74 Dysphagia & Aspiration Flashcards
How do you define normal swallowing?
How do you define normal swallowing?
Normal swallowing is divided into phases: (a) the preoral anticipitory phase, (b) the oral preparatory phase, (c) the oral transport phase, (d) the pharyngeal phase, and (e) the esophageal phase.
- Preoral anticipitory phase: This phase begins with seeing, smelling, and tasting food. When our senses are triggered we produce saliva which is designed to make chewing food easier.
- Oral preparatory phase: After food enters the oral cavity it is manipulated by the tongue, lips, cheeks, palate, and jaw. The masticated food is formed into a bolus by the tongue in preparation for swallowing.
- Oral transport phase: The transport phase of a swallow involves propelling the bolus back along the palate until the bolus reaches the anterior tonsillar pillars. At this point, a swallow reflex is initiated and the oral phase of swallow is concluded. A normal oral phase is approximately 1 second, even with differing food consistencies, age, or sex of the individual.
- Pharyngeal phase: The pharyngeal phase of a swallow is initiated after the swallow reflex occurs. The pharyngeal phase of a swallow involves four main neuromotor components: (a) velopharyngeal closure to prohibit oral contents from entering the nasal cavity, (b) peristaltic contraction with the pharyngeal constrictors moving the bolus through the pharynx, (c) airway protection via laryngeal elevation and laryngeal closure to prevent aspiration, and (d) upper esophageal opening to allow the bolus to pass from the pharynx into the esophagus.
- Esophageal phase: The esophageal phase of a swallow occurs when the bolus has passed through the upper esophageal sphincter at the base of the pharynx. The bolus is then carried through the esophagus via peristaltic movement of the constrictor muscles of the esophagus.
Define dysphagia.
Define dysphagia.
Dysphagia is the symptom of difficulty in swallowing, usually as a result of nerve or muscle injury, that can occur at different phases within the swallowing process as described above.
What are the most common causes of dysphagia?
What are the most common causes of dysphagia?
Dysphagia is generally caused by either a neurologic and/or anatomic injury usually occuring from a disease of the cerebral cortex and brainstem, cranial nerves, and/or muscles of swallowing. Cerebral vascular accident (CVA) is the most common neurologic cause of dysphagia. If only a single cerebral hemisphere is affected by CVA, swallowing can be preserved because the brainstem still receives input from the other, noninjured hemisphere.
Dysphagia can occur in any phase of the swallow. In the oral prepatory phase, swallowing is controlled by both the cortex and the brainstem and is voluntary (i.e. not a reflex). Disorders in the oral phase include decreased lip closure, decreased buccal tension, decreased strength and/or coordination in the musculature needed for adequate mastication, and decreased tongue range of motion and coordination. The pharyngeal phase of swallowing is an involuntary phase that is controlled by the brainstem. Pharyngeal phase impairments can include a delayed swallow reflex; decreased velopharyngeal closure resulting in nasal regurgitation, decreased epiglottic retroflexion, and laryngeal elevation thus increasing risk for airway exposure during the swallow; and damage to the opening and closing of the upper esophageal sphincter, which limits the ability to successfully pass the bolus to the esophagus.
How is dysphagia typically diagnosed?
How is dysphagia typically diagnosed?
There are three techniques widely used to diagnose dysphagia: (a) bedside swallow evaluation, (b) fluoroscopic examination called a modified barium swallow (MBS), and (c) fiber-optic endoscopic evaluation of swallowing (FEES). Although bedside tests are safe, relatively straightforward, and easily repeated they have variable sensitivity and interrater reliability. They are also poor at detecting silent aspiration. Modified barium swallow studies allow a real time view of both anatomic and physiologic function. Modified barium swallow tests also allow testing of different swallow techniques to decrease the presence of penetration/aspiration. Fiber-optic endoscopy allows swallow assessment and sensory testing but requires specialized equipment.
How do you define penetration and aspiration?
How do you define penetration and aspiration?
Whether a swallow has been triggered or not, the main path of any food or liquid should be directed toward the esophagus. However, when food or liquid is misdirected into the laryngeal vestibule but stays above the level of the true vocal cords, this is referred to as “penetration.” If penetration into the laryngeal vestibule occurs during swallowing but clears with no residue once swallowing is complete, it is known as “transient” penetration. Aspiration occurs once material has dropped below the level of the true vocal cords and airway protection has been compromised. “Silent” aspiration indicates that material has dropped below the level of the true vocal cords, without any overt signs and symptoms of aspiration (i.e., coughing, throat clearing, etc.).
What are the steps involved in a bedside swallowing evaluation?
What are the steps involved in a bedside swallowing evaluation?
A bedside swallow evaluation is a screening process used by speech-language pathologists (SLPs) to assess dysphagia. The purpose is to determine the etiology of dysphagia, assess the patient’s ability to adequately protect the airway, assess the possibility of oral feeding, recommend alternative means of nutrition management if needed, assess the need for additional diagnostic tests or referrals, and establish baseline function versus current level of function. SLPs look for signs or symptoms of possible oral or pharyngeal dysphagia when given oral trials. A thorough exam will include a comprehensive chart review, oral motor assessment, assessment of vocal quality, strength of cough, anterior-posterior transport of material, pharyngeal constriction, hypolaryngeal excursion, laryngeal elevation, and assessing overt signs and symptoms of penetration and/or aspiration. When results are inconclusive, an SLP will often perform a more objective measure (MBS or FEES) to further evaluate swallowing function.
For a patient with a tracheostomy tube, a bedside swallowing evaluation will begin with cuff deflation and finger occlusion to first determine the patient’s ability to move air around the tracheostomy tube and the vocal cords and into the oral and nasal cavities. If no difficulty is observed, an SLP will place a Passy Muir valve (PMV) prior to performing PO trials to increase subglottic pressure and allow for increased airway protection. Food and liquid are often dyed blue to check for aspiration (see Question 8).
What do signs and symptoms of penetration/aspiration look like at the bedside?
What do signs and symptoms of penetration/aspiration look like at the bedside?
Clinicians utilize a variety of symptoms and signs as indicators of oral-pharyngeal dysphagia and subsequently penetration/aspiration. These include coughing, wheezing, recurrent pneumonia, gagging, choking, chest congestion, tachypnea, bradycardia, oxygen desaturations, noisy or wet breathing, delayed swallows, and vocal changes. Additionally, signs such as gurgly respiration or wet vocal quality can be associated with hypopharyngeal or laryngeal pooling of secretions or pharyngeal residue of food materials.
What is a blue dye test and what is the purpose of its use?
What is a blue dye test and what is the purpose of its use?
The modified Evan’s blue dye test (MEBDT) is a simple and inexpensive way of assessing aspiration in the tracheotomized patient. Blue dye is placed in food and liquids provided to the patient during a bedside assessment. The patient is deep suctioned to see if any blue material has entered the airway. If nothing is recovered during procedure and assessment, the SLP will wait 24 hours for evidence of delayed aspiration before allowing oral intake and notify both nursing and respiratory therapy that a MEBDT has been provided. Sensitivity of the MEBDT in predicting aspiration among individuals in one specific study was 82%; however, this test can provide a false negative result, therefore the absence of of blue dye does not automatically guarentee a patient is not aspirating.
What portion from an “oral mechanism exam” provides the most insight into a person’s risk for aspiration?
What portion from an “oral mechanism exam” provides the most insight into a person’s risk for aspiration?
The goal of an oral mechanism examiniation is to provide information regarding structures, structural relationships, movement function of the tongue and lips, and to identify sensory function within the immediate extra- and intraoral structures. Studies have shown that incomplete lingual range of motion will make a person more likely to aspirate than those with complete lingual range of motion, regardless of complete labial closure and intact facial symmetry. Identifying oral motor weaknesses will raise a heightened awareness during the bedside swallowing assessment.
How do tracheostomy tubes and one-way speaking valves impact a patient’s risk for aspiration?
How do tracheostomy tubes and one-way speaking valves impact a patient’s risk for aspiration?
In tracheostomy patients, there is a high incidence (50% to 87%) of aspiration and pneumonia. Many studies have looked at the incidence of aspiration with open and closed tracheostomy tubes, and found that with the use of finger occlusion or an obturator the incidence of aspiration was significantly reduced in comparison to those with an open tracheostomy tube. Similarly, the use of one-way valves to occlude the tracheostomy tube has been found to significantly reduce the incidence and severity of aspiration of thin liquids. One reason for the reduction in aspiration is that the one-way valve increases subglottic air pressure and activation of mechanoreceptors, which are lost when the tracheostomy tube is open. Additionally, improved sensation may also increase the patient’s ability to expel material through the throat by coughing and/or throat clearing.
FEES vs. MBS—which test is “better”?
FEES vs. MBS—which test is “better”?
Both evaluations provide visualization of the swallow mechanism including the pharynx and larynx. A FEES is portable to the bedside for patients who are difficult to position/transport due to size. Additionally, you are able to test real food items and for full meal duration. With an MBS, you have a view of oral, pharyngeal, and esophageal phases of a swallow. You are limited to small amounts of food mixed with barium in different consistencies. You are unable to view the soft tissues or the pharynx/larynx. It is an assessment that is of very short duration and is not sensitive to the effect of fatigue on the swallowing mechanism. Additionally, it is dependent on radiology scheduling which limits the flexibility of the procedure.
What is the Penetration Aspiration Scale and why is it so widely used during MBS?
What is the Penetration Aspiration Scale and why is it so widely used during MBS?
The Penetration Aspiration Scale (PAS) is an 8-point scale that was developed to provide an objective and consistent way to evaluate a persons penetration and/or aspiration during a MBS. It is widely used due to its favorable intra- and interrater reliability and the ability to easily track outcomes according to changes made on the PAS (Table 74-1).
What is the 3-oz water test and is it effective in determining risk for aspiration?
What is the 3-oz water test and is it effective in determining risk for aspiration?
The 3-oz water swallow test is a screening tool that is used to identify patients who are at risk for clinically significant aspiration and who will require a more objective swallow evaluation. Individuals are required to drink 3 ounces of water without interruption. If they cough, choke, or show a wet-hoarse vocal quality during the test or for one minute afterward, they are considered to have failed. This test relies on overt signs and symptoms of aspiration, but most specifically the cough reflex to determine a patient’s risk for aspiration; therefore it is weak in its ability to detect silent aspiration. In recent studies, the 3-oz water swallow test was able to identify 80% of patients aspirating compared to a subsequent videofluoroscopic modified barium swallow examination. It more easily identifies patients with severe dysphagia aspirating larger amounts or thicker consistencies of test material.
What is the incidence of dysphagia following intubation?
What is the incidence of dysphagia following intubation?
Literature has shown that pharyngeal muscle atrophy begins after 24 hours of intubation. However, literature regarding dysphagia frequency following endotracheal intubation is variable, ranging from 3% to 62%. In a recent study, the highest incidence of dysphagia was seen in patients experiencing intubation longer than 24 hours. Age greater than 55 years, medical comorbidities, and a prior history of dysphagia were also found to increase a person’s risk for aspiration following intubation.
Why are infiltrates seen in the RLL more indicative of an aspiration pneumonia?
Why are infiltrates seen in the RLL more indicative of an aspiration pneumonia?
Aspirated material is drawn to gravity-dependent portions of the respiratory system, especially since most patients are sitting in an upright position when eating and drinking. The right main stem bronchus is more vertically positioned in most adults than the left, hence the attribution of right lower (or middle) lobe pneumonias to aspiration and dysphagia.
Are there medications that are more likely to cause dysphagia?
Are there medications that are more likely to cause dysphagia?
Medication-induced dysphagia is far more common than reports in medical literature suggest. When dysphagia occurs as a side effect of a medication it is usually caused by decreasing muscle function, coordination, and/or sensation needed for swallowing. Additionally, medications that cause dry mouth (xerostomia) can interfere with swallowing by impairing the ability to transport food in the mouth. A list of such medications is provided in Table 74-2.
The therapeutic effects of medications can also contribute to dysphagia. When used over a long period of time and in high doses, some medications can cause muscle deterioration resulting in dysphagia. A list of such medications is in Table 74-3.
