Many times, when patients have difficulty swallowing, they are referred to the gastroenterology service for assessment. For these patients, there can be difficulty in any phase of the swallowing (oral, pharyngeal, or esophageal). For this reason, it is important to recognize the etiologies that impact swallowing abilities, and how they can best be addressed.
Dysphagia, or difficulty swallowing, is well known in relationship to etiologies such as cerebrovascular accident, head and neck cancer, Parkinson's disease, and Alzheimer's disease. Occasionally, there are times when a clear etiology for our patient's dysphagia is not evident. Additionally, how providers choose to manage their dysphagia may also contribute to further difficulties.
Sarcopenia Related to Swallowing
Swallowing musculature is skeletal muscle predominantly composed of Type II muscle fibers. These muscles are responsible for fast, powerful, and high force muscle movement. Once a single swallow is initiated, it takes approximately 1 second to complete (Nikhil, Naidu, Krishnan, & Manjula, 2014). If the swallowing power or speed is reduced, this can lead to swallowing difficulty. Recently, sarcopenia was associated as a possible contributor for dysphagia (Cha et al., 2019).
Sarcopenia is characterized by progressive and generalized loss of skeletal muscle. Strongly associated with sarcopenia, oropharyngeal dysphagia has features of geriatric syndromes. In 2013, there was a confirmation of dysphagia and sarcopenia correlation and the term "sarcopenic dysphagia" was introduced (Ozer, Ak[latin dotless i]n, Soysal, Gokcekuyu, & Zarars[latin dotless i]z, 2021).
An effective swallow relies on good timing, tongue or lingual pressure, pharyngeal contraction, laryngeal elevation, airway closure, and pharyngeal/laryngeal sensation. Numerous studies have demonstrated age-related physiologic changes in swallowing, including decreased lingual strength and pressure generation, diminished pharyngeal sensory discrimination, and delayed upper esophageal sphincter manometric relaxation during the swallow (Chen, Golub, Hapner, & Johns, 2009). A decrease in strength, timing, and sensation result in increased difficulty clearing the bolus from the pharynx efficiently and safely.
One of the possible underlying mechanisms of sarcopenic dysphagia is that sarcopenia affects Type II fibers more than Type I fibers; swallowing muscles are heavily composed of Type II muscle fibers (Ozer et al., 2021). With the progressive and generalized loss of muscle from these Type II fibers, this can result in generalized swallowing difficulty. With decreased speed of swallowing, a bolus such as thin liquids can slip away from the oral cavity and into the throat prior to initiating the swallow. Likewise, with decreased strength, swallowing a bolus such as meat or bread can leave material behind in the throat after the swallow. When difficulty is noted, a swallowing evaluation may be recommended.
Use It or Lose It
With the aging population, swallow evaluation referral rates increased an average of 63% between 2007 and 2014. The increased demand for swallow testing will require more trained screeners such as nurses to identify aspiration risk and dysphagia specialists to diagnose and treat dysphagia (Leder & Suiter, 2009). Swallowing difficulty seen at the bedside can result in treatment options such as a downgrade in diet; for example, instead of a diet of regular consistency, minced and moist food options may be trialed (International Dysphagia Diet Standardization Initiative [IDDSI] level 5). Further downgrades that occur might include mildly thick (IDDSI level 2) instead of thin liquids. Downgrades such as these should be made under the direction of a speech-language pathologist. This type of dietary change should be carefully considered as it does not encourage the same muscle use. When muscle is not utilized to its usual capacity, neuromuscular changes occur.
No matter the cause, deconditioning occurs quickly and tends to preferentially affect Type II fibers (Burkhead, 2009). In other words, if you do not use it, you lose it, and swallowing musculature is not immune. Therefore, when diet changes are made, the provider should also be considering the possibility of further weakening the swallowing musculature. Over time, the patient will no longer be able to adequately swallow food consistencies that previously gave no difficulty. Managing the diet for safety while not encouraging atrophy requires clinical expertise and close patient monitoring. For this reason, a speech-pathology consult can be beneficial. Also, an objective swallow study provides information regarding appropriate diet recommendations, head positions, or other strategies that can assist in the safety of oral intake, while providing the best information for developing a plan of care for treatment.
Considerations for Treatment
To overcome the effect of aggravating factors on sarcopenic dysphagia such as physical inactivity and malnutrition, interventions to increase skeletal muscle mass including resistance training and essential amino acid supplementation may be recommended. Oral care and food modification should also be considered to reduce adverse events associated with sarcopenic dysphagia, such as aspiration pneumonia. If these treatments are offered comprehensively, sarcopenic dysphagia could improve and its related complications could decrease (Cha et al., 2019).
Treatment options can assist with decreasing the negative effects of sarcopenic dysphagia. For our geriatric patients, quality of life often becomes the most important factor in dysphagia management. The consequences of dysphagia vary from social isolation owing to the embarrassment associated with choking or coughing at mealtime, to physical discomfort (e.g., food sticking in the chest), to potentially life-threatening conditions. The more ominous sequelae include dehydration, malnutrition, and both overt and silent aspiration (Robbins, Bridges, & Taylor, 2006).
There are also factors to consider for the patient's ability to remain on a regular diet: dentition, cognition, and other medical etiologies that result in dysphagia and a decrease in function and quality of life. Our goal as clinicians is to assist with increasing safety and quality of life while also not encouraging further decline. Often this comes with encouragement from the clinician for the patient to continue eating as normally as possible as long it is safe to do so. Clinicians providing guidance to patients with dysphagia must carefully assess the reason behind the dysphagia and think twice before diet change is used as the first "treatment" option.
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