Dysphagia

The term dysphagia, a Greek word that means disordered eating, typically refers to difficulty in eating as a result of disruption in the swallowing process. Dysphagia can be a serious health threat because of the risk of aspiration pneumonia, malnutrition, dehydration, weight loss, and airway obstruction, and it exerts a large influence on the outcome of rehabilitation (eg, length of hospital stay, mortality/morbidity).[2] (See Prognosis and Treatment.)

Dysphagia can be secondary to defects in any of the 3 phases of swallowing, which are as follows[3] :

• Oral phase: Which involves the oral preparatory phase and the oral transit phase

• Pharyngeal phase

• Esophageal phase

A number of etiologies have been attributed to dysphagia in populations with neurologic and nonneurologic conditions. (See Pathophysiology and Etiology.)

Dysphagia should be differentiated from disorders that prevent transfer of food to the mouth or beyond the stomach but that are not characterized by difficulty swallowing. For example, feeding disorder, which is the inability to get food to the mouth, and gastric outlet obstruction, which is the inability of food to pass from the stomach into the small intestine, are not types of dysphagia. On average, 10 million Americans are evaluated for swallowing disorders annually. (See Epidemiology and DDx.)

Advances have been made in the treatment of swallowing disorders, especially with regard to dysphagia-related malnutrition, and with the available tests and management options for swallowing disorders, the prognosis for patients with dysphagia has improved. (See Prognosis, Clinical Presentation, Workup, and Treatment.)

An understanding of the anatomy and physiology of the areas of the body affected by dysphagia is of paramount importance in the diagnosis and management of swallowing disorders (see the image below). Early involvement of specialists such as nutritionists, gastroenterologists, general surgeons, speech-language therapists, and ear, nose, and throat (ENT) surgeons offers a good prognosis for the management of swallowing disorders. (See Treatment.)

Lateral projection of the videoprint of a videographic swallowing study shows the epiglottis (E), pyriform sinuses (P), tongue (Tg), trachea (Tr), and vallecula (V).

Pediatric patients

Certain factors make dysphagia in children unique. Successful oral feeding and growth in infants and children depend not only on functional deglutition but also on a broad range of neurodevelopmental skills involving sensory systems, cognition, communication, and gross and fine motor behaviors.[4, 5]

Prematurity by itself and neurologic impairment (eg, cerebral palsy) are common causes of dysphagia in young patients. Children with cerebral palsy typically manage solid boluses more easily than they do liquid boluses and manage small liquid boluses more easily than large liquid boluses.

Congenital structural lesions (eg, choanal atresia, cleft lip and palate, craniofacial syndromes) can interfere with normal anatomic transport of a bolus.[6] Prosthetic devices or adaptive feeding equipment may be necessary.

Gastroesophageal reflux disease (GERD) is a common problem in children. Choking, food refusal, and food "getting stuck" are nonspecific symptoms that may arise because of reflux and esophagitis.

Childhood achalasia appears to be more common in boys than in girls. Regurgitation of food and dysphagia are the most common symptoms. In about 18% of patients, symptoms begin during infancy.

Management of pediatric dysphagia requires a special approach. Cognitive, developmental, and behavioral issues can affect the treatment options. Treatment does not necessarily imply feeding therapy. Tone abnormalities, postural control, adverse behavior, and primitive reflexes should be managed. Hypoxemia can occur while a child with dysphagia eats, so pulse oximetry during mealtime can be useful.[7]

Geriatric patients

The prevalence of dysphagia increases with age, making dysphagia is a major health-care problem in elderly patients. Normal aging alters some aspects of the swallowing function; problems include increased oral and pharyngeal transit times, poor bolus control and coordination, increased magnitude and duration of pharyngeal pressures, and increased incidence of pharyngeal residue after swallowing.[8]

Other factors, such as the following, can cause a predisposition to dysphagia or can aggravate the condition:

• Poor dentition

• Atrophy of the tongue and alveolar ridge

• Diminished taste and smell sensitivity

• Decreased muscle tone

• Increased ligamentous laxity

• Limited laryngeal elevation

Deglutition is the act of swallowing, which allows a food or liquid bolus to be transported from the mouth to the pharynx and esophagus, through which it enters the stomach. Normal deglutition is a smooth, coordinated process that involves a complex series of voluntary and involuntary neuromuscular contractions and typically is divided into distinct phases: oral, pharyngeal, and esophageal. Each stage facilitates a specific function; if the stages are impaired by a pathologic condition, specific symptoms may result.

The process of swallowing is organized with sensory input from receptors in the base of the tongue, as well as in the soft palate, faucial arches, tonsils, and posterior pharyngeal wall; this input is transmitted to the swallowing center, located within the pontine reticular system, through the facial (VII), glossopharyngeal (IX), and vagus (X) cranial nerves.

Information from the swallowing center then is conveyed back to the muscles that help in swallowing through trigeminal (V), facial (VII), glossopharyngeal (IX), vagus (X), and hypoglossal (XII) cranial nerves, with the trigeminal, hypoglossal, and nucleus ambiguus constituting the efferent levels.

The act of swallowing usually interrupts the expiratory phase of ventilation, while the completion of expiration occurs when swallowing ends. In situations in which the swallowing is initiated during the inspiratory phase of ventilation, a brief expiration ensues after the completion of swallowing.

Oral phase

The oral phase of swallowing is divided into the following 2 parts:

• Oral preparatory phase: The processing of the bolus to render it swallowable

• Oral propulsive (or transit) phase: The propelling of food from the oral cavity into the oropharynx

With single swallows of liquid, the entire sequence lasts about 1 second. For swallows of solid foods, a delay of 5-10 seconds may elapse while the bolus accumulates in the oropharynx.

Oral preparatory phase

The process begins with contractions of the tongue and striated muscles of mastication. The muscles work in a coordinated fashion to mix the food bolus with saliva, with the taste, temperature, touch, and proprioception senses required to form a bolus of the right size and consistency. (See image below.)

Oral preparatory phase of normal swallowing.

Oral propulsive phase

This segment of the swallowing process involves manipulation of the bolus formed in the preparatory stage in the central portion of the tongue. The bolus is then pushed toward the pharynx posteriorly with a sequential anterior-to-posterior tongue elevation in order to trigger the swallowing reflex as the bolus enters the pharyngeal phase.

This process requires that a labial seal be maintained to prevent food from leaking from the mouth and that there be buccal musculature tension to prevent food from getting into the recess between the mandible and cheek. (See the image below.)

Oral propulsive phase of normal swallowing.

Pharyngeal phase

The pharyngeal phase is of particular importance, because without intact laryngeal protective mechanisms, aspiration (the passage of food or liquid through the vocal folds) is most likely to occur during this phase. This phase involves a rapid sequence of overlapping events. The soft palate rises, the hyoid bone and larynx move upward and forward, the vocal folds move to the midline, the epiglottis folds backward to protect the airway, and the tongue pushes backward and downward into the pharynx to propel the bolus downward.[9] The tongue is assisted by the pharyngeal walls, which move inward with a progressive wave of contraction from top to bottom.

The upper esophageal sphincter relaxes during the pharyngeal phase of swallowing and is pulled open by the forward movement of the hyoid bone and larynx. This sphincter closes after passage of the food, and the pharyngeal structures then return to the reference position. (See the image below.)

Pharyngeal phase of normal swallowing.

The pharyngeal phase of swallowing is involuntary and totally reflexive, so no pharyngeal activity occurs until the swallowing reflex is triggered. This swallowing reflex lasts approximately 1 second and involves the motor and sensory tracts from cranial nerves IX (glossopharyngeal) and X (vagus).

Esophageal phase

In the esophageal phase, the bolus is propelled downward by a peristaltic movement. The lower esophageal sphincter relaxes at initiation of the swallow, and this relaxation persists until the food bolus has been propelled into the stomach. Unlike the upper esophageal sphincter, the lower sphincter is not pulled open by extrinsic musculature. Rather, it closes after the bolus enters the stomach, thereby preventing gastroesophageal reflux. (See the image below.)

Esophageal phase of normal swallowing.

The medulla controls this involuntary swallowing reflex, although voluntary swallowing may be initiated by the cerebral cortex.

An interval of 8-20 seconds may be required for contractions to drive the bolus into the stomach.

Patient education

For patient education information, see the Cancer Center, as well as Cancer of the Mouth and Throat.

Aspiration is a term referring to the passive entry of any food item into the trachea (eg, during inhalation), although the word often is used to denote any entry of a bolus into the trachea in any manner

Penetration refers to the active entry of any food item into the trachea (eg, during swallowing), although the term often is used to denote the entry of any bolus into the laryngeal vestibule

A lesion in the cerebral cortex or the brainstem can cause swallowing disorders as a result of the following:

• Decrease in range of motion (ROM) of muscles of mastication and bolus propulsion, especially those responsible for buccal, labial, and lingual strength and the cricopharyngeus

• Decreased sensation

• Delayed or absent pharyngeal swallowing and reductions in pharyngeal peristalsis[10]

• Delayed or absent laryngeal adduction and elevation

The locations of specific lesions, however, do not show correlation with findings on computed tomography (CT) or magnetic resonance imaging (MRI) scans.

Disorders of swallowing may be categorized according to the swallowing phase affected. A number of dysphagic problems can be identified during each phase of deglutition.

Oral-phase disorders

Pocketing of food in the mouth, circumoral leakage, and early pharyngeal spill can occur with weakness and poor coordination of the lips, cheeks, and tongue. Weak posterior tongue can lead to abnormal tongue thrusting.

Aspiration of food or drink, especially during inhalation, can occur before pharyngeal swallowing due to premature pharyngeal spillage.

Changes in mental status with cognitive deficits also may affect the initiation of swallowing, increasing the tendency to pocket food in the lateral sulci and leading to possible aspiration.

Logemann's Manual for the Videofluorographic Study of Swallowing cites the following oral-phase swallowing symptoms and disorders[11] :

• Inability to hold food in the mouth anteriorly due to reduced lip closure

• Inability to form a bolus or residue on the floor of the mouth due to reduced range of tongue motion or coordination

• Inability to hold a bolus due to reduced tongue shaping and coordination

• Inability to align teeth due to reduced mandibular movement

• Entry of food material into the anterior sulcus or the presence of residue in the anterior sulcus due to reduced labial tension or tone

• Entry of food material into the lateral sulcus or the presence of residue in the lateral sulcus due to reduced buccal tension or tone

• Abnormal hold position or dropping of material to the floor of the mouth due to tongue thrust or reduced tongue control

• Delayed oral onset of swallow due to apraxia of swallow or reduced oral sensation

• Searching motion or inability to organize tongue movements due to apraxia of swallow

• Forward tongue movement to start the swallow due to tongue thrust

• Residue of food on the tongue due to reduced tongue range of movement or strength

• Disturbed lingual contraction (peristalsis) due to lingual discoordination

• Incomplete tongue-to-palate contact due to reduced tongue elevation

• Inability to mash material due to reduced tongue elevation

• Adherence of food to hard palate due to reduced tongue elevation or reduced lingual strength

• Reduced anterior-posterior lingual action due to reduced lingual coordination

• Repetitive lingual rolling in Parkinson disease[12]

• Uncontrolled bolus or premature loss of liquid or pudding consistency into the pharynx due to reduced tongue control or linguavelar seal

• Piecemeal deglutition

• Delayed oral transit time

Pharyngeal-phase disorders

If pharyngeal clearance is severely impaired, a patient may be unable to ingest sufficient amounts of food and drink to sustain life. In people without dysphagia, small amounts of food commonly are retained in the valleculae or pyriform sinus after swallowing. If there is weakness in or a lack of coordination of the pharyngeal muscles or if there is a poor opening of the upper esophageal sphincter, patients may retain excessive amounts of food in the pharynx and experience overflow aspiration after swallowing.

Dysfunction or abnormalities of the soft palate and superior pharynx (eg, cleft palate) can lead to nasopharyngeal reflux following uvulectomy.

Logemann's Manual for the Videofluorographic Study of Swallowing cites the following pharyngeal-phase swallowing symptoms and disorders[11] :

• Delayed pharyngeal swallow

• Nasal penetration during swallow due to reduced velopharyngeal closure

• Pseudoepiglottis (after total laryngectomy): Fold of mucosa at the base of the tongue

• Cervical osteophytes

• Coating of pharyngeal walls after the swallow due to bilateral reduction of pharyngeal contraction

• Vallecular residue due to reduced posterior movement of the tongue base

• Coating in a depression on the pharyngeal wall due to scar tissue or pharyngeal pouch

• Residue at top of airway due to reduced laryngeal elevation

• Laryngeal penetration and aspiration due to reduced closure of the airway entrance (arytenoid to base of epiglottis)

• Aspiration during swallow due to reduced laryngeal closure

• Stasis of residue in pyriform sinuses due to reduced anterior laryngeal pressure

• Delayed pharyngeal transit time

Esophageal-phase disorders

Impaired esophageal function can result in retention of food and liquid in the esophagus after swallowing. This retention may result from a mechanical obstruction, a motility disorder, or an impairment of the opening of the lower esophageal sphincter.

Achalasia can lead to reduced gastroesophageal junction relaxation or absent esophageal peristalsis.

Logemann's Manual for the Videofluorographic Study of Swallowing cites the following swallowing symptoms and disorders of the esophageal phase[11] :

• Esophageal-to-pharyngeal backflow due to esophageal abnormality

• Tracheoesophageal fistula

• Zenker diverticulum

• Reflux

Zenker diverticulum can lead to swallowing difficulty, with possible nocturnal aspiration of residue in the diverticulum.

Other defects in the wall of the esophagus or in the external structures (eg, in the hilar lymph nodes) can lead to dysfunction in the propulsion of the bolus from the esophagus to the stomach (eg, esophageal webs, rings, strictures; intraluminal obstruction from solids) and result in weak esophagopharyngeal peristalsis due to scleroderma or other conditions.

A study by Kawaguchi et al determined that primary esophageal motility disorder was present in 58 out of 100 study patients with dysphagia, indicating that it has a not uncommon association with swallowing difficulties.[13]

Aspiration

As previously mentioned, aspiration is the passage of food or liquid through the vocal folds. People without swallowing abnormalities routinely aspirate microscopic amounts of food and liquid. Gross aspiration, however, is abnormal and may lead to respiratory complications, including pneumonia. (See the images below.)[14]

Lateral projection of the videoprint of a videographic swallowing study shows residues on the vallecula (Vr) and pyriform sinuses (Pr) and a small amount of aspirated liquid barium in the trachea (As).

Lateral projection of the videoprint of a videographic swallowing study shows subglottic aspiration.

Delayed posteroanterior chest image shows aspiration of liquid barium into the distal bronchus.

Several factors influence the effects of aspiration: quantity, depth, physical properties of the aspirate, and pulmonary clearance mechanisms.

Aspirating material into the distal airways is more dangerous than aspiration into the vocal folds. Solid food may cause fatal airway obstruction, and acidic material is dangerous because the lungs are highly sensitive to the caustic effects of acid. Aspirating material laden with infectious organisms or even normal mouth flora can cause bacterial pneumonitis.

Pulmonary clearance mechanisms include ciliary action and coughing, with aspiration normally provoking a strong reflex cough. If sensation is impaired, silent aspiration may occur.

The severity of aspiration can be described by estimating the percentage of the total bolus aspirated or by estimating the depth of bolus invasion into the airway. The Eight-Point Penetration-Aspiration Scale is an example of an estimation tool.[15]

Central nervous system disorders

Central nervous system (CNS) pathologies that can produce dysphagia include the following:

• Alzheimer disease

• Brain tumors

• Guillain-Barré syndrome

• Huntington disease

• CNS infections

• Stroke

• Traumatic brain injury (TBI)[16]

• Parkinson disease[12, 17]

• Poliomyelitis

• Cerebral palsy

• Multiple sclerosis

• Amyotrophic lateral sclerosis (ALS)[18]

Research by Suntrup-Krueger et al indicated that the location of brain lesions in stroke affects the specific elements of swallowing dysfunction. The investigators found an association between cough reflex disturbance and lesions on the limbic structures of the right hemisphere and sensory regions of the left hemisphere, while oropharyngeal residue and impaired swallow response were found in association with lesions of the parietal-temporal regions of the right hemisphere.[19, 20]

Muscular disorders

Muscular disorders that can cause dysphagia include the following:

• Muscular dystrophies

• Spinal muscular atrophy

• Polymyositis

• Dermatomyositis

Neuropathic disorders

Dysphagia can result from sensory neuropathies affecting the laryngeal nerves.[21, 22]

Endocrine disorders

Dysphagia can result from the following:

• Secondary myopathies in Cushing syndrome, hyperthyroidism, and hypothyroidism

• Vitamin B-12 deficiency: Leading to pseudobulbar palsy secondary to corticobulbar tract dysfunction

Pharmacologic causes

Various medications, including the following, can produce dysphagia by causing a decrease in cognition or giving rise to drug-induced myopathies:

• CNS depressants

• Antipsychotics

• Corticosteroids

• Lipid-lowering agents

• Colchicine

• Aminoglycosides

• Anticholinergic drugs

Mucosal injury may be caused by the following drugs:

• Potassium chloride tablets

• Nonsteroidal anti-inflammatory drugs (NSAIDs)

• Antibiotics (eg, doxycycline, tetracycline, clindamycin, trimethoprim-sulfamethoxazole)

Xerostomia may be caused by the following agents:

• Anticholinergics

• Alpha-adrenergic blockers

• Angiotensin-converting enzyme (ACE) inhibitors

• Antihistamines

Surgical causes

Surgeries that can lead to dysphagia include the following:

• Laryngectomy

• Pharyngectomy, esophagectomy reconstructed by gastric pull-up

• Head and neck surgery (oral cavity cancer)[23]

• Surgery involving the pharyngeal plexus during cervical fusion or carotid endarterectomy

Tracheostomy

The frequency of aspiration in patients with a tracheostomy is 50-83%. The tracheostomy tube affects airway protection and swallowing in many ways. It impairs the glottic closure reflex, reduces subglottic pressure and laryngeal elevation, impairs hypopharyngeal and laryngeal sensation, and leads to disuse muscle atrophy.

Tracheostomy alters the essence of normal respiratory flow by diverting air through the neck instead of the pharynx, especially when an inflated tracheostomy tube cuff is present. The previous belief that an inflated tracheostomy tube cuff prevents aspiration of food has been refuted. An inflated cuff causes secretions to stagnate and collect above it, and these secretions can trickle down past the cuff and potentially lead to infection. Increasing the pressure of the cuff may lead to malacia, stenosis, fistula of the tracheal wall, or dragging of the cuff on the larynx as the larynx elevates during a swallow (laryngeal excursion).

Subglottic airway pressure is disrupted in patients with open tracheostomy tubes. The expiratory phase is shortened because the function of the normal vocal folds to maintain lung volumes throughout the physiologic prolongation of the expiratory phase is impaired. Furthermore, reduced subglottic pressure precludes effective coughing.

Superior and anterior laryngeal excursion during swallowing facilitates vertical closure of the laryngeal vestibule, assisting in airway protection and opening of the upper esophageal sphincter. The tracheostomy tube may attach the larynx to the surrounding neck tissue, anchoring it in position and reducing laryngeal elevation.

The tracheostomy desensitizes laryngeal and hypopharyngeal receptors, delaying onset of the laryngeal adductor reflex response and leading to aspiration. The sensory response, and hence the organization of the swallowing mechanism, can be improved by restoring the transglottic airflow by downsizing the tracheostomy tube, placing a fenestrated tube, or occluding the tracheostomy tube with a cap or with a 1-way speaking valve.

Endotracheal intubation

Endotracheal intubation also affects swallowing function, directly and indirectly. The direct effect of the endotracheal tube on laryngeal structures is caused by laryngeal trauma, which manifests as vocal-fold and supraglottic edema, granulation tissue in the posterior larynx, subluxation of one or both arytenoid cartilages, and permanent or temporary palsy of the recurrent laryngeal nerve. Supraglottic and glottic edema reduces the patient's ability to sense the presence of secretions in the larynx or hypopharynx, which in turn can inhibit the timely triggering of the pharyngeal swallow response, causing aspiration.

Indirect effects on swallowing caused by endotracheal intubation relate to the coordination required between respiration and the swallowing function. An increased respiratory rate in patients with suboptimal oxygenation can disrupt the regular swallowing and respiration pattern and predispose the patient to aspiration of saliva and secretions.

For example, continuous, positive airway pressure delays the latency of the swallow response and reduces the number of swallows, because it alters the peripheral sensory receptors that assist with the triggering of a pharyngeal swallow.

Additional iatrogenic causes of dysphagia

These include the following:

• Use of a cervical brace

• Ventilator dependency

Psychogenic dysphagia

This diagnosis is one of exclusion. The condition is characterized by oral apraxia with intact speech and pharyngoesophageal and neurologic function.

Associated psychiatric conditions include anxiety, depression, somatoform disorders, hypochondriasis, conversion disorders, and eating disorders. Psychiatric evaluation and treatment often are needed.

Instances of swallowed foreign bodies do occur (bezoars), especially in patients with developmental disabilities, and this possibility also should be considered.

Motility disorders

Motility disorders that can produce dysphagia include the following:

• Diffuse esophageal spasms (DES)

• Achalasia (megaesophagus)

• Scleroderma

• Presbyesophagus

• Cricopharyngeal dysfunction

Esophagitis

The following may also result in dysphagia[24] :

• Gastroesophageal reflux disease (GERD)

• Infectious esophagitis (eg, as in human immunodeficiency virus [HIV], herpes, candidiasis)

• Radiation esophagitis: Especially after radiation treatments of 4500 to 6000 rad over 6-8 weeks

• Medication-induced esophagitis: May develop from enteric-coated nonsteroidal anti-inflammatory drugs (NSAIDs); substances such as quinidine, potassium, vitamins, and FeSO4 also may produce esophageal injury

Structural disorders

These include the following:

• Zenker diverticulum at the upper esophagus or epiphrenic diverticula at the midesophagus or distal esophagus

• Esophageal strictures, webs, or rings

• Tracheoesophageal fistula

• Schatzki rings

• Plummer-Vinson or Paterson-Kelly syndromes and hypopharyngeal webs with iron deficiency anemia

• Cervical spondylosis

Occurrence in the United States

Neurologic swallowing disorders are encountered more frequently in rehabilitation medicine than in most other medical specialties. Stroke is the leading cause of neurologic dysphagia, with the condition occurring in approximately 51-73% of patients with stroke. Dysphagia can delay functional recovery in patients with stroke and is also the most significant risk factor for the development of pneumonia in this population.

Race- and age-related demographics

According to the US National Medicare database, the incidence of poststroke dysphagia is higher in Asians and other minority groups than in whites, suggesting racial disparities in the development of dysphagia after stroke.[25, 26]

As previously mentioned, the prevalence of dysphagia increases with age, and dysphagia is a major health-care problem in elderly patients.

A study by Kooi-van Es et al found that of 295 children with neuromuscular disease, dysphagia and dysarthria had a pooled overall prevalence of 47.2% and 31.5%, respectively. The investigators reported that 90.0% of children with dysphagia had chewing problems, while 43.0% had swallowing problems, and 33.3% demonstrated difficulties with both chewing and swallowing.[27]

Stroke patients recover swallowing function gradually, and therapeutic interventions for dysphagia generally are successful. In a prospective investigation of 128 patients admitted because of acute stroke, a swallowing abnormality was detected in 51% on clinical examination and in 64% on videofluoroscopy at initial presentation.[28] At 6 months after stroke, 87% of patients had returned to their prestroke diet.

In conditions in which recovery is possible (eg, TBI, stroke), the normalization of swallowing may take from 3 weeks to approximately 6 months or longer.[29, 1] Many patients tolerate normal oral caloric intake 9 months after a stroke, while some may require partial or nonoral caloric supplementation. In patients who have sustained a stroke, continued swallowing dysfunction after 6 months is associated with increased morbidity and mortality.

In static or progressive conditions (eg, neuromuscular disorders, postpolio syndrome), periodic evaluation of swallowing disorders is mandatory, especially with the onset of new symptoms, and the appropriate strategies (the use of nonoral feeding techniques or new compensatory mechanisms) should be considered.

Aspiration pneumonia

Pneumonia accounts for about 34% of all stroke-related deaths and represents the third highest cause of death during the first month after a stroke. Although not all of these cases of pneumonia are attributable to the aspiration of food, the early detection and treatment of dysphagia in patients who have sustained a stroke is nonetheless very critical.[30]

In a study of 124 patients with acute stroke, 39% of them had failing results on initial swallow screening.[31] However, because of early management (eg, altered dietary texture) of their dysphagia, no patients developed aspiration pneumonia. Early swallow screening and dysphagia management in patients with acute stroke reduces their risk of aspiration pneumonia, is cost effective, and helps to ensure good-quality care with optimal outcomes.

Malnutrition

Patients who have had a stroke are likely to decrease their dietary intake, which increases their risk of malnutrition or exacerbates existing malnourishment.[32] In an investigation of the nutritional status of patients with stroke who were admitted to a rehabilitation service, 49% had malnutrition, and 65% of those with dysphagia were malnourished.[33]

In another study, no differences were found in the nutritional parameters of patients admitted for stroke with or without dysphagia on admission. However, after 1 week, 48.3% of the patients with dysphagia were malnourished, compared with only 13.6% of those without dysphagia.

Malnutrition is a risk factor for pneumonia because it renders the person susceptible to altered colonization in the oropharynx and reduced resistance to infection by depressing the immune system. Malnutrition may also lead to lethargy, weakness, and reduced alertness, all of which may increase the probability of aspiration. In addition, malnutrition may reduce the strength of cough and mechanical clearance in the lungs.

A study by Gourin et al indicated that dysphagia-associated malnutrition is a significant risk factor for health outcomes in patients with head and neck cancer. In a study of 93,663 patients treated with ablative therapy for malignant neoplasms of the oral cavity, larynx, hypopharynx, or oropharynx, the investigators found that dysphagia was the most significant of several factors related to weight loss in these patients. The study also indicated that an association exists between weight loss and increases in medical and surgical complications, as well as in length of hospital stay and hospital-related costs, in patients who undergo head and neck cancer surgery.[34]

Dehydration

Dysphagia can potentially lead to dehydration, while dehydration may itself be a risk factor for pneumonia for several reasons. First, it decreases salivary flow, which promotes altered colonization of the oropharynx; second, it may lead to lethargy, mental confusion, and increased aspiration; and third, it makes the person susceptible to infection by depressing the immune system.

Disorders leading to dysphagia may affect the oral, pharyngeal, or esophageal phases of swallowing. Thorough history taking and careful physical examination are important in the diagnosis and treatment of dysphagia. The bedside physical examination should include examination of the neck, mouth, oropharynx, and larynx. A neurologic examination also should be performed.

Specific questions about the onset, duration, and severity of dysphagia and about a variety of associated symptoms may help to narrow the differential diagnosis. Review the patient's general health information, including long-term illnesses and current prescription medications.

Patients who have dysphagia may present with a variety of signs and symptoms. They usually report coughing or choking or the abnormal sensation of food sticking in the back of the throat or upper chest when they are trying to swallow; however, some of these presentations can be quite subtle or even absent (eg, in patients with silent aspiration).[35, 36, 37]

Signs and symptoms of oral or pharyngeal dysphagia include the following:

• Coughing or choking with swallowing

• Difficulty initiating swallowing

• Food sticking in the throat

• Sialorrhea

• Unexplained weight loss

• Change in dietary habits

• Recurrent pneumonia

• Change in voice or speech (wet voice)

• Nasal regurgitation

Signs and symptoms of esophageal dysphagia include the following:

• Sensation of food sticking in the chest or throat

• Change in dietary habits

• Recurrent pneumonia[1]

• Symptoms of gastroesophageal reflux disease (GERD), including heartburn, belching, sour regurgitation, and water brash

Other associated factors/symptoms of dysphagia include the following:

• General weakness

• Mental status changes

Morbidities

Relevant patient history also includes occurrence of the following:

• Recent stroke[29, 1, 3, 10]

• Neuromuscular disease

• Hypertension

• Diabetes mellitus (DM)

• Thyroid disease

• Cancer

• Nephropathic cystinosis

• Dementia

• Recent injection of botulinum toxin[38]

• Traumatic brain injury (TBI)[39]

The bedside physical examination should include examination of the neck, mouth, oropharynx, and larynx. A neurologic examination also should be performed.

Look for oral-motor and laryngeal mechanisms; testing of cranial nerves V and VII-XII is essential for determining whether physical evidence of oropharyngeal dysphagia exists. Direct observation of the following is necessary:

• Lip closure

• Jaw closure

• Chewing and mastication

• Tongue mobility and strength

• Palatal and laryngeal elevation

• Salivation

• Oral sensitivity

Check the patient's level of alertness and cognitive status, because they can impact the safety of swallowing and the ability to learn compensatory measures. Dysphonia and dysarthria are signs of motor dysfunction of the structures involved in oral and pharyngeal swallowing. (The neurologic exam should also include an examination of muscle strength, reflexes, coordination, gait, and functional status.)

Inspect the oral cavity and pharynx for mucosal integrity and dentition, and examine the soft palate for position and symmetry during phonation and at rest.

Evaluate pharyngeal elevation by placing 2 fingers on the larynx and assessing movement during a volitional swallow; this technique helps to identify the presence or absence of key laryngeal protective mechanisms.

The gag reflex is elicited by stroking the pharyngeal mucosa with a tongue depressor. Testing for the gag reflex is helpful, but absence of the reflex does not necessarily indicate that a patient is unable to swallow safely; many people with no gag reflex have normal swallowing abilities, and some patients with dysphagia have a normal gag reflex. Pulling of the palate to one side during testing of the gag reflex indicates weakness of the muscles of the contralateral palate and suggests unilateral bulbar pathology.

Cervical auscultation becomes part of the clinical evaluation of dysphagic patients; assess sound strength and clarity, the timing of apneic episodes, and the speed of swallowing. Also assess respiratory function; if the respiratory force of a cough or clearing of the throat is inadequate, the risk of aspiration is increased. In addition, lungs should be checked for rales/crepitations, wheezes, rhonchi, air entry, and other abnormalities.

The final step in the physical examination is direct observation of the act of swallowing; at a minimum, watch the patient while he/she drinks a few ounces of water. If possible, assess the patient's eating of various food textures. Sialorrhea, delayed swallow initiation, coughing, or a wet or hoarse voice quality may indicate a problem.

After the swallow, observe the patient for 1 minute or more to see if a delayed cough response is present. DePippo and colleagues suggested that a swallow test be conducted with 3 oz of water. In their investigation, the test helped them to identify 80% of patients with stroke who, during a subsequent videofluoroscopic study, were found to be aspirating.[40]

History and physical examination alone may not be adequate to make a diagnosis in cases of silent aspiration. Further diagnostic tests, such as the following, should be performed as needed:

• Transnasal esophagoscopy: Especially useful in cases of esophageal diverticula or tumor[41]

• Cervical auscultation: Permits the clinician to assess pharyngeal swallow by listening to stereotypical sounds through a stethoscope; cervical auscultation may be a useful bedside tool, especially in the absence of other diagnostic tools

• Blood tests: Including thyroid-stimulating hormone, vitamin B-12, and creatine kinase; may be useful, especially in neurogenic dysphagia

• Imaging studies: May include videofluoroscopy, CT scanning, MRI, chest radiography

• Endoscopic examination

• Esophageal pH monitoring: The criterion standard for diagnosing reflux disease; a nasogastric probe is inserted into the patient's esophagus to record pH levels, and these are compared with the patient's record of symptoms over 24 hours to determine whether acid reflux contributes to the patient’s symptoms

• Pulmonary function tests

The above list of tests is not exhaustive, and further tests may be required if there is a need to follow up on other associated findings during the initial evaluation. Consultations with and further evaluations by an ear, nose, and throat (ENT) surgeon and a speech-language therapist also may be necessary.

Chest radiography

Chest radiography is a simple assessment for pneumonia. The image below shows aspiration of liquid barium into the distal bronchus.

Delayed posteroanterior chest image shows aspiration of liquid barium into the distal bronchus.

Ultrasonography

Ultrasonography is used to evaluate soft-tissue dynamics during the oral and pharyngeal phases of swallowing, looking at tongue function and laryngeal/hyoid elevation. Ultrasonography is useful in diagnosing childhood tongue incoordination and could be combined with fiberoptic endoscopic examination of swallowing (FEES) to diagnose extramural and submucosal lesions that FEES alone may not detect.

CT scanning and MRI

CT scanning and MRI provide excellent definition of structural abnormalities, particularly when they are used to evaluate patients with suspected CNS causes of dysphagia.

Videofluoroscopy

Videofluoroscopy is designed to study the anatomy and physiology of the oral, pharyngeal, and esophageal stages of deglutition. It is considered the standard for identifying patients who have the potential to develop pneumonia and for diagnosing aspiration and swallowing problems.[42] It is also used in determining dietary and compensatory strategies. (The terms videofluoroscopic swallowing study [VFSS] and modified barium swallow [MBS] often are used interchangeably.)[43]

Although some clinical researchers believe that it is possible to identify patients with the potential to develop pneumonia by interpreting findings of bedside tests, most agree that discrepancies exist between findings of bedside tests and videofluoroscopy.[44]

Splaingard and colleagues reported that only 42% of patients who had aspiration on videofluoroscopy were diagnosed as aspirators by speech/language pathologists conducting bedside evaluations.[42] This finding indicated that bedside results are not sufficient for evaluating the frequency of aspiration. In general, 40-70% of patients have silent aspiration, which does not manifest specific symptoms.

If a patient undergoing a VFSS aspirates or if he/she retains food after swallowing, the next step is to evaluate the quantity of retained food, the mechanism of retention or aspiration, and the patient's response. In general, various food consistencies, volumes, postural techniques, and swallowing maneuvers to enhance swallowing efficiency or safety are tested during the study, and clinical decisions (eg, changing food viscosity, finding appropriate swallowing postures or maneuvers) are made.

This study is expensive because of the special expertise, equipment, and facilities required. (See the images below of videofluoroscopic swallowing findings.)

Lateral projection of the videoprint of a videographic swallowing study shows the epiglottis (E), pyriform sinuses (P), tongue (Tg), trachea (Tr), and vallecula (V).

Lateral projection of the videoprint of a videographic swallowing study shows residues on the vallecula (Vr) and pyriform sinuses (Pr) and a small amount of aspirated liquid barium in the trachea (As).

Anterior projection of the videoprint of a videographic swallowing study shows residues on the vallecula (Vr) and pyriform sinuses (Pr).

Lateral projection of the videoprint of a videographic swallowing study shows supraglottic penetration.

Lateral projection of the videoprint of a videographic swallowing study shows subglottic aspiration.

Scintigraphy

Scintigraphy has limited value in evaluating pharyngeal swallowing disorders. This test is useful in quantitative and qualitative evaluation of subglottic aspiration, esophageal motility disorders, and gastroesophageal reflux.[45]

Oropharyngeal transit time can be measured through time-activity curves constructed from a specific region of interest (ROI) of the mouth, pharynx, and esophagus. Peaks and nadirs of the first derivative curve correspond to peak emptying or filling rates of the respective regions.

Scintigraphic examination of dysphagia entails having the patient swallow a technetium-99m (99m Tc) sulfur colloid bolus in order to label oral secretions. Neck and chest imaging is subsequently performed to detect aspirations.

FEES

An FEES is used to evaluate any structural abnormalities in the nasopharynx, laryngopharynx, and hypopharynx and is particularly useful when a VFSS is not feasible (eg, in critically ill patients unable to tolerate any risk of aspiration, patients in intensive care units who cannot be transferred to the fluoroscopy room, or patients who require prompt evaluation).[43]

The FEES uses a transnasal laryngoscope, and swallowing is directly evaluated by using measured quantities of food colored with blue liquid dye. It is a sensitive technique for detecting premature bolus loss, laryngeal penetration, tracheal aspiration, and pharyngeal residue. Because pharyngeal contraction obstructs the lumen, the FEES does not demonstrate the motion of essential food pathway structures or show the food bolus during the swallow.

Gastroesophageal endoscopy

Gastroesophageal endoscopy enables the best assessment of the esophageal mucosa. Endoscopy has the added benefits of permitting the detection of infection and erosions and of enabling biopsy.

For the reflex cough test, a 20% solution of L-tartaric acid is dissolved in 2 mL of sterile normal saline. Using a nasal nebulizer, the patient inhales the solution, which stimulates cough receptors in the vestibule of the larynx and initiates the laryngeal cough reflex.

The laryngeal cough reflex protects the laryngeal aditus from significant aspiration and reduces the risk of respiratory complications (eg, pneumonia). An impaired laryngeal cough reflex may permit laryngeal penetration and increase the risk of aspiration pneumonia. An acute cerebrovascular accident often appears to affect the protective cough reflex.

Using a reflex cough test, Addington and colleagues were able to identify which patients with stroke were unlikely to subsequently develop aspiration pneumonia (specificity, 100%).[46]

Electromyography (EMG) is of limited use clinically. It is employed mainly in research to evaluate individual myoelectric function.

Swallowing electromyography

Mechanical upward-downward movement of the larynx is detected by using a piezoelectric sensor while submental integrated EMG activity is recorded during dry and wet swallowing. EMG activity of the cricopharyngeal muscle of the upper esophageal sphincter also can be recorded.[47]

In patients with muscular disorders, laryngeal elevators are involved, whereas the cricopharyngeal sphincter is intact. In patients with clinical signs of involvement of the corticobulbar fiber (eg, patients with ALS and pseudobulbar palsy), discoordination between paretic laryngeal elevators and the hyperreflexic cricopharyngeal sphincter is present.

EMG can be used for muscle selection and for performing injections of botulinum toxin in patients with dysphagia caused by cricopharyngeal muscle spasm or hypertonicity.

Laryngeal electromyography

Laryngeal EMG can help the clinician to diagnose oropharyngeal dysphagia of peripheral nerve origin (eg, from recurrent laryngeal or superior laryngeal nerve injury).

Manometry

Manometry is performed to assess motor function of the esophagus. A catheter with several electronic pressure probes is passed into the stomach to measure esophageal contractions and to define upper and lower esophageal responses to swallowing. Manometry reveals definitive abnormalities in only 25% of patients with nonobstructive lesions; therefore, its clinical use in oropharyngeal dysphagia is limited.

Manometric fluoroscopy consists of manometry combined with VFSS. It is used to check the pressure gradient of the pharynx and the pharyngoesophageal junction.

The goals of dysphagia treatment are to maintain adequate nutritional intake for the patient and to maximize airway protection.

Disorders of oral and pharyngeal swallowing are usually amenable to rehabilitation, including dietary modification and training in swallowing techniques and maneuvers.[1] Surgery is rarely indicated for patients with swallowing disorders, although in patients with severe disorders, bypassing the oral cavity and pharynx in their entirety and providing enteral nutrition may be necessary. Options include percutaneous endoscopic gastrostomy and intermittent oroesophageal catheterization.

Various treatments have been suggested for the treatment of oropharyngeal dysphagia in adults. Direct and indirect strategies for treating dysphagia have been described. Direct strategy usually refers to treatment that involves food, whereas indirect strategy refers to an exercise regimen performed without a food bolus. Direct techniques include modifications of food consistency; indirect techniques include stimulation of the oropharyngeal structures and the adoption of behavioral techniques, such as those involving postural changes or the swallow maneuver.[48, 49]

The Dietetics in Physical Medicine and Rehabilitation dietetic practice group conceived the National Dysphagia Diet project in 1996. This group became known as the National Dysphagia Diet Task Force (NDDTF). Growing frustration regarding a lack of standardization for solid-food textures, liquid consistencies, and nomenclature led to the formation of a task force to study the issue and to formulate a new diet based on scientific food properties and clinical swallowing problems. In 2002, the American Dietetic Association established the National Dysphagia Diet (NDD) to provide national guidelines and standardized terminology for texture modification for dysphagia management. The NDD contains suggested viscosity ranges for different types of modified fluids.[50]

Medications used in the treatment of dysphagia include the following:

• Botulinum toxin type A (BoNT-A): Injected endoscopically into the gastroesophageal sphincter and upper esophagus to decrease tone; this can be very useful in cricopharyngeal spasms causing dysphagia[51]

• Diltiazem: Can aid in esophageal contractions and motility, especially in the disorder known as the nutcracker esophagus

• Cystine-depleting therapy with cysteamine: Treatment of choice for patients with dysphagia due to pretransplantation or posttransplantation cystinosis[52]

• Nitrates: Including isosorbide dinitrate, which can especially be recommended in achalasia

Dietary modification is the key component in the general treatment program of dysphagia. A diet of pureed foods is recommended for patients who have difficulties with the oral preparatory phase of swallowing, who pocket food in the buccal recesses, or who have significant pharyngeal retention of chewed solid foods.

As patients' swallowing function improves, their dysphagic diet may be advanced to the next level of soft and semisolid foods with regular consistencies. Recommend to patients that they alternate bites with sips, bite or sip size, and the number of swallows per size.

Viscosity and texture

Food viscosity is defined as frictional resistance to shear. Food texture is defined as the group of physical properties derived from the structure of the food that can be sensed by touch. Touch usually is performed by elements of the oral and pharyngeal cavities. Food and liquid textures play important roles in the care of patients with dysphagia.

If oral feedings are determined to be appropriate, the viscosity and texture of the food should be considered, because patients vary in their ability to swallow thin and thick liquids. Liquids can be thickened with various thickening agents. Many commercially available, starch-based food thickeners are used to increase the consistency of food, and prethickened water, juice, coffee, and other products are available.

A uniform and viscous bolus of food or beverage enables a patient with a delayed swallow reflex to control mastication and transport. It also allows the individual to swallow with less risk of aspirating residue material, because there is a reduced tendency for the material to fall over the base of the tongue before the swallow mechanism is triggered. Viscosity also influences the swallowing reflex and peristaltic activity.

Viscosity of the diet for dysphagia is frequently described in a nonobjective manner. For example, tomato juice, nectar, honey, and pudding have been referred to as fluids.

Viscosity can be objectively determined by using a device called a viscometer. Another objective method of determining viscosity is a line-spread test.[53, 54] In this, diluted mix is placed on a circle marked on a glass plate and is allowed to stream for 5 minutes. Lengths of the 4 stream directions are measured, and their mean is determined.

Diet classifications

The dysphagia diet can be classified according to viscosity, as follows:

• level I: Pudding, crushed potato, and ground meat

• level II: Curd-type yogurt, orange juice (mixed with 3% thickener), cream soup, and thin soup with starch

• level III: Tomato juice, fluid-type yogurt, and thick, fluid rice

• level IV: Water and orange juice

Diets for patients with dysphagia include the following:

• Dysphagia diet 1: Thin liquids (eg, fruit juice, coffee, tea)

• Dysphagia diet 2: Nectar-thick liquids (eg, cream soup, tomato juice)

• Dysphagia diet 3: Honey-thick liquids (ie, liquids that are thickened to a honey consistency)

• Dysphagia diet 4: Pudding-thick liquids/foods (eg, mashed bananas, cooked cereals, purees)

• Dysphagia diet 5: Mechanical soft foods (eg, meat loaf, baked beans, casseroles)

• Dysphagia diet 6: Chewy foods (eg, pizza, cheese, bagels)

• Dysphagia diet 7: Foods that fall apart (eg, bread, rice, muffins)

• Dysphagia diet 8: Mixed textures

Nutritional evaluation and support

The effect of dysphagia on the patient's nutritional status is profound. As the patient's ability to swallow becomes impaired, adequate dietary intake becomes a challenge, and vice versa. Therefore, early detection and management of dysphagia are critical to halting malnutrition.[55]

Malnutrition is a risk factor for pneumonia because it renders patients susceptible to altered microbial colonization in the oropharynx and because it depresses the immune system, reducing resistance to infection. It may also lead to lethargy, weakness, and reduced alertness, all of which may increase the probability of aspiration.

Moreover, malnutrition may reduce the strength of cough and the mechanical clearance of the lungs. It also contributes to overall functional decline, muscle breakdown, osteoporosis, osteopenia, iron-deficiency anemia, skin breakdown, and poor wound healing.

Therefore, in addition to dysphagia screening, formal nutritional assessment is necessary in high-risk patients. Nutritional needs are determined by means of thorough body composition analysis, clinical examination, and biochemical assessment. Energy, protein, and fluid requirements must also be assessed.

In an investigation of the nutritional status of patients admitted to a rehabilitation service, 49% of all patients admitted for stroke were malnourished,[33] and 65% of persons admitted for stroke with dysphagia were malnourished.[28]

Many commercial products are available to provide nutritional support. A patient's protein and calorie intake can be enhanced not only with thickening agents but also with prethickened beverages, prepacked puree molds, oral liquid supplements, and modular components. When oral nutrition is inadequate, enteral nutrition is indicated.

Because fluid intake is restricted in most patients with dysphagia, these individuals are at risk of dehydration. Therefore, the patient's hydration status must be closely monitored. Dehydration may lead to lethargy, mental confusion, and increased aspiration. In addition, dehydration depresses the immune system, making the patient susceptible to infection, and it may also be a risk factor for pneumonia, because it decreases salivary flow (thus promoting altered microbial colonization of the oropharynx).

The hydration state of a patient can be assessed by using input and output records, laboratory values (eg, serum osmolality), and physical indicators (eg, dry mucous membranes, poor skin turgor, darkened urine).

Adequate fluid intake can be achieved through simple interventions, such as systematically offering patients preferred liquids or foods with high fluid content (eg, pureed fruits and vegetables, hot cereals, custards, puddings) and having an adequate number of supervised staff to help patients drink while properly positioned. Intravenous fluids or water boluses given via a feeding tube may be necessary if hydration cannot be maintained.

Oral hygiene and dental care are important. Changes in the oral milieu may occur secondary to decreased salivary production and abnormalities in swallowing. These abnormalities may result in the impaired clearance of organisms, allowing for pathogenic colonization. Dried secretions that accumulate on the tongue and palate reduce oral sensitivity and promote bacterial growth. Lemon glycerin swabs or a damp washcloth can be used to remove the secretions.

The elderly have an increased incidence of oropharyngeal colonization with respiratory pathogens, a well-known risk factor for pneumonia, making oral care extremely important in pneumonia prevention.

Exercises are used to increase muscle tone and augment pharyngeal swallow. Two types of exercise can be recommended to patients with dysphagia: indirect (eg, exercises to strengthen swallowing muscles) and direct (eg, exercises to be performed while swallowing).

Exercise techniques are geared especially toward range of motion (ROM), coordination, and the strengthening of muscles of the jaw, lips, cheek, tongue, soft palate, and vocal cords. Exercises designed to facilitate oral motor strength, ROM, and coordination usually are performed 5-10 times per day.

Biofeedback techniques are used to reeducate muscles affected in facial palsy and disorders of articulation. Such techniques include electromyographic feedback, with surface electrodes placed over the anterior neck. Visual feedback is obtained through a videofluoroscopic swallowing study (VFSS) while experimentation with head positions and swallowing maneuvers is conducted.

Lips

Lip exercises can facilitate the patient's ability to prevent food or liquid from leaking out of the oral cavity. Tongue exercises are used to facilitate manipulation of the bolus and its propulsion through the oral cavity or to facilitate retraction of the tongue base. Passive ROM and active-assistive ROM exercise concepts also can be applied in this technique. Tongue-holding maneuvers facilitate compensatory anterior movement of the posterior pharyngeal wall.

Head lift

Head-lift exercises increase anterior movement of the hyolaryngeal complex and opening of the upper esophageal sphincter. Patients lie flat and are instructed to keep their shoulders on the floor as they raise their head high enough to see their toes, maintaining this position for 1 minute. They repeat this activity 3 times, followed by 30 consecutive repetitions of the same action. Patients should perform this exercise 3 times per day for several weeks.

A study by Choi et al indicated that combining head-lift exercises with conventional dysphagia therapy is more effective than conventional dysphagia therapy alone in the treatment of poststroke dysphagia. Greater improvement in degree of aspiration (evaluated using the Penetration-Aspiration Scale) and oral diet level (assessed via the Functional Oral Intake Scale) was seen in the head-lift group than in the patients who received only conventional treatment.[56]

Other

Jaw exercises help to facilitate the rotatory movements of mastication. Respiratory exercises (eg, resistive straw sucking, coughing, incentive spirometer) are recommended to improve respiratory strength. Vocal cord adduction exercises can promote strengthening of weak vocal cords.

Electrical stimulation can be applied for dysphagia, being administered with a modified, handheld, battery-powered electric stimulator connected to a pair of electrodes positioned on the neck. This technique is comparable to neuromuscular stimulation or functional electrical stimulation applied to the limb.

Somatosensory input influences motor function, and oral sensory deficit is associated with increased tendency toward aspiration. Somatosensory stimulation in the form of an electrical current applied to the pharynx can change the excitability of the corticobulbar projection and induce cortical reorganization in patients with poststroke dysphagia.[57, 58, 59]

Deep pharyngeal neuromuscular stimulation (DPNS) is a therapeutic program that uses the afferent-efferent cycle (ie, sensory stimulation-motor response) to improve pharyngeal swallow. DPNS focuses on stimulating 3 reflex sites with frozen lemon-glycerin swabs. The first site—the bitter taste buds and tongue base—is used to improve tongue-base retraction. The second site is the soft palate, which is stimulated to improve palatal elevation. The therapy is applied to the third site, the superior and medial pharyngeal constrictor, to improve pharyngeal peristalsis and cricopharyngeal opening.

A pilot randomized, controlled study by Sproson et al reported that better poststroke swallowing rehabilitation results were obtained with the use of a combination of transcutaneous neuromuscular electrical stimulation and swallow-strengthening exercises than with usual dysphagia care. The study noted improvement in 75% of patients in the electrical stimulation group, compared with 57% of those receiving usual care.[60]

Tactile-thermal stimulation (TTS) can be used to increase the speed of swallow. TTS involves the application of cold by rubbing the bilateral anterior facial arch with a laryngeal mirror that has been placed in ice. The purpose is to sensitize the area of the oral cavity where the swallow is triggered.

The bite reflex can be inhibited by applying sustained pressure to the tongue with a rubber seizure stick, in the chin-tuck position. A hypoactive gag reflex can be facilitated by applying a tongue depressor or a quick tap to the arch of the soft palate. A hyperactive gag can be desensitized by using firm pressure with a tongue depressor, which is advanced farther back in the mouth.

Maintaining oral feeding often requires compensatory techniques to reduce aspiration or improve pharyngeal clearance.

Chin-tuck position

In this, the patient holds his/her chin down, increasing the epiglottic angles, and pushes the anterior laryngeal wall backward, thereby decreasing the airway diameter.

The chin-tuck position decreases the space between the base of the tongue and the posterior pharyngeal wall, creating increased pharyngeal pressure to move the bolus through the pharyngeal region. Use of this position often is helpful for patients with delayed swallow reflex, because, by narrowing the airway entrance and increasing the vallecular space, it increases the probability that the bolus will remain in the vallecular before the pharyngeal swallow is triggered. In this way, the risk of aspiration is decreased.

Rotation of the head to the affected side

This technique closes the pyriform sinus on the affected side, directing food down the opposite, stronger side. This posture also adds external pressure on the damaged vocal cord and moves it toward the midline, improving airway closure.

Tilting of the head to the strong side

By tilting the head to the strong side, the bolus tends to be directed down the stronger side in the oral cavity and in the pharynx. The head tilt is also effective for patients who have unilateral tongue dysfunction or a unilateral pharyngeal disorder.

Lying on one's side or back during swallowing

Using this posture often helps patients who, because of residue in the pharynx, aspirate after swallowing. Such aspiration occurs because gravity drops the residual food into the airway when they inhale after the swallow.

Supraglottic swallow

The supraglottic swallow, a technique that most patients can master, involves simultaneous swallowing and breath-holding, closing the vocal cords and protecting the trachea from aspiration. The patient thereafter can cough to expel any residue in the laryngeal vestibule. This technique can be useful for patients who have reduced laryngeal closure. Advise the patient to practice the following steps[61] :

• Take a deep breath and hold your breath

• Keep holding your breath and lightly cover your tracheostomy tube, if applicable

• Keep holding your breath while you swallow

• Cough immediately after the swallow

The extended supraglottic swallow is helpful for patients with severe reductions in tongue mobility or severely reduced tongue bulk due to surgical procedures for oral cancer, because these persons essentially have little or no oral transit. Advise these patients to learn the following technique:

• Hold your breath firmly

• Put the entire 5-10 mL of liquid in your mouth

• Continue to hold your breath and toss your head back, thus dumping the liquid into the pharynx as a whole

• Swallow 2-3 times or as many times as needed to clear the majority of the liquid while continuing to hold your breath

• Cough to clear any residue from the pharynx

The supersupraglottic swallow incorporates the supraglottic swallow with a Valsalva effect. This technique is designed to close the airway entrance voluntarily by tilting the arytenoid cartilage anteriorly to the base of the epiglottis before and during the swallow. This strategy is used in patients with reduced closure of the airway entrance, particularly those who have undergone supraglottic laryngectomy.

Bolus-clearing maneuvers

The effortful swallow is designed to improve posterior tongue-base movement, in that way improving clearance of the bolus from the valleculae. Patients are instructed to swallow hard.

Mendelsohn maneuver

This maneuver is a form of supraglottic swallow in which the patient mimics the upward movement of the larynx by voluntarily holding the larynx at its maximum height to increase the duration of the cricopharyngeal opening. Patients are instructed to swallow, to hold the swallow for 2-3 seconds, and then to complete the swallow and relax when the pharynx is in the uppermost stage. Repeatedly swallowing and washing food through the pharynx may be helpful to patients who have excessive residue in the pharynx after the swallow.

In some patients, enteral feeding may be necessary in order to bypass the oral cavity and pharynx. In general, enteral feeding is indicated in any patient who is unable to achieve adequate alimentation and hydration by mouth. Patients with an impaired level of consciousness, massive aspiration, silent aspiration, esophageal obstruction, or recurrent respiratory infections fall into this category.

There has been some controversy regarding the most appropriate mode and method of administering enteral feeding (eg, continuous or intermittent, intestinal or gastric). Esophagostomy is needed in patients in whom other placements may not be possible and can help in the control of pharyngeal secretions.

Nasogastric tube feeding

Nasogastric tube (NGT) feeding is a commonly used method of enteral feeding. In patients with a short-term life expectancy, nasogastric feeding is a more appropriate route for enteral nutrition. Insertion of an NGT is an easy, quick, relatively noninvasive procedure; it requires little training and is associated with negligible mortality. However, many patients find the NGT uncomfortable and repeatedly pull the tube out, which results in interrupted feeding and potential malnutrition.

Its prolonged use can lead to complications, such as lesions to the nasal wing, chronic sinusitis, gastroesophageal reflux, and aspiration pneumonia, although H2 blockers or proton-pump inhibitors given as prophylaxis can prevent some complications.[62]

Oroesophageal tube feeding

Campbell-Taylor and colleagues introduced oroesophageal tube feeding in 1988 (see the image below).[63] Patients who refuse nasogastric or gastrostomy tubes can use this method. The patient is taught to insert the 14F urethral tube into the mouth and past the side of the tongue, pushing slowly until the catheter end reaches the lips. Food supplements and liquid are administered by means of a 500-mL syringe at a rate of approximately 50 mL/min.

Oroesophageal tube feeding can be used by patients who decline to be enterally fed through a nasogastric or gastrostomy tube.

The absence of a gag reflex indicates the possible need for oroesophageal tube feeding. The patient must be cooperative and alert but need not be completely cognitively intact. This method is relatively contraindicated in patients with a hyperexaggerated gag reflex, esophagitis, Zenker diverticulum, or anteriorly directed cervical osteophytes.

This method has several advantages. First, oroesophageal tube feeding may prevent the harmful effects of continuous NGT feeding. Second, the speed of pouring liquids can be faster than with NGT feedings. Third, oroesophageal tube feeding provides training for facilitating the swallowing reflex.

However, a couple of disadvantages should also be noted. First, performance of this procedure requires skillful technique. Second, the need for frequent manipulation (6 times per day) may be troublesome for the assistant.

Percutaneous endoscopic gastrostomy

Percutaneous endoscopic gastrostomy (PEG), in which endoscopy is used to percutaneously place a tube into the stomach, has several advantages over surgical gastrostomy (which requires a laparotomy under general or local anesthesia). These include reduced procedure time, cost, and recovery time, as well as the fact that PEG requires no general anesthesia. However, PEG does require the invasive insertion of the feeding tube through the anterior abdominal wall, which can result in complications, including the following[64] :

• Bleeding

• Peritonitis or perforation of other abdominal organs

• Chest infections

• Local infection around the insertion site

• The tubes being pulled out

Relative contraindications for PEG are aspiration pneumonia due to gastroesophageal reflux, significant ascites, and morbid obesity. Prospective, randomized trials have shown increased compliance, convenience, and continuity of feeding with PEG tubes compared with nasogastric intubation.

Reflux prevention involves feeding the patient in a vertical position, using H2 blockers to decrease gastric pH, chlorpromazine or Maxolon to facilitate gastric emptying, and proton-pump inhibitors to decrease gastroesophageal reflux.

In one meta-analysis comparing effectiveness and safety between NGT feeding and PEG, PEG was found to be safer and more effective than NGT use. Intervention failure occurred in 19 of 156 patients in the PEG group, compared with 63 of 158 patients in the NGT group. However, complications, mortality rates, and pneumonia rates were comparable between NGT feeding and PEG.[65]

Cricopharyngeal myotomy (CPM) is a procedure designed to decrease pressure on the pharyngoesophageal sphincter (PES) by incising the main muscular component of the PES. However, no means of precisely determining the underlying PES dysfunction exists. For this reason, no rational guidelines have been compiled for recommending CPM.

Even less certain is the advisability of performing a CPM in patients with neurogenic dysphagia, such as patients with stroke. The fact that neurogenic causes of dysphagia usually involve a lack of coordination of the swallow rather than any intrinsic or extrinsic muscle dysfunction probably explains this consideration. The injection of botulinum toxin injection into the PES has been introduced as a replacement for CPM.

The Shaker exercise is a head lift designed to increase anterior movement of the hyolaryngeal complex and opening of the upper esophageal sphincter.

The Heimlich maneuver is used to dislodge food that the patient cannot cough out of the airway. The maneuver consists of wrapping one's arms around the upper abdomen of the victim from behind and squeezing mightily and quickly in a brief, fervent hug.

Biofeedback can be useful for oral motor and facial exercises. The patient also receives feedback on the actual swallow.

Adaptive equipment for patients who have difficulty with the motor or perceptual components of feeding compensates for decreased upper extremity functions, accommodating limited grasp, incoordination, decreased ROM, and hemiparesis. Examples include the following:

• Rocker knives

• Swivel utensils

• Built-up handles on utensils

• Scoop dishes

• Nonskid mats

• Large-handled cups

Surgery for chronic aspiration may involve the following:

• Medialization: This helps to restore glottic closure and subglottic pressure during the swallow

• Laryngeal suspension: The larynx is in a relatively protected position under the tongue base

• Laryngeal closure: This may be performed to close the glottis off, in this way protecting the airway at the expense of phonation

• Laryngotracheal separation-diversion: This procedure may be done to separate the airway from the alimentary tract

In the acute setting, when the need to decrease the aspiration of secretions is urgent, a tracheostomy is a simple and effective choice. However, in a chronic situation in which the patient has no likelihood of recovering a safe swallow and voice, laryngectomy is the most effective choice. In patients for whom recovery of voice and swallowing function is uncertain but aspiration of secretions is life threatening, temporary laryngeal closure by a diversion procedure can be used.

A tracheostomy tube worsens dysphagia by tethering the trachea to the skin and decreasing laryngeal elevation over time. To restore glottic closure, subglottic pressures, and transglottic airflow in patients with a tracheostomy, 1-way speaking valves are used. The value of the occlusion of the tracheostomy tube may be related to the provision of a closed aerodigestive tract, which enables the patient to effectively react to aspiration.

Other important benefits include improved communication, improved olfaction, and assistance with decannulation. Restoration of glottic function can also be accomplished by downsizing the standard cuffed tracheostomy tube toward stepwise decannulation.

Patients receiving mechanical ventilation often cannot control the duration of inspiratory and expiratory airflow. Therefore, ventilator settings, such as tidal volume and flow rate, may need to be adjusted during meals. (Tidal volume may need to be increased, and flow rate may need to be reduced.) The patient may have to relearn the inspiratory and expiratory phases of the breathing cycle for optimal coordination with swallowing.

Recovery from dysphagia is associated with increased pharyngeal representation in the brain, suggesting brain reorganization in recovery.

Several scales have been suggested to determine patients' functional outcomes.[66, 67, 68] One of them is the Swallowing Rating Scale (recommended by the American Speech-Language-Hearing Association [ASHA]), the categories of which are as follows:

• level 0: The patient cannot be tested

• level 1: Swallowing is not functional

• level 2: Inconsistent and/or delayed swallowing, which hinders eating and therefore prevents the patient from meeting nutritional needs; however, some swallowing is possible

• level 3: The swallowing disorder prevents eating for a portion of nutritional needs, and supervision is required for eating

• level 4: The swallowing disorder does not prevent eating to meet nutritional needs, although general supervision is required to ensure the use of compensatory techniques

• level 5: Swallowing is functional enough to meet nutritional needs, although self-monitoring and compensatory techniques are used; the patient may need occasional cueing, feeding with special techniques, and modifications

• level 6: Swallowing is functional for most eating activity, although mild difficulty may periodically occur; additional time may be necessary for eating

• level 7: Swallowing is normal in all situations

Best practice recommendations

Best practice recommendations for oropharyngeal dysphagia management in patients who have suffered acute cervical spinal cord injury (cSCI) were developed by “a 27-member panel of expert professionals in cervical spinal cord injury and complex dysphagia.” Recommendations pertained to swallowing, respiratory function, communication, nutrition, and oral care. For example, those aimed at the management of swallowing in patients after acute cSCI included the following[69] :

• A team should conduct early screening to evaluate risk factors for and symptoms of dysphagia
• Speech and language therapists should assess patients with risks for or symptoms of dysphagia, particularly those who require tracheostomy and ventilation
• To aid in the evaluation of pharyngeal and laryngeal functions, access should be available to instrumental assessments such as fiberoptic endoscopic evaluation of swallowing (FEES)
• The routine use of thickened fluids and blue dye should be avoided if not yet assessed by a speech and language therapist
• Position or ventilation status by itself should not be the basis for oral intake restriction

The goals of pharmacotherapy are to prevent complications and reduce morbidity.

Class Summary

These agents are used prophylactically to prevent complications.

Cimetidine (Tagamet)

Cimetidine inhibits histamine at H2 receptors of gastric parietal cells, which results in reduced gastric acid secretion, gastric volume, and hydrogen concentrations.

Ranitidine (Zantac)

Ranitidine inhibits histamine stimulation of the H2 receptor in gastric parietal cells, which, in turn, reduces gastric acid secretion, gastric volume, and hydrogen ion concentrations.

Famotidine (Pepcid)

Famotidine competitively inhibits histamine at the H2 receptor of gastric parietal cells, resulting in reduced gastric acid secretion, gastric volume, and hydrogen ion concentrations.

Nizatidine (Axid)

Nizatidine competitively inhibits histamine at the H2 receptor of the gastric parietal cells, resulting in reduced gastric acid secretion, gastric volume, and reduced hydrogen concentrations.

Class Summary

Proton pump inhibitors inhibit gastric acid secretion by inhibition of the H+ -K+ -ATPase enzyme system in the gastric parietal cells. They are used prophylactically in cases not responsive to H2-antagonist therapy.

Omeprazole (Prilosec)

Omeprazole decreases gastric acid secretion by inhibiting the parietal cell H+/K+-adenosine triphosphate (ATP) pump at the secretory surface of gastric parietal cells.

Lansoprazole (Prevacid)

Lansoprazole decreases gastric acid secretion by inhibiting the parietal cell H+/K+-ATP pump at the secretory surface of gastric parietal cells.

Rabeprazole (AcipHex)

Rabeprazole decreases gastric acid secretion by inhibiting the parietal cell H+/K+-ATP pump at the secretory surface of gastric parietal cells.

Pantoprazole (Protonix)

Pantoprazole decreases gastric acid secretion by inhibiting the parietal cell H+/K+-ATP pump at the secretory surface of gastric parietal cells.

Esomeprazole (Nexium)

Esomeprazole inhibits gastric acid secretion by inhibiting the H+/K+-ATPase enzyme system at the secretory surface of gastric parietal cells at the secretory surface of gastric parietal cells.