COVID-19 Impact on Swallowing Function
When COVID-19 was declared a pandemic in March 2020 in the United States, many of us were unsure about what the impact on the healthcare world would be. This held true for Speech-Language Pathologists (SLPs) across the nation who were deemed "non-essential" employees and subsequently furloughed or given reduced hours. In fact, COVID-19's detrimental impact on the body and respiratory system has led to the use of oxygen, CPAP, BiPAP, suctioning, and in extreme cases, mechanical ventilation, related impaired cognitive and communication functions (including those needed for safe eating), and related impaired swallowing ability, or dysphagia.
According to the American Speech and Hearing Association (ASHA), dysphagia is a swallowing disorder involving all aspects of chewing, actively swallowing, and transporting the food/liquid (referred to as a bolus). Untreated dysphagia may lead to more medically complicated issues such as "malnutrition and dehydration, aspiration pneumonia, compromised general health, chronic lung disease, choking, and even death" (ASHA, n.d.). So why is COVID-19 impacting swallowing function? Thoughts are that, well, it's complicated.
COVID-19 has known changes in sensory input (think the loss of taste and smell, which are common symptoms of COVID-19) and related atrophy or weakening of musculature, which can lead to respiratory-swallow dyscoordination. Sensory input is required in order to trigger a motor response. When we are talking about swallowing, taste and swallow responses share the same neurologic pathway, so changes in sensory input can make the individual less likely to want to eat. Reduced eating results in malnutrition and dehydration, thus making it more difficult for the individual to recover.
Another consideration is that COVID-19 leads to an elevated diagnosis of pneumonia. Impairments in respiratory-swallow coordination can result in atrophy resulting in slower transit of the bolus and increased residue, thus elevating the risk of penetration (food/liquid/saliva reaching the vocal folds) and aspiration (food/liquid/saliva going below the vocal folds into the lungs). In cases of individuals unable to eat due to ventilation, the risk of development of oral bacterias and saliva aspiration is elevated.
COVID-19 also results in intubation and post-extubation dysphagia cannot be ignored. The risk of aspiration increases immediately following extubation due to residual effects of sedating medications, delirium and/or reduced level of alertness, atrophy and weakness, alteration in airway sensitivity, possible glottic injury during/after extubation, and reduced breathing-swallow coordination ((Mansolillo, 2021, p. 38). Patients who suffer respiratory failure due to COVID-19 are not receiving tracheostomies as rapidly as individuals with "typical" respiratory failure, so total intubation time is longer (Mansolillo, 2021, p. 42). Individuals with COVID-19 also were kept NPO (nothing by mouth) for longer and needed more therapy sessions to resolve their dysphagia compared to non-COVID-19 patients (Mansolillo, 2021, p. 44).
The medical SLP serves a crucial role in supporting clinical team members, doctors, and nurses, in assessing the patient's swallow safety after COVID-19, in determining what types of food and liquid are safest, and even when food and liquid can be safely provided. The role of the SLP in evaluating and treating individuals with COVID-19 for dysphagia could not be more imperative during this time. Early identification of dysphagia and early SLP referrals can help to reduce the risk of aspiration, related illness, and other non-COVID-specific medical complications that reduce recovery and prolong hospital stays, all of which help people survive this terrible virus and get home to their families faster.
American Speech-Language-Hearing Association. (n.d.). Adult dysphagia. American Speech-Language-Hearing Association. https://www.asha.org/practice-portal/clinical-topics/adult-dysphagia/.
Mansolillo, A. (2021, February 2). COVID-19 and Dysphagia: What We Need to Know.