Assessment of Dysphagia

Original Editor - Ewa Jaraczewska based on the course by Srishti Banerjee

Top Contributors - Ewa Jaraczewska and Jess Bell  

Introduction

A thorough dysphagia assessment can help with the early identification, management, prevention and mitigation of complications related to swallowing difficulties. It facilitates optimal nutritional support and can enhance overall patient health outcomes.

Competency training in dysphagia screening for healthcare practitioners can benefit individuals with neurological, cardiopulmonary and gastrointestinal conditions and patients post-endotracheal intubation or tracheostomy who are affected by oropharyngeal dysphagia. However, according to Freeman-Sanderson et al., less than one-third of health professionals using dysphagia protocols in intensive care units (ICU) complete formal dysphagia training.

There is also no consensus on the best screening for dysphagia, but Donovan et al. state that the "absence of consensus on the best screening instrument does not mean no screening should be performed." They advocate for dysphagia screening to be performed by a range of healthcare professionals for patients with stroke to enhance outcomes.

Dysphagia Screening

There are non-instrumental and instrumental assessments for dysphagia. Non-instrumental tests include the dry swallowing test, the water swallowing test, the 3-ounce water swallow test, the cough reflex test, and bedside swallowing evaluation. Instrumental examinations include Videofluoroscopic Swallow Study (VFSS) and Fiberoptic Endoscopic Evaluation of Swallowing (FEES). Instrumental assessments are not always available, accessible, or feasible.

For a patient who experiences dysphagia, the first and most important step is selecting the appropriate test/s.

Patient History

When taking a patient's history, the following standardised tools can be helpful:

• Eating Assessment Tool 10 (EAT 10)
  • used to screen for dysphagia and aspiration risk
  • can be completed by the patient or caregiver, or during an interview with a clinician
  • each question is rated on a scale of 0 (no problem) to 4 (severe problem)
  • the Eating Assessment Tool 10 (EAT 10) is available here
• Dysphagia Handicap Index (DHI)
  • completed by the patient
  • self-assessment questionnaire
  • includes 25 statements that assess three elements of quality of life in individuals with dysphagia: (1) functional, (2) physical, and (3) emotional
  • the Dysphagia Handicap Index (DHI) form is available here

Observation

All rehabilitation professionals should become competent to perform this part of the dysphagia evaluation. Key observation points in the evaluation of patients with dysphagia include: (1) general health status, including body mass index; (2) posture; (3) oral-motor skills (rotatory chew movement, including lateral chew, jaw jerk or suck and swallow as the patient chews); (4) inspection of the oral cavity for oral cavity ulcerations, exophytic growths, abnormal motion of the palate, mucosal drying, tongue appearance and motion, and dental status; and (5) nasal evaluation to rule out local tumours or postnasal drip.

Palpation

All rehabilitation professionals can perform this part of the assessment. While palpating, look for any tenderness, masses or swelling which could obstruct the flow of food.

Speech and language therapists (pathologists) use palpation in a clinical swallow evaluation. In the 4-finger method, one finger is placed behind the mandible, one on the hyoid bone and two on the upper and lower borders of the thyroid cartilage:

• used to assess submandibular, hyoid and laryngeal movements
• offers information about "when and how many times the patient has swallowed and a rough estimate of the timing and completeness of the swallow"

General Rules

• Determine the best seating position for a patient based on an observation of their postural strengths and needs. Look at their trunk position, shoulder alignment, and head control (e.g., an upright sitting position with hip and knee flexion might not be the best option for a patient with extreme extensor spasticity).
• Perform oral hygiene before administering water. Proper hygiene includes brushing the teeth with a toothbrush and appropriate toothpaste and rinsing the mouth with a hydrogen peroxide-based solution.

Clean water that can enter the respiratory tract while drinking is not a threat! The threat comes from food remains and bacteria that are left in the mouth due to poor, or a lack of, oral hygiene.

Neurological Assessment

• Assess the patient's arousal state and their cognitive performance
• Perform a sensory examination of the:
  • anterior two-thirds of the tongue
  • posterior one-third of the tongue
  • hard palate
  • soft palate
  • posterior pharyngeal wall
  • laryngeal region

• Complete a gross neurological examination, specifically Cranial Nerves IX to XII

Non-instrumental Dysphagia Tests

Dry Swallowing Test

All rehabilitation professionals can become competent to perform a dry swallowing test. The general steps of this test are as follows:

• the patient is positioned in a comfortable position, preferably sitting with their back and feet well-supported
• the patient's mouth can be moistened with cold water before the test
• ask the patient to swallow repeatedly
• results: three or more dry swallows during a period of 30 seconds is considered normal
• this test provides information about laryngeal elevation

Water Swallowing Test (WST)

Physicians, nurses, speech and language therapists or qualified clinicians can perform the water swallowing test:

• the patient drinks 30 mL or 100 mL of water as quickly as possible without interruption (please note that while this test is standardised, the amount of water given may vary)
• one limitation of this test is that it only assesses swallowing of water
• testing procedure:
  • the examiner observes the number of swallows
  • the average bolus size is counted by dividing 100 mL by the number of swallows
  • the swallowing speed (mL/s) is calculated by dividing 100 mL with the drinking time measured in seconds

• results:
  • >20 mL (100 mL completed with less than five swallows) is considered normal
  • the patient passes the test if they do not cough during drinking, 1 minute after drinking, or during interrupted drinking (removing the glass from the lips is considered interrupted drinking)
  • the time measurement is stopped if a patient coughs during drinking; if this happens, the swallowing speed is calculated using the amount of water the patient drank before coughing
  • additional parameters recorded are (1) wet–hoarse voice after drinking and (2) average drinking bolus size

Modified Water Swallowing Test (MWST)

Speech and language therapists or qualified clinicians who receive competency training can perform this test:

• this test includes the following steps:
  • the patient is asked to swallow 3 ml of cold water, which is usually given via syringe
  • if possible, the patient is asked to perform 2 dry (saliva) swallows

• results are scored as follows:
  • 1 = inability to swallow with choking and/or breathing changes
  • 2 = swallow occurs, but there are breathing changes
  • 3 = swallow occurs, but there is choking and/or wet hoarseness
  • 4 = successful swallow
  • 5 = successful swallow, and is able to perfom 2 additional dry swallows within 30 seconds
    • if the patient's score is 4, they should complete a maximum of 2 additional attempts (i.e. 3 total attempts)
    • the worst assessment is recorded as the final result

Bedside Swallowing Evaluation (BSE)

Speech and language therapists can perform this test:

• assesses swallowing function and airway safety during swallowing
• helps to identify the risk of aspiration
• used by speech and language therapists to provide feeding recommendations
• however, according to Moss et al., "BSEs are relatively inaccurate for the detection of aspiration"

The standardised protocol for the BSE includes the following elements:

• review of the patient’s medical record
• physical examination:
  • lip movement and seal
  • tongue movement and strength
  • volitional cough strength
  • dentition
  • voice quality
  • amount of assistance required with feeding
• the patient is positioned as upright as possible
• the speech and language therapist administers five standard consistencies: (1) ice chips, (2) nectar thin liquids, (3) pureed solids, (4) thin liquids, and (5) solids in successive boluses that get bigger each time
• all boluses are administered unless the clinician decides it is unsafe based on the patient's response
• the clinician observes five clinical signs of aspiration after each bolus: cough, throat clearing, change in vocal quality, wet breath sounds, or stridor

Cough Reflex Test (CRT)

This test is administered by speech and language therapists:

• it is a screening tool to evaluate the integrity of the cough response to airway invasion
• it can evaluate the risk of silent aspiration because it provides information about the integrity of upper airway sensation (one of the factors contributing to a patient's risk of silent aspiration)
• the patient inhales a cough-evoking mist of citric acid–physiological saline via a nebuliser to induce coughing
• the clinician records the presence, absence and number of coughs elicited and self-reported ratings of perceived intensity of airway irritation (i.e. the urge to cough)
• there is a lack of consensus in the literature on the methodology and protocols for the cough reflex test

This optional video demonstrates elements of the clinical swallowing exam:

Instrumental Dysphagia Tests

Videofluoroscopic Swallow Study (VFSS)

The videofluoroscopic swallow study (also known as the modified barium swallowing test (MBST)) is considered the gold standard in diagnosing oropharyngeal dysphagia.

• a radiographic assessment of swallowing performed by an experienced speech and language therapist with a radiologist or medical radiological technologist
• clinicians may require advanced competency certification in Videofluoroscopic Assessment of Adult Swallowing Disorders to perform this test
• "should be custom-tailored techniques designed by radiologists and swallowing therapists on the basis of the patient’s clinical history and symptoms"
• typically, a physician must initiate the request for a VFSS
• a clinical swallow assessment must be completed before a VFSS is administered

Fiberoptic Endoscopic Evaluation of Swallowing (FEES)

This assessment is administered by speech and language therapists trained in FEES examination.

• a high-cost assessment that requires appropriately trained professionals, so it might not be feasible assessment tool in all community settings
• an endoscope is passed transnasally into the pharynx in order to observe the patient swallowing saliva with and without food
• please note that this test can be feel uncomfortable / painful and each institution must develop a specific FEES protocol
• records images and sound to determine a penetration-aspiration scale (PAS) score for each of the boluses administered:
  • the PAS is an 8-point scale that is used to describe penetration and aspiration events:
    • a score of 7 indicates that material has entered the airway, passed below the vocal folds and hasn't been ejected, despite effort
    • a score of 8 indicates silent aspiration - i.e. material has entered the airway and passed below the vocal folds, but no effort has been made to eject the material
    • the full scale is available here

High-Resolution Pharyngneal Manometry (HRPM)

This test is performed by speech and language therapists with proper training in HRPM.

• used to "understand the precise mechanism of oropharyngeal dysphagia"
• it can identify those at risk for dysphagia (e.g. individuals with neurological conditions, such as Parkinson's)
• it defines pharyngeal lumen occlusive pressures, hypopharyngeal intrabolus pressures, and upper oesophagal sphincter (UES) function
• the patient doesn't need to ingest a barium bolus and it is a safe assessment for patients with dysphagia who have a high risk of aspiration
• HRPM can detect changes in swallowing-related pressures in individuals with early Parkinson's disease even before they develop signs and symptoms of dysphagia

Barium Swallow

This examination (also known as an oesophagogram) is performed by a radiologist:

• it is the gold standard test for assessing the anatomical characteristics of the oesophagus
• it evaluates oesophagal dysphagia using real-time fluoroscopy and barium
• it can help to identify any morphologic and motility abnormalities in the pharynx and oesophagus
• it is rarely used as a stand-alone investigation

Ultrasound

An ultrasound can be performed by highly skilled speech and language therapists who have completed competency training to achieve independent practitioner status:

• allows the soft tissue structures of the mouth (e.g. tongue and floor of the mouth) to be visualised
• assesses the swallowing kinematics of the tongue, hyoid, larynx, and lateral pharyngeal wall
• it also assesses displacement of the hyoid bone during swallowing
• Allows morphometric assessment (measurements of muscle thickness or cross-sectional area) of muscle groups related to swallowing, such as the tongue, masseter, and submental muscles
• it is less invasive than VFSS or FEES

Real-Time Magnetic Resonance Imaging (RT-MRI)

RT-MRI is performed by a radiologist or a radiology technologist:

• there is no radiation exposure for the patient
• it can assess the symmetry and amplitude of movements of the velum, faucial pillars, tongue, epiglottis and cricopharyngeous
• it can provide images from the sagittal, coronal and axial planes:
  • sagittal plane images can show: posterior movement of the tongue, its compression on the soft palate, hyoid bone and larynx elevation and the "lid action" of the epiglottis
  • coronal plane images can show: the symmetrical movements of the faucial pillars and the pharyngeal constrictor muscles
  • axial plane images can show: the soft palate, epiglottis and cricopharyngeous muscle - these areas are key anatomical landmarks for swallowing

Resources

• Dysphagia Ramblings
• Dysphagia Resource Collection
• 9 free swallow assessment tools
• EAT-10 swallowing screening tool in 36 languages