We know that intubation can impact the swallow. How does intubation affect swallowing?
Is it a strength deficit or a sensory deficit?
This post will take a look at studies that look at the impact of intubation on sensation of the tongue and the larynx.
What about the effects on the tongue?
Su, H., Hsiao, T. Y., Ku, S. C., Wang, T. G., Lee, J. J., Tzeng, W. C., … & Chen, C. C. H. (2015). Tongue weakness and somatosensory disturbance following oral endotracheal extubation. Dysphagia, 30(2), 188-195.
We all know how important a role the tongue plays in swallowing.
This study looked at 30 patients, aged 20 and older, with oral intubation of more than 48 hours. Patients were excluded if they had a history of neurologic disease, had head and neck deformities, had a prior history of swallowing difficulty, were delirious or unable to respond to questions or received tracheostomy.
Eleven patients were unable to complete the 14 day follow-up from the intubated group due to death, re-intubation or discharge.
Tongue strength was measured by the Iowa Oral Performance Instrument (IOPI). Comparison of lingual strength was measured to a comparison group from dental and geriatric outpatient groups.
Sensation was measure by using light touch points, oral stereognosis, and two-point discrimination with standardized protocols.
Measurement of strength and sensation were measure within 48 hours of extubation, 7 and 14 days post extubation for the extubated patients and one time for the comparison group.
The study showed that patients with oral intubation had decreased sensation (which gradually returned within 14 days) and decreased strength (which persisted.) There is still a question of whether strength and sensory deficits directly related to intubation or if there was pre-existing dysphagia.
Extubated patients took a median of 2 days to trial water and were able to resume total oral intake in 7.9 ± 4.8 days. (No patient had any intervention for swallowing during the 14 day study.)
Can intubation affect laryngeal sensation.
Borders, J. C., Fink, D.C Levitt, J. E., McKeehan, J., McNally, E., Rubio, A., … & Warner, H. (2019). Relationship between laryngeal sensation, length of intubation, and aspiration in patients with acute respiratory failure. Dysphagia, 34(4), 521-528.
This study looked at laryngeal sensation following extubation. We know that laryngeal sensation is critical for airway protection during swallowing.
Patients in this study had a Flexible Endoscopic Evaluation of Swallowing (FEES) within 72 hours of extubation. Both fiberoptic and distal chip scopes were used during FEES. “Boluses were administered in the following order: ½ and full teaspoon of ice chips; 5 ml, 15 ml, and 2 oz nectar-thick liquid (Thick & Easy®, Hormel Health Labs, Austin, MN); 5 ml and 10 ml puree; 5 ml, 15 ml, and 2 oz thin liquid; ¼ piece of graham cracker; 3 oz water swallow test. If aspiration was visualized on a small bolus (i.e., 5 ml), then the larger bolus within that consistency was skipped and the next consistency was
This study included 103 patients of 141 initial patients. 51 of those patients demonstrated an absent laryngeal adductor reflex LAR (23 with a unilateral LAR and 28 with a bilateral LAR. Patients had to be at least 18 years old, admitted to the ICU and had an endotrachial tube for more than 48 hours.
Patients were excluded if they had contraindications to enteral nutrition, prexisting or acute neuromuscular disorder, history of dysphagia, head and neck cancer or surgery or presence of a trach.
Decreased laryngeal sensation correlated with the presence of secretions. Decreased laryngeal sensation was also correlated with aspiration on FEES in patients with a shorter time of intubation resulting in recommendation of restricted liquid and solid diet. 47% of patients with decreased laryngeal sensory also had aspiration. 23% of patients with intact LAR aspirated. 39% of patients with bilateral LAR deficit and 57% or patients with a unilateral LAR deficit had aspiration. 16% of patients with absent LAR and 6% of patients with an intact LAR had silent aspiration .
It was found that there is a high prevalence of laryngeal sensory deficits following extubation associated with secretions, aspiration and modified diet recommendations.
“Altered laryngeal sensation was associated with aspiration and shown to have a more profound effect on aspiration risk in patients with a short length of mechanical ventilation. The presence of secretions and modified diet recommendations were also correlated with altered laryngeal sensation.”