(Chest. 2006;129:154S-168S.)
© 2006
American College of Chest Physicians
Cough and Aspiration of Food and Liquids Due to Oral-Pharyngeal Dysphagia
ACCP Evidence-Based Clinical Practice Guidelines
Carol A. Smith Hammond, PhD and
Larry B. Goldstein, MD
Correspondence to: Carol A. Smith Hammond, PhD, Durham VAMC, 508 Fulton St, No. 126, Durham, NC 27705; e-mail: smith390{at}mc.duke.edu
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Abstract
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Background: Cough may be an indicator of aspiration due to oral-pharyngeal dysphagia.
Methods: Relevant literature was identified by searching the Communication Sciences and Disorders Dome, the Cumulative Index to Nursing and Allied Health Literature, the Educational Resource Information Center, Health & Psychosocial Instruments, the American Psychological Association, and the National Library of Medicine databases from 1965 to 2004 using the terms "deglutition," "aspiration," and "cough."
Results: Aspiration was observed on radiologic evaluation in over one third of acute stroke patients and in > 40% of patients undergoing cervical spine surgery. Cough while eating may indicate aspiration, but aspiration may be clinically silent. Subjective patient and caregiver reports of cough while eating are useful in identifying patients who are at risk for aspiration. Objective measures of voluntary cough and tussigenic challenges to inhaled irritants are under investigation to determine their capacity to predict the risk for aspiration and subsequent pneumonia. The treatment of dysphagic patients by a multidisciplinary team, including early evaluation by a speech-language pathologist, is associated with improved outcomes. Effective clinical interventions such as the use of compensatory swallowing strategies and the alteration of food consistencies can be based on the results of instrumental swallowing studies. The efficacy of swallowing exercises and electrical muscle stimulation is under study. Surgical interventions may be considered in selected patients, but studies proving efficacy are generally lacking.
Conclusions: Patients who are at risk for aspiration can be identified, and appropriate interventions can reduce its associated morbidity.
Key Words: aspiration • deglutition • reflexive cough • silent aspiration • speech-language pathologist • voluntary cough
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Introduction
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Oral-pharyngeal dysphagia (ie, abnormal swallowing) may result in several complications including dehydration, malnutrition, bronchospasm, and airway obstruction, as well as aspiration pneumonia and chronic chest infection (Table 1
).123 The condition may have secondary consequences such as social isolation and depression. Cough is an important potential indicator of aspiration due to oral-pharyngeal dysphagia.2 This section will discuss the settings in which cough should prompt the consideration of a diagnosis of oral-pharyngeal dysphagia with aspiration and review dysphagia diagnosis and management. Prototypical diseases are stressed in the text focusing on neurologic and surgical conditions as other conditions have been less well-studied. Relevant literature was identified by searching the Communication Sciences and Disorders Dome, Cumulative Index to Nursing and Allied Health Literature, Educational Resource Information Center, Health & Psychosocial Instruments, The American Psychological Association, and the National Library of Medicine databases from 1965 to 2004 using the terms "deglutition," "aspiration," and "cough."
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Normal Swallow
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Normal swallowing requires the coordinated activity of the muscles of the mouth, pharynx, larynx, and esophagus, which are innervated by the central and peripheral nervous systems. Respiration and swallowing are coordinated systems that share some common anatomy and physiology. Swallowing is generally divided into phases (Fig 1
) that are modified during normal development4 due to anatomic and physiologic maturation. Swallowing in the infant consists of the suck reflex followed by oral-pharyngeal and esophageal phases that eventually mature into four phases (oral preparatory, oral propulsive, pharyngeal, and esophageal). The newborn infant is able to breathe and swallow simultaneously, an ability that is lost with maturity. The more superior location of the larynx and the shorter pharyngeal length in infancy contribute to reduced laryngeal elevation during the swallow in infants compared to adults. During postnatal development, the pharynx lengthens and enlarges, the larynx lowers, and the mandible and the hyoid descend.5 The more superior location of the larynx and the shorter pharyngeal length in infancy contribute to reduced laryngeal elevation compared to mature swallowing. For the first 3 months of life, the tongue acts as a piston within a cylinder to facilitate sucking on a nipple. The ability to form a bolus of solid food is developed as the oral pharyngeal structures mature. The tongue, lips, and mandible perform the independent functions of biting (achieved at approximately 7 months of age) and then chewing (which develops at approximately 10 to 12 months of age). As reflected by electromyography findings, children achieve an adult pattern of muscle activation during the oral and pharyngeal phases of swallowing by ages 5 to 8 years of age.4
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Figure 1. Schematic of anatomic structures and physiologic function of the normal swallow. During the oral preparatory phase, food and saliva are masticated to form a bolus. The soft palate lifts to close off the nasopharynx as the tongue slides the bolus along the hard palate. The bolus is then propelled under positive pressure into the pharynx. The duration of the pharyngeal phase is 1 to 2 s and involves a rapid sequence of events that protect the airway. The hyoid bone and larynx move upward and forward, the vocal folds move to the midline, and the epiglottis folds over the arytenoid cartilages. The tongue pushes backward and downward into the pharynx to provide positive pressure to propel the bolus. The pharyngeal walls then move inward with a progressive wave of contraction providing continuing pressure to move the bolus through the upper esophageal sphincter into the esophagus. The bolus traverses through the pyriform sinuses, which are hypopharyngeal spaces formed by the lateral pharyngeal wall and the larynx. During the esophageal phase, the upper esophageal sphincter is opened and the bolus passes into the proximal esophagus. The upper esophageal sphincter closes after passage of the bolus to prevent swallowed material from reentering the larynx. The bolus moves by a pressure wave through the esophagus.
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Developmental changes in the laryngochemo reflex also occur. Cough (one of a variety of laryngeal chemoreflexes) is elicited when hypochloremic or strongly acidic solutions contact the epithelium surrounding the entrance to the laryngeal airway. In adult animal models, the introduction of acid or water into the larynx causes coughing and swallowing, whereas the introduction of a saline solution does not elicit a cough. During the fetal or newborn periods, water in the larynx does not result in a cough; rather, it results in apnea and increased swallowing frequency.4
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Dysphagia (Abnormal Swallow), Penetration, and Aspiration
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Dysphagia is defined as abnormal swallowing due to impaired coordination, obstruction, or weakness affecting swallowing biomechanics. The terms penetration and aspiration are used to describe different degrees of abnormal airway protection that are associated with eating and drinking. Penetration occurs when material enters the laryngeal area to the level of the true vocal folds; aspiration occurs when material moves below the true vocal folds and enters the trachea.
The most dangerous time of life for fatal aspiration pneumonia is during the brief period just before and immediately after birth. Neonatal aspiration syndromes are reported in 4% of all live births and are associated with significant morbidity and mortality.67 The significant mortality rate in newborns and infants may be due to the subtle signs of aspiration (ie, apnea and increased swallowing frequency) and the lack of cough during aspiration at this stage of development.
Aspiration pneumonia is the most common form of hospital-acquired pneumonia among adults and occurs in 4 to 8 of every 1,000 patients who are admitted to hospitals in the United States. Mortality rates ranging from 20 to 65% have been reported for aspiration pneumonia.8
Several conditions may increase the incidence of dysphagia, aspiration, and pneumonia. Three studies of consecutive patients who were admitted to the hospital for acute stroke found a significant portion of material aspirated on videofluoroscopic swallow evaluation (VSE), a moving picture radiograph of the oral-pharyngeal area during swallow of solid food and liquids. In these studies, aspiration was found in 37%,9 38%,10 and 22% of patients.11 The importance of identifying aspiration was underscored by the results of a retrospective review1 of stroke patients (n = 378), which found an association between aspiration on VSE and pneumonia. Cervical spinal surgery can also increase aspiration risk.12 For example, in one study12 of 83 consecutive patients who had undergone preoperative and postoperative VSE evaluation, 42% of patients undergoing anterior cervical operations, 20% of those undergoing posterior cervical procedures, but none of those undergoing lumbar surgery aspirated after the procedure. Elderly residents of long-term care facilities are also at increased aspiration risk.13 Multivariate analysis revealed that difficulty swallowing food (odds ratio [OR], 2.0; 95% confidence interval [CI], 1.2 to 3.3) and sedative medication (OR, 8.3; 95% CI, 1.4 to 50) were the most important risk factors leading to pneumonia.13 Vergis et al14 identified witnessed aspiration and sedative medications as the most important risk factors for pneumonia in a long-term care facility. Another study15 of nursing home residents reported that bed-bound patients, reduced activity levels, reliance on others for feeding, and oral care were associated with aspiration pneumonia. Two independent predictors of pneumonia, as determined by multiple logistic regression analysis, were being fed by gastric tube (OR, 3.03; p = 0.05) and a requirement for total assistance for oral care (OR, 2.8; p = 0.03). For patients not requiring tube feedings, the likelihood of pneumonia was increased among those who were dependent for feeding (OR, 19.98; p = 0.0001), were currently smoking (OR, 4.13; p = 0.02), or were receiving more than eight medications (OR, 1.15; p = 0.02).15 Coughing in patients with abnormal oral pharyngeal swallowing suggests that aspiration has occurred, it is important to appreciate that aspiration can occur without coughing.2
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Silent Aspiration
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The term silent aspiration refers to the occurrence of aspiration before, during, or after swallowing in the absence of cough. Patients with penetration into the laryngeal area during swallow on VSE can have a fourfold increased risk of pneumonia (p < 0.008) compared to healthy control subjects. Those with more profound tracheobronchial aspiration had a total 10-fold increased risk of aspiration (p < 0.0001), and those with silent tracheobronchial aspiration had a 13-fold increased risk for developing pneumonia (p < 0.0001).8
Both male gender and age > 65 years are independently associated with silent aspiration (p = 0.017 and p = 0.003, respectively). Neurologically impaired individuals, those with GI problems, and those with unknown medical diagnoses were also more likely to silently aspirate (62%, 60%, and 64% respectively).16 Other medical conditions in which a high portion of patients have silent aspiration are indicated with by an asterisk in Table 1 
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Evaluation of Cough Suspected to be Associated With Dysphagia
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Cough and History of Aspiration
Upper airway laryngeal motor functions are important components of both cough and swallowing. Involuntary or reflexive cough (RC) in response to the presence of liquids or solid food in the laryngeal area protects against tracheobronchial aspiration. The term voluntary cough (VC) refers to a cough that is produced on command and is not related to eating or drinking. Table 2
lists the sensitivity, specificity, and, when reported, the positive and negative predictive values of both RC and VC as indicators of aspiration on VSE (the "gold standard").
The initial evaluation of patients with cough should first focus on the identification of any developmental problems, existing conditions, surgical procedures, and medications that have been associated with oral-pharyngeal dysphagia and aspiration on VSE or fiberoptic endoscopic evaluation of swallowing (FEES) [Table 1]. In addition to these conditions, dysphagia and aspiration may underlie unexplained dehydration, malnutrition, and unintentional weight loss. A combination of conditions listed in Table 3
has been associated with oral-pharyngeal dysphagia and aspiration with a sensitivity of 91% and a specificity of 47%.17
The patient, their family members, and caregivers should be questioned regarding the patient’s swallowing problems. Subjective reports by the patient or caregiver of coughing while eating and drinking or a medical history of coughing related to feeding predicts an increased risk of aspiration (Table 2). One study18 focused on a group of selected neurologically impaired patients (n = 93; mean [SD] age, 59.8 ± 16 years; range, 18 to 80 years) who had been admitted to a rehabilitation clinic over an 18-month period. The patients had a variety of conditions including stroke, brain injury, Parkinson disease, multiple sclerosis, amyotrophic lateral sclerosis, myotonic muscular dystrophy, and other neurodegenerative diseases. Subjective reports by patients of difficulty in swallowing liquids or solids, "currently or in the past," had a sensitivity of 88%, a specificity of 30%, a positive predictive value of 52%, and a negative predictive value of 75% for aspiration on VSE (the "gold standard").18
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Recommendations
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1. In patients with cough, a medical history particularly directed at identifying conditions increasing the likelihood of oral-pharyngeal dysphagia and aspiration, as indicated in Table 1, should be obtained. Patients with high-risk conditions should be referred for an oral-pharyngeal swallowing evaluation. Level of evidence, low; benefit, substantial; grade of recommendation, B
2a. Patients with cough and their caregivers should be questioned regarding perceived swallowing problems, including an association of cough while eating or drinking and a fear of choking while eating and drinking. If a patient with cough reports swallowing problems, further evaluation for oral-pharyngeal dysphagia is indicated. Level of evidence, low; benefit, substantial; grade of recommendation, B
2b. Further evaluation, including a chest radiograph and a nutritional assessment, should be considered in patients with cough or conditions associated with aspiration. Level of evidence, low; benefit, substantial; grade of recommendation, B
3. Patients with oral-pharyngeal dysphagia and cough should be referred, ideally to a speech-language pathologist (SLP), for an oral-pharyngeal swallow evaluation. Level of evidence, low; benefit, substantial; grade of recommendation, B
4. Patients with cough related to pneumonia and bronchitis who have received medical diagnoses and conditions associated with aspiration (Table 1) should be referred, ideally to a SLP, for an oral-pharyngeal swallow evaluation. Level of evidence, low; benefit, substantial; grade of recommendation, B
Physical Examination and Oral Pharyngeal Dysphagia
Patients with unexplained cough should have a thorough evaluation for potential underlying medical conditions beginning with general medical and neurologic examinations. To swallow safely, patients must be alert, awake, and able to accept food and liquids into the mouth. Extremely lethargic patients or those experiencing inconsistent levels of alertness are at increased aspiration risk.14
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Recommendation
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5. Patients with a reduced level of consciousness are at high risk for aspiration and should not be fed orally until the level of consciousness has improved. Level of evidence, low; benefit, substantial; grade of recommendation, B
For alert patients, the ability to eat and drink should be evaluated, including observation of the patient’s response to drinking water and performing a VC. Observation of the patient drinking water (a 3-oz volume) has been validated in a number of patient groups9101819 as a means of detecting dysphagia and aspiration (Table 2). The sensitivity for RC after water swallows alone further improves in the presence of other signs, (eg, wet voice, throat clear, or hoarse voice [Table 2]). Wet voice is a descriptive term for the gurgling sound produced on phonation of a prolonged "ee." A throat clear is produced by approximation of the vocal folds, which may be audible as "ahem." A hoarse voice quality or an inability to produce sound (dysphonia) after swallowing water has also been associated with aspiration. Patients with dysphagia often also exhibit dysarthria, which is characterized by slowed or slurred speech, resulting in reduced intelligibility.
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Recommendation
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6. Alert patients with cough who are in high-risk groups for aspiration (Table 1) should be observed drinking small amounts of water (3 oz). If the patient coughs or shows clinical signs that are associated with aspiration (Tables 2, 3), the patient should be referred for a detailed swallowing evaluation, preferably to a SLP. Level of evidence, low; benefit, substantial; grade of recommendation, B
VC is elicited by asking the patient to cough with as much force as possible. An abnormal VC has been described as being either "weak"910 or as "wet/gurgly."9 In one study20 of 57 patients with bilateral strokes evaluated with VSE, the majority of aspirators (21 of 25 patients; 84%) were identified by subjective evaluation to have a weak or absent VC. However, subjective evaluations of abnormalities of VC can be unreliable (Table 2).
In a study21 of selected patients (n = 30) with acute middle cerebral artery distribution stroke, the inability to cough on command (ie, VC), or absent or discoordinated phases of cough as determined by subjective assessment was labeled as "cough apraxia." Patients with left middle cerebral artery infarctions were more likely (p < 0.001) to have cough apraxia compared to those with right middle cerebral artery infarctions. However, no instrumental studies (eg, VSE or FEES) were performed, and aspiration pneumonia did not develop in any patients.21 Therefore, the clinical significance of cough apraxia remains uncertain.
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Recommendation
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7. In patients with cough, the value of the subjective assessment of VC as the sole predictor of aspiration is uncertain because of poor reliability and an unclear association with evaluation. Level of evidence, low; benefit, conflicting; grade of evidence, I
Cough Response to Tussigenic Challenges
Reduction in laryngeal sensation has been described in the elderly,22 in stroke patients,23 in patients after undergoing heart-lung transplant,24 and in patients with laryngopharyngeal reflux.25 Tussigenic challenge assesses the RC response to increasing concentrations of irritants. The threshold of concentration of citric acid to elicit the cough reflex does not appear to change with age in healthy subjects.26 Impaired cough reflex sensitivity in response to tussigenic challenges is associated with the development of pneumonia in the elderly; however, this has not as been associated with aspiration on VSE or FEES.27
Patients with laryngeal sensory system damage might be expected to have decreased sensitivity to inhaled irritants and, thus, to require increased concentrations to elicit a cough response. A reduction or absence of the RC response might place patients at increased aspiration risk. Consistent with this hypothesis, heart-lung transplant patients were found to have a significant decrease in the frequency of cough stimulated by the inhalation of distilled water compared to control subjects (0.5 vs 12.1, respectively; p < 0.001).24 The mean cough reflex sensitivity to inhaled citric acid in patients with advanced Parkinson disease (46.7 ± 49.3 g/L) was significantly lower than that for control subjects (14.5 ± 16.6 g/L; p < 0.01) and patients with early disease (11.2 ± 14.8 g/L, p < 0.005). There was no difference between control subjects and those with early disease.28 In contrast, another study29 failed to find an increased cough threshold to the inhalation of nebulized distilled water in patients with Parkinson disease compared to age-matched control subjects. In a later study,30 this same group found no difference between laryngectomized patients and age-matched control subjects for the threshold of nebulized distilled water required to elicit RC. The cough response to inhaled irritants has also been studied as a predictor of pneumonia with varying results. Cough sensitivity to the inhalation of capsaicin was evaluated in selected adult patients with a variety of neurologic impairments (n = 28) and was grouped by swallowing ability. Patients were categorized as dysphagic on the basis of swallowing speed (in milliliters per second) judged by the palpation of the cervical area during swallow without the use of instrumental swallowing evaluations (eg, VSE or FEES) to determine the presence or absence of dysphagia or aspiration. The cough threshold was not significantly different between those with normal and abnormal swallowing.31 Therefore, there is variation among studies in the usefulness of a tussigenic challenge in assessing RC related to aspiration.
Several studies have evaluated the relationship between cough sensitivity to inhaled irritants and the risk of pneumonia. Cough sensitivity to capsaicin was measured in a small consecutive group of patients (n = 7) with recurrent pneumonia (two to six episodes each), all of whom had chest radiographic findings that were consistent with aspiration.32 The concentration of capsaicin needed to induce five RCs was higher (p < 0.0001) in pneumonia patients compared to age-matched and gender-matched control subjects (mean, 2.37 mol/L [95% CI, 1.84 to 2.9 mol/L] vs 1.2 mol/L [95% CI, 1.11 to 1.47]; p < 0.0001), implying that patients with recurrent pneumonia had reduced sensitivity to foreign material in the laryngeal area.32 The incidence of pneumonia was also studied in a cohort33 of consecutive nursing home patients who had been admitted after stroke (n = 143). The subjects were > 65 years of age and were grouped according to the following classifications: oral feeding without dysphagia (n = 43); oral feeding with dysphagia (n = 48); nasogastric tube feeding with dysphagia (n = 52); or nasogastric tube and bedridden (n = 14).33 The swallowing reflex was assessed as the latency of the response to swallow after the injection of 1 mL of water into the pharynx through a nasal catheter. The cough threshold to citric acid aerosols was defined as the concentration at which the patient coughed five times. Abnormal responses were defined as a swallow response longer than 5 s and a cough threshold to citric acid concentrations of > 1.35 (log mg/mL). The incidence of pneumonia (24 of 143 patients) was higher in patients with oral feeding (19 of 35 patients) than in those with tube feeding (54.3% vs 13.2%, respectively; p < 0.001). Bedridden patients with tube feeding had a swallowing latency of > 20 s, no patient coughed at the highest concentration of citric acid and the incidence of pneumonia in this group was 64.3%.33 However, it is not clear how much the assessment of RC added to the patient’s known clinical aspiration risk factors.
Pneumonia rates were compared between patients assessed by an SLP in an acute rehabilitation hospital with the use of a cough reflex test and by an SLP assessment without use of the cough reflex test.34 The cough reflex test used a 20% solution of prescription-grade l-tartaric acid, which was dissolved in 2 mL of sterile normal saline solution. The solution was placed in a nebulizer and was inhaled as a microaerosol. In the hospital using the cough reflex test, 1.25% of stroke patients (n = 400) developed pneumonia compared to 13.2% of stroke patients in the institution that did not use the cough reflex test (n = 204). However, conclusions are limited because the patients were not randomized and no data were provided to assess the comparability of the groups or their treatments.
Cough reflex sensitivity to citric acid was also measured in elderly nursing home patients who were randomly assigned to receive intensive oral care (n = 30) and usual oral care (n = 29). Cough reflex sensitivity after 30 days of intensive oral care was significantly higher than at baseline (p < 0.01) and was comparable to that in the control group (p < 0.05).35 The implications of this observation for patient care are uncertain.
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Recommendation
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8. The assessment of the RC response to inhaled irritants as a predictor of aspiration risk and subsequent pneumonia is not recommended due to a lack of adequate supportive studies. Level of evidence, low; benefit, conflicting; grade of evidence, I
Aerodynamic Measures of Cough
Objective aerodynamic measures of VC were studied in a group of selected patients (n = 43) who had been admitted to the hospital with acute hemorrhagic or ischemic stroke.36 Based on the results of VSE or FEES (the "gold standard"), patients were categorized into three groups: (1) mild aspirators (n = 17), if aspiration was observed for thin liquids and Ensure (Abbott; Abbott Park, IL) only; (2) severe aspirators (n = 11), if there was aspiration of all liquid consistencies (thin liquids, Ensure, and thickened liquids); and (3) nonaspirators (n = 15). There were 15 age-matched and gender-matched control subjects with no history of stroke or dysphagia. The Canadian Neurologic Stroke Scale was used to determine stroke severity.37 There was no difference between groups for age, gender, or the presence of pulmonary disease. All VC measures were abnormal in stroke patients compared to control subjects (each p < 0.05) [Fig 2
]. Univariate analysis showed that VC peak flow of the inspiration phase, sound pressure level, peak flow of the expulsive phase, expulsive phase rise time, and VC volume acceleration (peak flow expulsive phase/expulsive phase rise time) were significantly different in nonaspirators compared to both severe and mild aspirators (Fig 2). Multivariate logistic regression revealed that only expulsive phase rise time values during cough independently correlated with aspiration status (p < 0.001), with no additional contribution by stroke severity or other VC variables. Respiratory function, VC expulsive phase peak flow, and sensitivity to inhaled citric acid were also compared between patients with early-stage and late-stage Parkinson disease and age-matched control subjects.28 No differences were found for age, height, FVC, and FEV1. The mean peak expulsive phase flow for VC was weaker both in patients with early-stage Parkinson disease (230 ± 74 L/min; p < 0.005) and in those with advanced-stage disease (186 ± 60 L/min) compared to control subjects (316 ± 70 L/min; p < 0.0001), but not between the groups of patients with Parkinson disease.28
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Figure 2. Examples of airflow records from healthy subjects (top left, 1) and stroke subjects (top right, 2, bottom left, 3, and bottom right, 4) during VC. Zero airflow is depicted as a horizontal dotted line. All phases of VC are illustrated as follows: inspiration phase, A to B; compression phase, B to C; expulsion phase rise time, C to D. Control subjects were significantly different from stroke patients as a group for all cough measures (p < 0.001). Note the increased expulsion phase rise time in aspirators (bottom left, 3, and bottom right, 4) compared to stroke patients who did not aspirate (top right, 2).
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Aerodynamic measures of VC have also been studied38 in patients with motor neuron disease (n = 53). Cough spikes are transient increases in expiratory flow above the maximal expiratory flow-volume curve. In this study,38 patients with cough spikes were significantly more likely to be alive 18 months after undergoing baseline tests (p < 0.05). Two thirds of the survivors (12 of 18 survivors) had cough spikes compared to 34% of those who died.38
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Recommendation
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9. In acute stroke patients, the expulsive phase rise time of VC may predict aspiration. The use of this test has not been validated in other patient groups, and further studies comparing the accuracy of objective measures of VC to the clinical swallow evaluation to identify aspiration risk are needed. Level of evidence, low; benefit, small; grade of recommendation, C
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The Roles of SLP, VSE, and FEES
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The American Speech Language and Hearing Association position statement39 includes oral-pharyngeal dysphagia in the scope of practice for the SLP, and provides guidelines for the knowledge and skills needed by the SLP for the evaluation and treatment of swallowing disorders.40 The evaluation by the SLP includes a clinical swallowing ("bedside") examination as well as the use of dynamic imaging techniques during the oral and pharyngeal phases of swallow (ie, VSE or FEES. In some medical centers, occupational therapists may also be trained in dysphagia management. The US Agency for Healthcare Research and Quality41 reported that the implementation of programs to screen acute stroke patients for aspiration and dysphagia, and to refer patients with apparent problems to dysphagia specialists for evaluation and treatment resulted in a dramatic reduction in the rate of aspiration pneumonia.
Typically, the clinical swallow evaluation relies on the clinician’s subjective judgments, while the VSE and FEES provide direct visualization of the anatomy and physiology of swallowing during deglutition. The VSE is a motion picture radiograph of the bone, cartilage, and soft tissue swallowing structures visualized as the food and liquid mixed with barium passes through all stages of the swallow. The patient is observed in the lateral and anterior-posterior positions.5 FEES can be performed at the bedside or in a clinic area and involves the transnasal passage of a flexible nasopharyngoscope to provide direct observation of the pharynx and larynx before and after the swallow.42 The addition of an instrumented swallow evaluation (VSE or FEES) would only need to result in a reduction in the rate of pneumonia by 10% (absolute difference, approximately 0.8%) to fully offset the expense of the tests (based on Medicare reimbursement rates at the time of the report). At least this much improvement is reasonable to expect, considering the rate of detection of silent aspiration not expected on the clinical swallow evaluation.41
One very important advantage of imaging swallow studies is their use not only for diagnosis, but to determine which therapeutic technique will eliminate aspiration during oral eating and drinking. Staffing limitations, economic constraints, and the lack of availability of VSE or FEES often place the clinician in a position of dependence on the clinical swallow evaluation alone.
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Recommendation
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10. Patients with dysphagia should undergo VSE or FEES evaluation of swallow to identify appropriate treatment (reviewed below). Level of evidence, low; benefit, substantial; grade of recommendation, B
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Treatment
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General Management of Patients With Oral-Pharyngeal Dysphagia
The goal of treatment of patients with cough due to oral-pharyngeal dysphagia is to eliminate the penetration of food and liquids into the laryngeal area and their aspiration below the level of the true vocal folds. The guideline of the American Gastroenterological Association on oral pharyngeal dysphagia management43 recommends a multidisciplinary approach due to the complexity of the disorder, and noted the need to design and test therapy on an individual-patient basis. The adoption of a stroke clinical practice analysis program44 led to a more uniform, evidence-based treatment of acute stroke patients at one facility in which aspiration pneumonia was the leading cause of stroke-related morbidity and mortality. A proactive team consisting of a neurologist, a nurse, occupational, physical, and speech therapists, a pharmacist, a dietitian, and a discharge planner were responsible for stroke patient care including assessment by an SLP within 24 h of hospital admission. The program resulted in a significant decrease in the rate of aspiration pneumonia from 6.4 to 0% (p = 0.03), an overall decrease in unadjusted costs from $7,111 to $6,246 (p = 0.001), and an associated trend for decrease in the stroke mortality rate from 11 to 4.6% (p = 0.063).45
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Recommendation
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11. Patients with dysphagia should be managed by organized multidisciplinary teams that may include a physician, a nurse, an SLP, a dietitian, and physical and occupational therapists. Level of evidence, low; benefit, substantial; grade of recommendation, B
Compensatory Maneuvers
The goals of dysphagia therapy focus on the reduction of aspiration, improved swallowing ability in order to optimize nutritional status, and quality of life. Techniques have been developed to improve the opening of the upper esophageal sphincter, to increase pharyngeal clearance, and to minimize aspiration. These compensatory maneuvers can be used if the patient’s cognitive status is appropriate for training. The effect of maneuvers on aspiration was studied46 in consecutive patients who had been referred for dysphagia management (n = 165) with a variety of diagnoses. When aspiration occurred, the patient was instructed to perform one of the following postures: to chin-down, chin-up, head-rotated, head-tilted, or lying down. With the use of postural maneuvers, aspiration was eliminated during the VSE in 127 of the patients (77%).46
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Recommendation
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12. In patients with dysphagia, VSE or FEES can be useful for determining compensatory strategies enabling patients with dysphagia to safely swallow. Level of evidence, low; benefit, substantial; grade of recommendation, B
Dietary Modification
Specific recommendations for liquid consistency can also be made based on the results of the VSE or FEES. The administration of solid foods and liquids commonly available to the patient should be administered during VSE or FEES to determine which consistencies of these substances can be swallowed without risk for aspiration. Studies in adults and children have shown a dramatic reduction in the aspiration of thickened liquids compared to thin liquids. In patients with acute stroke (n = 745) who had been referred for VSE in which liquids (ie, thin, nectar thick, and ultra-honey-thick) under two methods of delivery (spoon and cup drinks) were administered, aspiration was more common with use of the cup vs use of the spoon (p < 0.001), was more frequent for thin liquids (eg, soda and coffee) than for nectar-thick liquids, and were more frequent for thick liquids than for ultra-honey-thick liquids (p < 0.001).47 Another recent study48 of adult patients found a reduction in airway protection with straw drinking in older healthy subjects compared to young healthy subjects, indicating a need to include straw drinking, which is a commonly used method for the delivery of liquids in the elderly, during instrumental evaluations. In infants with bronchiolitis, dramatic reductions in the occurrence of aspiration were observed on VSE for thick liquids compared to thin liquids.49
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Recommendation
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TOP
Abstract
Introduction
