Dysphagia and the normal swallow
Dysphagia is difficulty moving food from the mouth to the stomach. The term can also be expanded to include behavioral, sensory and motor acts used for the preparation of swallowing. This may include awareness of the eating situation and recognition of the food. It can be due to impaired coordination, obstruction, or weakness affecting swallowing biomechanics. The terms penetration and aspiration are used to describe different degrees of abnormal airway protection that are associated with eating and drinking. Penetration occurs when material enters the laryngeal area to the level of the true vocal folds; aspiration occurs when material moves below the true vocal folds and enters the trachea.
Swallowing disorders may occur for a variety of reasons including structural damage, neurological disorders, laryngeal cancer and congenital abnormalities.
Prevalence of Dysphagia
The prevalence of dysphagia increases with age and is particularly problematic for geriatric patients. The risks can be devastating to this population of patients (Morris, 2006; Wilkins, 2007). Early identification and treatment of swallowing problems can have a significant positive impact on overall health and quality of life.
- Approximately 7%-10% of adults older than 50 years have dysphagia, although this number may be artificially low because many patients with this problem may never seek medical care.
- In people over 60, the prevalence of dysphagia is 15% to 40%. The reported prevalence of dysphagia in long-term care facilities, including assisted living and nursing homes reached up to 66% in some studies (Spieker, 2000; Robins, 2003)
Video of the normal swallow process
Quick overview of the swallow process:
Swallowing is a complex and coordinated neuromuscular process consisting of both voluntary and involuntary activity. It involves
Oral, pharyngeal and esophageal phases of swallowing:
Images A and B demonstrate the oral phase os swallowing. This phase begins when the tongue begins posterior movement. The tongue makes a stripping action with the bolus against the hard palate to move it posteriorly. This process takes from 1 to 1.5 seconds to complete.
Image C is where the trigger of the swallow occurs. As the food is propelled posteriorly, sensory receptors in the tongue and oropharynx are stimulated. Information is sent to the cortex and brainstem. This initiates the pharyngeal swallow pattern. The trigger usually occurs at the anterior faucial arch in normal, young individuals. Individuals over 60 years are not seen to trigger the swallow until the bolus reaches the middle of the tongue base (Logeman, 1998).
Images D and E show the pharyngeal phase of swallowing. This phase begins when the pharyngeal swallow is triggered. When this happens the velum elevates and closes the velopharyngeal port to prevent material from entering the nasal cavity. The base of tongue contracts to contact the posterior pharyngeal wall. The larynx elevates and moves anteriorly. There is also closure of the larynx at the true vocal folds, the false vocal folds, and the epiglottis. Furthermore, contraction of the pharyngeal constrictors occurs from top to bottom. The elevation of the hyoid bone is followed by relaxation of the cricopharyngeal sphincter to allow food to pass down the esophagus.
Image F shows the final phase of the swallowing process. Once the food enters past the cricopharyngeal sphincter (upper esophageal sphincter), the esophageal phase begins. In this phase a peristaltic wave pushes the bolus sequentially from the cervical esophagus down until the lower esophageal sphincter opens to allow the bolus to enter the stomach . The normal time for a bolus to pass from the UES to the gastroesophageal juncture or LES varies from 8 to 20 seconds (Mandelstam & Lieber, 1970).
The act of swallowing usually interrupts the expiratory phase of breathing, while the completion of expiration occurs when swallowing ends. In situations where the swallowing is initiated during the inspiratory phase of ventilation, a brief expiration may ensue after completion of swallowing. Abnormalities of swallowing could result from defects in any of the components of the stages of swallowing enumerated above.
Evaluation of Swallowing Disorders:
Individuals with known or suspected oral or pharyngeal dysphagia should be seen by a speech-language pathologist to evaluate the swallow function.
Bedside swallow evaluation:
A bedside swallow evaluation is a screening process used by speech-language pathologists (SLPs) to assess dysphagia. The purpose is also to establish a possible cause for dysphagia, assess the patient’s ability to protect the airway, determine the possibility of oral feeding or recommend alternative means of nutrition management, determine the need for additional diagnostic tests or referrals, and to establish baseline to chart changes in feeding function of patients with progressive diseases. SLPs look for signs or symptoms of possible oral or pharyngeal dysphagia.
1. Comprehensive chart review- Look at past and present medical history, progress notes, and chest x-rays. Infiltrates in the lungs may represent aspiration, especially in the right lower lobe. The location is often gravity dependent, and depends on the patient position. Generally the right middle and lower lung lobes are the most common sites of infiltrate formation due to the larger caliber and more vertical orientation of the right mainstem bronchus. Patients who aspirate while standing can have bilateral lower lung lobe infiltrates. (Swaminathan, Anand). Infiltrates are not the only determinate of aspiration pneumonia and should be differentiated from aspiration pneumonitis.
At risk populations include partial laryngectomy, recurrent pneumonia, brainstem stroke, laryngeal trauma, Guilian Barre’, bulbar palsy, mystenia gravis, motor neuron diseases, Parkinson’s Disease, anoxia, radiation of head/neck, oral resection, cervical spine surgery (Logeman, 1998).
Consider Medications as a potention cause or exacerbation for swallowing disorders. Sedative drugs or drugs that cause disorientation or confusion can negatively impact swallowing. Also drugs that cause xerostoma (drying of the mouth) can adversely affect swallowing by delaying the initiation. Saliva is needed to manipulate the bolus and elicit a swallow. Some antipsychotic drugs can lead to extrapyramidal symptoms such as tardive dyskinesia, dystonia, and symptoms that mask Parkinson’s Disease.
2. Interview the patient and any information relevant to swallowing from the patient including history of dysphagia, weight loss, heart burn, reflux, voice changes, etc.
- Weight can give information about the severity of the dysphagia or the effectiveness of a nutritional management plan.
- Heart burn is an indicator of reflux. Reflux can be either Gastroesophageal reflux or Laryngopharyngeal reflux (LPR).
- Abnormal voices such as hoarseness, strained, or breathy vocal quality may represent vocal fold dysfunction, paresis/paralysis.
- Also consider dysarthria as this would mean the patient has a neurological problem
- Nasality- Hypernasality implies impaired palatopharyngeal function; hyponasality implies occlusion of the nasal passages or impaired palatopharyngeal function.
Take note if the patient has had any recent changes in overall health, any history of respiratory infections, any changes to his or her smell, taste, or food intake, any problems with unplanned weight loss or dehydration, or if extended time is needed to consume a meal. Consider the patient’s current nutritional status, if they are receiving alternative means of nutrition such as a nasogastric tube, G-tube, or J-tube.
Questions to ask during the assessment:
Do you have difficulty swallowing? In what way?
Is the swallowng difficulty greater for solids or liquids?
Do you have this sensation without swallowing food?
How long has swallowing difficulty been present?
Can you localize the dysphagia? (where does the food get stuck?)
Has heartburn been associated with your dysphagia?
Is swallowing painful?
Do you get chest pain?
Does food get stuck when you swallow? If so, where?
Do you choke or cough when you swallow?
Is there temperature sensitivity to dysphagia (especially cold)?
Has there been weight loss?
3. A Cranial Nerve Exam of the nerves used in swallowing is used to determine if there is any paresis or paralysis of the muscles used for swallowing.
4. Assess the patient’s volitional cough. A weak volitional cough can be an indicator of vocal fold deficits. Volitional cough is elicited by asking the patient to cough with as much force as possible. An abnormal volitional cough has been described as being either “weak”or as “wet/gurgly.” In one study of 57 patients with bilateral strokes evaluated with video fluroscopy, the majority of aspirators (21 of 25 patients; 84%) were identified by subjective evaluation to have a weak or absent volitional cough (Horner, 1990).
5. Note dentition and overall oral hygiene. Poor oral hygiene is a risk factor for aspiration pneumonia.
6. Assess laryngeal elevation prior to po trials to determine ability to swallow
7. Test Trials- Testing swallowing brings a certain degree of risk for aspiration for the patient. PO trials such as thin liquids, thick liquids, puree, and solids can be used to determine the appropriate consistency. Ice may be a good place to start as it is relatively safe if partially aspirated. The patient may not be appropriate for all types of consistencies, or any. The swallow evaluation may need to be deferred if the patient is not medically stable or awake enough for trials of food.
Risk factors to look at during a bedside swallow evaluation:
- Coughing before, during and after the swallow
- Wet, gurgly vocal quality
- Throat clearing
- Significant fatigue
- Increased secretions
- Multiple swallows per bolus
- Labored breathing
- Poor awareness
- Poor control of secretions
- Infrequent swallowing (less than 1 swallow in five minutes)
After taking all the above information into account, the appropriate diet consistency may be made. There are standardized dysphagia diet levels to help clinicians to place patients on the same diet across facilities.
If symptoms of a pharyngeal stage dysphagia are identified, a more in-depth diagnostic procedure may be warranted. A video swallow study (VFSS; aka modified barium swallow study) is the most frequently used technique to objectively assess the oral and pharyngeal phases of swallowing. This study uses fluoroscopy in video or digitized format to capture the oropharyngeal swallowing process. This study allows the speech pathologist to determine if dysphagia exists, the severity, and aids in behavior or compensatory strategies.
See Dysphagia Compensations for strategies to use during videofluoroscopy.
An individual with any difficulties with the esophageal phase of swallowing should be referred to a gastroenterologist. This includes patients with complaints of globus (feeling of the food stuck in the throat), gastroesophageal reflux, or stomach issues. Speech pathologists should understand symptoms of esophageal dysphagia. Laryngopharyngeal reflux may be a factor if the individual complains that food gets stuck in their throat or reports reflux. A barium swallow study or upper gastrointestinal series can be performed to further evaluate esophageal issues. Speak with your doctor if you are having any difficulties swallowing.
Possible Consequences of Swallowing Problems:
The identification of dysphagia is critical to the management of both physical and emotional risks associated with this disorder. According to the American Speech-Language Hearing Association, dysphagia can result in:
1) aspiration pneumonia-Aspiration may occur if food or liquid passes into the lungs as a result of entering the airway instead of the esophagus. The person who aspirates may be at risk for pneumonia.
2) Weight Loss and/or Malnutrition- This may occur if the person loses appetite due to fatigue or difficulty with eating.
3) Dehydration- Dehydration may occur when the person is unable to swallow enough liquids.
4) Airway obstruction- If a large piece of food gets lodged into the airway, the patient may choke and be unable to breathe.
5) Less enjoyment of eating or drinking. Individuals who had dysphagia resulting from stroke often did not find eating to be enjoyable because of their fears, dependency, and appearance.
6) Embarrassment or isolation in social situations involving eating. These studies suggest that social and family activities that revolve around food and that contribute to richness, vitality, and fullness of life, are often diminished in patients with dysphagia.
“The consequences of dysphagia vary from social isolation to the embarrassment of choking or coughing at mealtime, to physical discomfort, and to potentially life-threatening conditions. Both overt aspiration and silent aspiration may lead to pneumonia, exacerbation of chronic lung disease, or even asphyxiation and death (Robbins, 2002).”
Once the speech-language pathologist (SLP) determines a patient to be positive for dysphagia, they will devise a treatment plan for the patient. Treatment varies greatly depending on the cause, symptoms, and type of swallowing problem. A SLP can recommend the best treatment strategy, but most therapies involve three components.
Modifications to the consistency of foods
- Depending on the type and severity of the swallowing disorder, a specific diet may be recommended. These diets vary from thin liquids, to thick liquids, to soft foods, and to mixed textures.
- Dietary modifications are not always intuitive. For example, swallowing thin liquids requires finer motor skills than thick liquids. Therefore, a diet of thick liquids might be the best strategy for patients with severe dysfunction. However, thickening liquids may not prevent pneumonia.
Strategies to reduce the risk of aspiration
- These strategies often involve various head positions and swallowing techniques intended to reduce the size and duration of airway openings during the swallowing process.
- See dysphagia compensations for more information
- The use of prosthetic devices can restore safe oral functioning.
Exercises to improve swallowing effectiveness
- The focus here is on range of motion and strengthening muscles in the jaw, cheek, lips, tongue, soft palate, and vocal cords. Below is an example of the types of exercises that might be recommended.
SEE DYSPHAGIA TREATMENT FOR MORE INFORMATION
Anand Swaminathan, MD. “eMedicine.com: Pneumonia, Aspiration“.
Logeman, Jerry. (1998).
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Wilkins, T., et al. (2007). The prevalence of dysphagia in primary care patients: a HamesNet Research Network study. The Journal of the American Board of Family Medicine, 20(2), 144-150.
Spieker, M.R. (2000). Evaluating dysphagia. American Family Physician, 61, 3639-3648.
Robbins, J., & Barczi, S. (2003). Disorders of swallowing. In W.R. Hazzard, J.P. Blass, J.B. Halter, et al. Principles of Geriatric Medicine and Gerontology (5th ed., pp. 1193- 1212). New York: McGraw-Hill, Inc.
European Study Group for Diagnosis and Therapy of Dysphagia and Globus (EGDG), & Dysphagia Working Group (RCSLT), Recommendations for Pre and Post Registration Dysphagia Education and Training 1999.
Hare, S., Tam, T., Ibarra, M., & Edwards, W. Malnutrition in hospitalized elderly in the capital health region, Grey Nuns Community Hospital and Health Centre. Edmonton, Alberta.
Horner, J, Massey, EW, Brazer, SR Aspiration in bilateral stroke patients.Neurology 1990;40,1686-1688
Palmer, J.B., Drennan, J.C., & Baba, M. (2000). Evaluation and treatment of swallowing impairments. American Family Physician, 61, 2453-2462.
Robbins, J. (2002). The current state of clinical geriatric dysphagia research. Journal of Rehabilitative Research and Development, 39(4), vii-ix.
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