What is the purpose of a cuff? For one, it directs airflow through the tracheostomy tube in and out of the lungs. Inflation allows the clinician to control and monitor ventilation when the patient is on mechanical ventilation. Secondly, inflation can reduce the amount and speed of aspiration, providing some protection in the patient who may have gross emesis or reflux when aspiration of gastric contents may occur.
How does a deflated cuff lower the risk of aspiration?
Aspiration occurs at the level of the vocal cords. A tracheostomy is placed below the vocal cords. Thus material sitting on top of the cuff is already aspirated. Aspirated and pooled secretions sitting on top of the cuff has the potential to colonize leading to infection. Secretions sitting on top of the cuff also have the potential to harden forming a mucous plug which could easily fall into the lungs.
- In a randomized controlled study of critically ill patients, there was significantly less respiratory infections in the group with deflated cuffs. This for one is due to a decrease in silent aspiration while eating and drinking likely due to a restored laryngeal and pharyngeal sensation and cough reflex.
- In a retrospective study, silent aspiration was 7.2% in cuff deflated patients while silent aspiration in inflated cuff patients were 22.6%.
To inflate or deflate
Deflating the cuff is the way to go (Bivona foam trach is the exception). After the first 24 hours post tracheostomy, benefits of cuff deflation can be safe. Some airflow is reestablished through the upper airway when the cuff is deflated. This allows airflow to pass through the vocal cords causing them to vibrate resulting in phonation. Aspiration has already occurred when a substance has reached the cuff, as the cuff is below the vocal cords. Cuff deflation may speed along decannulation. When decannulation is not the end goal, cuff deflation still shows benefits as far as communication, swallowing, and natural physiology.
General rules of thumb
- When deflating the cuff, warn the patient that they will feel a change in airway sensation
- If the patient is continuously coughing that does not subside in time, reinflate the cuff. Persistent coughing may be due to difficulty swallowing, excessive oral secretions, and/or poor cough
- When the cuff is deflated, some airflow is reestablished through the upper airway resulting in vibration of the vocal cords
- Cuff deflation leads to a more natural physiology in turn speeding up rehabilitation process
- Cuff inflation can lead to silent aspiration
- Ding, R. & Logeman, J. (2005). Swalllow Physiology in Patients with Trach Cuff Inflated or Deflated: A Retropective Study. Head &Neck. Sep;27(9):809-13
- Hernandez,G. et al. (2013). The Effects of Increasing Effective Airway Diameter on Weaning from Mechanical Ventilation Tracheostomized Patients: A Randomized Control Trial. Intensive Care Medicine. Jun;39(6):1063-7