or saline and allowed to air dry completely before reinsertion.
Disposable inner cannulas are replaced at least once daily, or more frequently if secretions are excessive or thick. Some facilities recommend changing them once per shift (approximately every 8 hours), especially for patients on mechanical ventilation.
Proper hand hygiene is important before and after handling the inner cannula to prevent infection. It is also important to have a spare inner cannula readily available, especially for those whose tracheostomy tube requires it for connection to ventilators or other equipment.
Addressing Common Inner Cannula Issues
Issues can arise with an inner cannula, requiring prompt attention to ensure patient safety. A common problem is a blockage, often caused by thick mucus or a mucus plug. If a blockage occurs, the inner cannula should be removed immediately for cleaning or replacement to clear the airway. This action can prevent a life-threatening obstruction and avoid a complete tracheostomy tube change.
Accidental dislodgement or removal can also occur, which requires assessment of the patient’s breathing and reinsertion if possible and if trained. Signs of a problem with the inner cannula or tracheostomy tube include difficulty breathing, increased coughing, unusual sounds during breathing, or changes in skin color around the stoma. If any of these signs appear or if a blockage cannot be cleared, seek immediate medical attention, as delays can lead to severe respiratory distress.