Eamonn Brady MPSI provides a clinical overview of dysphagia, including causes, prognosis and therapies

ysphagia’ is a medical term that is used to refer to difficulties with swallowing. Some people with dysphagia have problems swallowing certain foods or liquids, while others are completely unable to swallow.

Dysphagia usually arises as a complication of another health condition, such as a stroke, throat and mouth cancer or gastro-oesophageal reflux disease (GORD), which is a condition where stomach acid leaks back up into the oesophagus. The oesophagus is the tube that connects the stomach to the throat. 

Cases of patients presenting with unexplained pneumonia, dysphagia and progressive weight loss have been increasing in practice. Many are thought to be linked to swallowing disorders, which have been under-diagnosed in practice.

Types of dysphagia

There are two types of dysphagia:

Oropharyngeal or high dysphagia. This is where the difficulties in swallowing are due to problems with the mouth or throat. 

Esophageal or low dysphagia. This is where the difficulties in swallowing are due to problems with the oesophagus.

Low dysphagia is often caused by a blockage in or irritation to the oesophagus, and can often be treated with surgery.

High dysphagia is often caused by underlying problems with the nerves and muscles that help control the swallowing process. High dysphagia can be more challenging to treat than low dysphagia.

How common is dysphagia?

Dysphagia can be a common condition among people with certain related health conditions. It is estimated that 30-to-40 per cent of elderly people staying in nursing homes have some degree of dysphagia. 

Dysphagia is also a common complication of strokes, occurring in an estimated one in every two cases.

Prognosis

Aside from the obvious risk of malnutrition and dehydration, difficulties with the swallowing reflex mean that there is a chance that small particles of food can drop down into the lungs. That can trigger a serious and possibly fatal lung infection (aspiration pneumonia). The recommended treatment for dysphagia will depend on the underlying cause of the condition. 

However, some possible treatments include:

Physical therapy. 

Diet modification. 

Surgery. 

The use of feeding tubes.

Symptoms of dysphagia 

The symptoms of dysphagia include:

Not being able to swallow. 

Pain while swallowing. 

Bringing food back up. 

Coughing or choking when eating. 

Coughing or gagging when swallowing. 

A sensation that food is stuck in your throat or chest. 

Unexplained weight loss. 

Developing repeated and frequent lung infections (pneumonia).

Some symptoms of dysphagia can be seen or heard and are usually detected by the nurse. Symptoms may occur at any time in the act of swallowing. In the oral preparatory phase, symptoms may include drooling, failure to drink from a cup, failure to chew, or intolerance of textures. 

In the oral phase, symptoms may include stasis in the oral cavity or pocketing of food. In the pharyngeal phase, symptoms may include gagging, congestion, coughing, audible breathing and a gurgly or hoarse voice. In the oesophageal phase, symptoms may include vomiting, reflux or pain.

Causes of dysphagia 

Neurological causes

Brain damage and damage to the nervous system can interfere with the nerves that are responsible for triggering and regulating the swallowing reflex. This can lead to dysphagia.

Some neurological causes of dysphagia include:

Stroke. 

Cerebral palsy. 

Parkinson’s disease. 

Multiple sclerosis. 

Motor neurone disease.

Obstruction

Health conditions that cause an obstruction in or a narrowing of the throat and oesophagus can make swallowing difficult. 

Some causes of obstruction and narrowing include:

Mouth or lung cancer. 

Cleft lip and palate. 

Radiotherapy (radiation can cause the development of scar tissue, which can narrow the passageway in the throat and oesophagus). 

Gastro-oesophageal reflux disease (GORD) (stomach acid can cause scar tissue to develop).

Infections, such as tuberculosis or herpes simplex, that lead to the inflammation of the oesophagus (esophagitis).

Muscular conditions

Any health condition that affects the muscles that are used to push food down through the oesophagus and into the stomach can cause dysphagia. Two examples of muscular conditions that are associated with dysphagia are:

Scleroderma. The immune system attacks healthy tissue, leading to a stiffening of the throat and oesophagus muscles. 

Achalasia. The muscles in the oesophagus become too stiff to allow food or liquid to enter the stomach.

As a natural consequence of ageing, the muscles that are used in swallowing can become weaker. This may explain why dysphagia is a relatively widespread condition among elderly people. Dysphagia should not simply be accepted as part of growing older, because treatment is available to help those with age-related dysphagia.

Dry mouth

A history of dry mouth or eyes may indicate inadequate salivary production. In such cases it is particularly important to obtain a detailed review of medications. Anticholinergics, antihistamines, and certain antihypertensive agents can reduce salivary flow.

Diagnosing dysphagia 

In diagnosing dysphagia, the aim is to determine the exact location of the swallowing problem (whether it is ‘high’ or ‘low’ dysphagia) and to assess how the ability to swallow has been affected. There are a number of ways that this can be done, which are explained below.

Recent medical history

Knowing how long the patient has been experiencing dysphagia for, whether or not dysphagia has affected ability to swallow solids, liquids or both, and whether there is weight loss will help make the diagnosis.

Water-swallow test

A doctor may carry out a water-swallow test, which can provide a good initial assessment of swallowing abilities. The patient is given 150ml of water and asked to swallow it as quickly as possible. The doctor will record how long it takes you to drink all the water and the number of swallows that were required.

The doctor may also carry out a variation of the water-swallow test, where the patient is asked to swallow a soft piece of pudding or fruit.

Barium swallow test

If a GP suspects that a patient has dysphagia, they may refer the patient to an ear, nose and throat (ENT) clinic for further testing.

The barium swallow test is one of the most effective ways of assessing a person’s swallowing, and locating exactly where the problems are occurring. The test can often identify blockages or problems with the muscles that are used during swallowing.

As part of the test, the patient is asked to drink some barium solution. Barium is a non-toxic chemical that is widely used for testing purposes because it shows up on an x-ray. 

During the barium swallow test, a special video camera will be used to record the patient swallowing (or trying to swallow) the barium solution. The footage will be studied to check for problems.

Endoscopy

An endoscopy is a test that uses a small, flexible camera called an endoscope. The endoscope will be passed down the throat and into the oesophagus. The endoscope can often detect the presence of cancerous tumours, or scar tissue that has been caused by GORD.

Treating dysphagia 

Dysphagia is diagnosed and treated by a multidisciplinary team, including a radiologist, speech therapist, dietician and nurse.

Treating oropharyngeal or ‘high’ dysphagia

It can be difficult to achieve a complete cure for high dysphagia because the underlying neurological problems cannot usually be corrected using medication or surgery. The exception to this is dysphagia caused by Parkinson’s disease. While Parkinson’s disease cannot be cured, the symptoms of dysphagia can be controlled using medication. 

Excluding dysphagia that is caused by Parkinson’s disease, there are three main treatment options for ‘high’ dysphagia:

Swallowing therapy, where a speech and language therapist (SLT) will teach the patient to ‘re-learn’ how to swallow, or find a new way of swallowing. 

Dietary changes, such as eating softer foods. 

Feeding tubes, which can be used to provide nutrition while the patient is trying to recover the ability to swallow.

Swallowing therapy

The SLT may be able to teach the patient exercises that can stimulate the nerves that are used to trigger the swallowing reflex, and strengthen the muscles that are used during swallowing.

There are also a number of physical techniques that can be used to make swallowing easier.

Tilting the head back and placing the bolus posteriorly on the stronger side of the mouth can counterbalance reduced oral mobility. 

Bending the neck forward can offset delayed pharyngeal contraction by assisting laryngeal elevation and closure. 

Turning the head to the weaker side while tilting it to the stronger side can facilitate directing and propelling of the bolus, and can help compensate for unilateral pharyngeal dysfunction. 

Oral motor exercises can strengthen the lip and tongue and control drooling while assisting bolus formation and propulsion. 

Deliberate multiple swallows help clear pooling in the pharynx. 

Dietary modifications may also improve swallowing and help avoid aspiration. Some patients are more tolerant of solid, soft, or liquid consistencies. 

For patients with intolerance to liquids, for example, commercially available food additives that thicken liquids may be helpful, since increasing bolus viscosity can improve swallowing function, ie, Nutilis, Thick & Easy, Swalloweze. Other patients benefit from a reduction in the volume of their mouthfuls, or an alternation of solid and liquid boluses, which can facilitate transfer. In some cases, feeding with a particular implement, such as a cup or spoon, may improve swallowing (avoid straws).

For patients whose dysphagia is related to neurological dysfunction, administering meals during times of maximal attentiveness may be beneficial. Simple remedies should not be overlooked. As an example, partially dentulous elderly patients who have difficulty masticating may benefit from prosthetic teeth.

Dietary changes

The patient may be referred to a dietician, who will advise the patient about making changes to their diet, such as incorporating food and liquids that are easier to swallow while ensuring that they receive a healthy, balanced diet.

Mashed potatoes are a good source of carbohydrates. Scrambled eggs and cheese are high in protein and calcium. 

Two main concerns in the dietary management of the dysphagic patient are to maintain adequate nutrition and to ensure safety during oral feeding. The ultimate goal is to train the patient to select the proper foods and use the recommended swallowing techniques.

Standard hospital diets are served with liquids. Dysphagic patients require modifications of these diets. Kitchen and nursing staff must remove from standard diet trays solid foods and liquids that pose swallowing hazards. For example, thin liquids, such as water, juices and coffee are often the most difficult to swallow. Some patients have difficulty manipulating, swallowing and clearing thick liquid texture such as milk-shakes and honey. Other patients may have problems with foods that are dry, chewy, crispy or stringy.

Taste

Strong flavours such as sweet, spicy, sour or salty tastes may stimulate salivation, swallowing or mastication. Bland flavours should be avoided.

Temperature

Food should be served at hot or cold temperatures rather than tepid or at room temperature to stimulate the swallowing response. Specific recommendations for cold foods include ice chips and ice cream, if tolerated, to provide sensory input. Exceptions, however, must be made for patients with decreased oral sensation. For those patients, food should be served tepid or at room temperature to minimise the burning or numbing of oral structures.

Texture

Liquids should be thick; foods that form a bolus in the mouth are easier to swallow. Patients should avoid foods that are crumbly or fall apart in the mouth. Density and shape are important as well. Most researchers agree that jelly slips down easily. Apple sauce may be difficult, as it does not maintain a cohesive bolus in the mouth. Foods such as canned fruit, jelly and ice chips may be easier for some patients to manage. The choice of such foods is an individual decision based on the patient’s capabilities.

Consistency

Easy to chew does not mean easy to swallow. A dysphagia diet can progress from the most to least restrictive foods. Semi-solids such as soft peaches, oatmeal and thickened pureed fruits are easy to swallow, since they hold their shape in the mouth and stimulate swallowing. Liquids are usually more difficult to swallow than solids, since they do not provide as strong a stimulus as solid foods. Water is usually the most difficult to control; it runs into corners and down the throat. Liquids such as gravy and juices can be used to moisten dry foods. All researchers agree that liquids and foods should be presented separately. Never use a fluid to ‘wash the bolus down’. Two different consistencies can send confusing stimuli.

Mucus production 

Problems with excess and inadequate saliva production should be addressed. The elderly, for example, show decreased salivary production. All researchers agree that milk products tend to form excess mucus that can be difficult to clear and swallow. Chocolate may stimulate secretions in some patients. Yoghurt, cheese and cottage cheese can be added to the diet instead of milk if there is a problem with milk increasing mucous production.

Feeding tubes

Feeding tubes may be required in severe cases of dysphagia that put a patient at risk of malnutrition and dehydration.

There are two types of feeding tubes:

Nasogastric tube, a tube that is passed down the nose and into the stomach; and 

Percutaneous endoscopic gastrostomy (PEG) tube, a tube that is surgically implanted directly into the stomach, which passes through a small incision on the surface of the stomach or abdomen.

Nasogastric tubes are designed for short-term use and last for 10-to-28 days before they need to be replaced.

PEG tubes are designed for long-term use and last for up to six months before they need to be replaced.

Most people with dysphagia prefer to use a PEG tube because the equipment can be easily hidden under clothing. However, PEG tubes do carry a greater risk of complications than nasogastric tubes. Minor complications of PEG tubes include:

Tube displacement. 

Skin infection. 

Tube blockage. 

Tube leakage.

Major complications of PEG tubes include:

Internal bleeding. 

Infection.

There is also some evidence that people who use PEG tubes find it more difficult to resume normal feeding compared with those who use nasogastric tubes. This could be because the added convenience offered by PEG tubes means that people are less willing to participate in swallowing exercises and dietary changes than people who use nasogastric tubes.

Treating oesophageal or ‘low’ dysphagia

Surgery

Cases of low dysphagia can usually be treated using surgery. Dilation is a widely-used technique in cases of obstruction. It involves placing a small balloon inside the oesophagus. The balloon is inflated, which gradually widens the oesophagus, and then the balloon is deflated and removed.

Botulinum toxin (better known as Botox)

Botulinum toxin can be used to treat achalasia (a type of dysphagia where the muscles in the oesophagus become too stiff to allow food and liquid to enter the stomach). Botulinum toxin is a powerful poison that is safe to use in minute doses. The toxin can be used to paralyse the over-stiff muscles that are preventing food from reaching the stomach.

Complications of dysphagia 

Aspiration pneumonia is a lung infection that is triggered when a small piece of food enters the lungs. People with oropharyngeal or ‘high’ dysphagia are particularly vulnerable to aspiration pneumonia because their impaired swallowing reflexes mean that their larynx does not close during swallowing, so their lungs are not protected. When the airway is unprotected and foreign material is aspirated into the lungs, the person is at risk for development of pulmonary infection and aspiration pneumonia, the fifth-leading overall cause of mortality in the US and the fourth-most frequent cause of death in the elderly. The more liquid or fluid the substance, the more likely it will be aspirated and travel further into the respiratory system. 

The symptoms of aspiration pneumonia include:

Fever. 

Fatigue. 

Chest pain. 

Shortness of breath. 

Blue skin (cyanosis) due to a lack of oxygen. 

Wheezing.

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References on request.

Written by Eamonn Brady (Pharmacist). Whelehans Pharmacies, 38 Pearse St and Clonmore, Mullingar. Tel 04493 34591 (Pearse St) or 04493 10266 (Clonmore). http://www.whelehans.ie