How can a tracheostomy (trach) tube be too large, causing obstruction?

From the Guidelines

A tracheostomy tube that is too large can cause obstruction by irritating or damaging the tracheal wall, leading to granulation tissue formation or tracheal stenosis, and therefore, selecting a tracheostomy tube of the proper diameter, length, and curvature for the individual patient is crucial to minimize potential complications, as stated by the American Thoracic Society 1. To prevent this:

• Always use the appropriate size trach tube based on the patient's anatomy and clinical needs, ensuring the tube size does not exceed two-thirds of the tracheal lumen, unless a fenestrated tube is used 1.
• Regularly assess for signs of obstruction, such as increased work of breathing, decreased air movement, or difficulty passing a suction catheter.
• Perform routine bronchoscopy to evaluate the tracheal lumen and check for any tissue overgrowth or narrowing.
• If obstruction is suspected, downsize the trach tube immediately and consult with an ENT specialist.
• Consider using a cuffless or smaller diameter tube if long-term tracheostomy is required. The trachea's internal diameter is typically 15-20 mm in adults, and a tube that's too large can cause pressure necrosis of the tracheal mucosa, leading to inflammation and tissue overgrowth, which can gradually narrow the airway, compromising ventilation and increasing the risk of respiratory distress, as noted in the care of children with chronic tracheostomy 1.

Key Considerations

• The diameter of the tracheostomy tube should be selected to avoid damage to the tracheal wall, to minimize work of breathing, and, when possible, to promote translaryngeal airflow 1.
• The curvature of the tracheostomy tube should be such that the distal portion of the in situ tracheostomy tube is concentric and colinear with the trachea, as assessed by neck/chest radiographs or flexible bronchoscopy 1.
• All tracheostomy tubes should have a 15-mm “universal” adapter to allow bag ventilation in an emergency 1.

From the Research

Tracheostomy Tube Obstruction

A tracheostomy (trach) tube can be too large, causing obstruction due to several reasons:

• Improper placement of the tube, which can cause protrusion of the tube into the tracheal lumen, leading to obstruction of the airway 2
• Malfunction of the tracheostomy tube, which can lead to complications such as tracheal obstruction 3
• Tracheal stenosis, which can occur as a complication of tracheostomy tube placement, causing obstruction of the airway 4
• Tracheal obstruction can also occur due to the formation of granulation tissue or scar tissue around the tracheostomy tube, which can narrow the airway and cause obstruction 5

Causes of Tracheal Obstruction

Tracheal obstruction can be caused by:

• Prolonged mechanical ventilation, which can cause tracheal injury and obstruction 5
• Improper sizing of the tracheostomy tube, which can cause the tube to be too large or too small for the patient's trachea 6
• Malpositioning of the tracheostomy tube, which can cause the tube to obstruct the airway 2
• Tracheal anomalies, which can make it difficult to properly place the tracheostomy tube and cause obstruction 6

Prevention and Treatment of Tracheal Obstruction

Prevention and treatment of tracheal obstruction include:

• Proper placement and sizing of the tracheostomy tube 6, 2
• Regular monitoring of the patient's airway and tracheostomy tube 4
• Use of a longer tracheal tube or tracheal stent to bypass the obstruction 5
• Treatment of underlying conditions that may be contributing to the obstruction, such as tracheal stenosis or granulation tissue formation 4, 5