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Research Tuesday : Dysphagia Article Review

December 10, 2013, by Rinki Varindani, category DYSPHAGIA, EVIDENCE BASED PRACTICE, MEDICAL SLP, RESEARCH

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On the second Tuesday of each month, SLP bloggers around the world blog about research related to the field of Speech Language Pathology. I found Research Tuesday be an exciting initiative and decided to start participating in it this month. I aim for this to become a monthly routine. Rachel Wynn, a fellow SLP, publishes a monthly summary of Research Tuesday blog posts on her website. You can read more about it here.

I decided to blog about a review article I read that discusses the diagnosis and management of oropharyngeal dysphagia in the elderly. It also highlights the need to recognize and manage the nutritional and respiratory complications associated with dysphagia in this population. I chose this article in particular since it provides a detailed review about oropharyngeal dysphagia in the elderly, which comprises majority of the caseload I work with (and most Medical SLPs deal with) on a daily basis. The original article is about 13 pages long, but I have summarized it as best as I could. I hope you find it helpful.

Title:
Diagnosis and Management of Oropharyngeal Dysphagia and Its Nutritional and Respiratory Complications in the Elderly

Published in Gastroenterology Research and Practice, Volume 2011 (2011), Article ID 818979, 13 pages

Link to Original Article

1. Definition and Prevalence

Dysphagia refers to difficulty or discomfort during the progression of the alimentary bolus from the mouth to the stomach. From an anatomical standpoint, dysphagia may result from oropharyngeal or esophageal dysfunction and from a pathophysiological standpoint, from structure-related or functional causes.

Oropharyngeal functional dysphagia affects more than 30% of patients who have had a cerebrovascular accident; 52%–82% of patients with Parkinson’s disease; 84% of patients with Alzheimer’s disease, up to 40% adults aged 65 years and older, and more than 60% of elderly institutionalized patients. This makes oropharyngeal dysphagia a serious disorder in the elderly, which can have an enormous impact on their functional capacity, health and quality of life.

2. Pathophysiology

Dysphagia may be caused by structural alterations that may impair bolus progression such as tumors, neck osteophytes, post-surgical esophageal stenosis and Zenker’s diverticulum. It may also be a side effect in patients with head and neck cancer undergoing radiotherapy. However, oropharyngeal dysphagia in the elderly is more frequently a functional disorder affecting the oropharyngeal swallow response.

The article states that the delayed swallow response in the elderly may be attributed to an impairment of sensations, a decrease in the number of neurons in the brain or a delay in the synaptic conduction of the afferent inputs to the central nervous system caused by aging, neurodegenerative diseases and/or stroke. Conditions such as delirium, confusion, dementia and side effects of certain drugs can also impair the swallow response in older patients.

Transfer of the bolus from mouth through the pharynx is mainly caused by the squeezing action of the tongue. The authors of the article have stated that older adults present with lingual weakness, a finding that has been related to sarcopenia (gradual loss of muscle mass with age) of the head and neck musculature and frailty. Their research shows that older adults with oropharyngeal dysphagia present with impaired tongue propulsion forces (<0.14 mJ) and slower bolus velocity (<10 cms/s) compared to young healthy adults who have stronger measures of bolus propulsion (>0.33 mJ) and high bolus velocity (>35 cm/s).

Therefore, the authors conclude that dysphagia in the elderly is associated with impairment in efficacy and safety of swallow caused by weak tongue propulsion  and a delayed swallow response

3. Diagnosis

The article states that there is a big discrepancy concerning the prevalence, morbidity, mortality, and costs caused by nutritional and respiratory complications of dysphagia and the resources dedicated to patients with dysphagia. It goes on to stress that the diagnosis of oropharyngeal dysphagia needs to be a multidisciplinary approach, further describing the members of the multidisciplinary dysphagia team and what their goals should be for the patient. The involvement of the patient’s family in the diagnostic and therapeutic process is of critical importance.

Once a diagnosis of functional oropharyngeal dysphagia has been established, the goal of the diagnostic program is to evaluate two deglutition-defining characteristics as per the authors of the article:

  • efficacy: the patient’s ability to ingest all the calories and water he or she needs to remain adequately nourished and hydrated;
  • safety: the patient’s ability to ingest all needed calories and water with no respiratory complications

To assess both these characteristics of swallowing, two groups of diagnostic methods are available:

1. Clinical methods (screening and bedside swallow evaluation)

Clinical methods for oropharyngeal dysphagia include screening, which should be low risk, quick, low cost and must aim at selecting the highest risk patients who require further assessment. Current methods for clinical screening of dysphagia are:

  • The water swallow test
  • 3-oz water test developed in the Burke Rehabilitation Center
  • The timed swallow test and
  • The standardized bedside swallow assessment (SBSA)

 The authors state that these clinical bedside methods detect dysphagia with differing diagnostic accuracy, have varying degrees of sensitivity and specificity in detecting aspiration and may place the patient at risk for aspiration. For these reasons, their team developed a method of swallow screening, which they have shown to be safer and more accurate, described as the V-VST (volume-viscosity swallow test.) The test basically involves using a series of 5–20 mL nectar, liquid and pudding boluses, sequentially administered in a progression of increasing difficulty to the patient. You can read about it in further detail in the original article.

2. Specific complementary studies (VFSS and FEES)

The article states that Videofluoroscopy (Modified Barium Swallow Study) is the gold standard to study the oral and pharyngeal mechanisms of dysphagia. If no VFS is available, fiberoptic endoscopic evaluation of swallowing (FEES) may be used instead. Per the research and findings of the authors, the major videofluoroscopic signs of impaired efficacy and impaired safety during the oral and pharyngeal stages of swallowing have been described in the article.

4. Complications of Oropharyngeal Dysphagia

The article states that oropharyngeal dysphagia may give rise to two groups of clinically relevant complications in older people:

  • Malnutrition and/or dehydration caused by a decrease in the efficacy of swallowing, present in up to 25%–75% patients with dysphagia;
  • Choking and aspiration caused by a decrease in swallow safety, which results in pneumonia in 50% of cases, with an associated mortality of up to 50%.

A recent 10-year review found a 93.5% increase in the number of hospitalized older patients diagnosed with aspiration pneumonia, while other types of pneumonia in the elderly decreased. These complications have been summarized below.

1. Nutritional Complications: Malnutrition/Dehydration

Impairment in swallowing efficacy may reduce oral intake and lead to malnutrition, unless nutritional status is monitored and specific strategies are introduced to enhance caloric intake. The article states that up to 30% of neurological patients and up to 55% of frail older patients with dysphagia present or are at risk of malnutrition with a strong relationship between severity of dysphagia and incidence of malnutrition.

Dehydration is also a frequent complication of dysphagia in elderly patients with oropharyngeal dysphagia and is considered to be a significant cause of mortality in the elderly. The article thus goes on to stress that all older patients with oropharyngeal dysphagia need a detailed nutritional assessment to detect those who may be at nutritional risk, so that appropriate management strategies can be put into place.

2. Respiratory Complications: Aspiration Pneumonia

The risk of Aspiration Pneumonia (AP) is higher in older patients because of the high incidence of dysphagia. The authors’ findings show that in elderly nursing home residents with oropharyngeal dysphagia, AP occurs in 43%–50% during the first year, with a mortality of up to 45%. The authors go on to describe findings of their own study indicating that oropharyngeal dysphagia is a highly prevalent clinical finding and an indicator of disease severity in older patients with pneumonia.

The article goes on to discuss several risk factors (such as smoking, decreased immunity, dry mouth, antibiotics etc.) which cause dysphagia and contribute to oropharyngeal bacterial colonization, thus playing a role in the pathogenesis of Aspiration Pneumonia in the elderly.

5. Treatment of Dysphagia

The treatment of dysphagia in older patients varies greatly, contributing to the controversy surrounding the effect of swallowing therapy in preventing malnutrition and Aspiration Pneumonia (AP). The review found that there is insufficient data to determine the effectiveness of treatment methods for dysphagia in preventing AP in older adults and cites reasons for the same. Conversely, there are also some studies which find that treatment of dysphagia is cost-effective and it positively correlates with a reduction in AP rates.

Dysphagia therapy provided by an SLP aims at improving the speed, strength and range of movement (ROM) of muscles involved in the swallow response and at modifying the mechanics of swallow to improve bolus transfer and avoid/minimize aspiration. Here is a line from the article that really stood out for me;

‘’The management of dysphagia is not an exact science, but a combination of clinical expertise and the best available evidence-based medicine.’’

The authors group the management strategies for oropharyngeal dysphagia in older patients into six major categories, which may be simultaneously applied. I have summarized them briefly below:

1. Postural strategies, body and head positions:

The review suggests that anterior neck flexion (chin tuck) protects the airway, posterior flexion (chin raise) facilitates gravitational pharyngeal drainage and improves oral transit velocity; head rotation (head turn maneuver) towards the paralyzed pharyngeal side directs food to the healthy side, increases pharyngeal transit efficacy and facilitates UES aperture, whereas head tilt to the stronger side prior to the swallow directs the bolus down to the stronger side by utilizing the effects of gravity.

2. Changes in bolus volume and viscosity:

Studies indicate that reductions in bolus volume and enhancement of bolus viscosity can significantly improve safety and minimize the risks of penetration/aspiration. The prevalence of penetration/aspiration is found to be maximal with water and thin fluids and decreases with nectar and pudding thick boluses. Thus, dietary modifications such as thickening of liquids can reduce the risk of AP in affected patients and help in ensuring that these patients remain adequately hydrated and nourished.

3. Neuromuscular praxis:

The goal here is to improve the physiology of swallowing.

  • Progressive resistance lingual exercises have proven to correspond with increased pressure generation during swallowing in stroke patients, thus showing significant improvement in swallowing function and dietary intake.
  • Cervical flexion exercises (Shaker exercise) have shown to improve hyoid and laryngeal elevation, increase UES aperture, reduce pharyngeal residue and improve dysphagia symptoms in patients with neurogenic dysphagia.
  • The tongue-holding or Masako maneuver is supposed to compensate for the reduction in tongue base-pharyngeal wall contact in swallowing, thus contributing to an increased anterior movement of the posterior pharyngeal wall during swallowing.
  • Another motor treatment for improving muscle strength is neuromuscular electrostimulation (NMES). Several studies have been published with controversial therapy outcome using NMES. However, the article states that meta-analysis shows a small but significant treatment effect for transcutaneous NMES on patients with dysphagia.

Details of these studies may be found in the original article, for those interested.

4. Specific swallow maneuvers:

The article describes the following swallowing maneuvers that compensate for specific biomechanical alterations and may help in improving swallow function/safety:

  • Supraglottic and Super Supraglottic Swallow.
  • Effortful, Forceful, or Hard Swallow
  • Double Deglutition
  • Mendelsohn Maneuver

5. Surgical/Drug-based Management of UES Disorders:

Impaired neural UES relaxation may be observed in spastic neurological diseases such as Parkinson’s disease or brain injury. These patients may be managed surgically with a cricopharyngeal myotomy or via injection of botulinum toxin in the sphincter as a therapeutic alternative.

6. Sensorial enhancement strategies: 

The review found that oral sensorial enhancement strategies are particularly useful in patients with apraxia or impaired oral sensitivity (very common in older patients). The aim of these strategies is the initiation or acceleration of the oropharyngeal swallow response. Most sensorial enhancement strategies include a mechanical stimulation of the tongue, bolus modifications (volume, temperature, and taste), or a mechanical stimulation of the pharyngeal pillars. Acid flavors such as lemon or lime and cold substances such as ice cream or ice are found to trigger the mechanism of deglutition and have proven to be effective in dysphagia therapy.

7. Pharmacology of Swallow Response in Older People:

Several drugs, most centrally acting, can elicit oropharyngeal dysphagia in older people. The article discusses some of these. It also states that several types of pharmacological and mechanical agents may help in improving the swallowing reflex and cough-reflex sensitivity. The development of physical or drug-based strategies to accelerate the swallow response is a relevant field of research for the management of dysphagia.

8. Percutaneous Endoscopic Gastrostomy:

The article discusses specific groups of patients with dysphagia so severe that they cannot be treated despite using rehabilitation techniques. In these patients, VFS findings may objectively demonstrate the inability to eat orally and the need to perform a percutaneous endoscopic gastrostomy (PEG). However, it is important to note that there is little evidence that nonoral feeding reduces the risk of aspiration. For long-term nutritional support, PEG should be preferred to nasogastric tubes since it is associated with less treatment failure, better nutritional status and may also be more convenient for the patient. For many patients requiring a PEG placement, a small percentage of food may still be safely administered through the oral route.

Conclusion

Identification of functional oropharyngeal dysphagia as a major neurological and geriatric syndrome will cause many changes in the provision of medical and social services in the near future. Education of health professionals on diagnosis and treatment of dysphagia and its’ complications, early diagnosis, development of specific complementary explorations in the clinical setting, improvement in therapeutic strategies to avoid aspiration, and research into its pathophysiology are the cornerstones to allow maximal recovery for older patients with functional oropharyngeal dysphagia.

I found this article to be a comprehensive and informative review of oropharyngeal dysphagia in the elderly. The findings and references gave me a chance to explore a number of other studies and relevant research as well. I sincerely hope you found my summary helpful. Once again, you can find the original article here.

Until next time… :)

 


 

So, what do you think ?