Patients with tracheostomy and mechanical ventilation are at high risk of aspiration with up to 87% of patients who are provided with oral intake aspirating (Elpern et al, 1994), with the majority of those silently aspirating. Silent aspiration is when food, liquid, or secretions go into the airway and there are no overt signs such as coughing or throat clearing. This is concerning, as aspiration can result in pneumonia, especially in an already vulnerable population. Despite the high rate of aspiration, many individuals with tracheostomy and mechanical ventilation can safely take some oral intake following a proper assessment by a trained speech-language pathologist, which can reduce delays in beginning oral intake and reduce complications from unsafe oral feedings.
In the population with tracheostomy and mechanical ventilation, dysphagia is often multi-factorial.
The underlying medical diagnosis, acuity of the patient, and the reason for the initial tracheostomy tube are important considerations. Tracheotomy may be performed on individuals with neuromuscular diseases such as stroke, ALS, Guillian Barre, MS, Parkinson’s Disease, and muscular dystrophy. Obstructive airway disease, head and neck cancer/surgery and adult respiratory distress syndrome may also result in the need for tracheotomy. Dysphagia can result from the impact of these medical conditions.
Another factor that may increase the risk for aspiration is that most individuals with tracheostomy are initially orally intubated with an endotracheal tube. This is a tube that goes in the mouth through the larynx and into the trachea. Swallow studies within 24 hours of the oral intubation tube being removed have shown high rates of aspiration, with a high proportion being silent aspiration. The endotracheal tube passes through the vocal folds, which can damage the folds, particularly during emergent intubation, multiple intubations, and extubation. This places the individual at higher risk of aspiration since the vocal folds are largely responsible for airway protection.
Finally, there are reports of some specific effects of the presence of a tracheostomy on swallowing, particularly when the cuff is inflated. This includes:
- Impaired laryngeal elevation (Ding & Logemann, 2005; Amethieu et al, 2012; Jung, S. et al, 2012; Logemann et al, 1998).
- Reduced subglottic air pressure (Gross et al, 1994; Gross et al, 2003)
- Desensitization of the larynx (Ding & Logemann, 2005; Amethieu et al, 2012; Seidl et al, 2005).
- Reduced effectiveness of the cough reflex
- Disruption of the vocal fold function (Sasaki CT et al, 1977; Shaker, R et al, 1995).
For further information of the specific studies, please see Tracheostomy Education.
Advantage of FEES for Trach and Vent Population
Due to the high rates of aspiration and silent aspiration, instrumental assessments are strongly recommended. The modified barium swallow study (MBSS) or a flexible endoscopic evaluation of swallowing (FEES) are the gold standards. If use of the speaking valve is time limited, the SLP may assess different conditions such as having the cuff inflated, deflated and valve/cap on to determine the safest strategies for feeding.
There are significant advantages to FEES in the tracheostomy and mechanically ventilated population including:
- secretions are able to be assessed in a population where it may be unsafe to provide foods and liquids
- No barium or radiation
- FEES is not time dependent and can assess patient fatigue over a meal
- No transportation which is especially advantageous given the difficulty of transporting the tracheostomy and ventilator supplies.
- Potentially lower costs and less time spent than MBSS