Assessments for Dysphagia
Swallowing assessments vary from subjective observations such as bedside clinical examinations to instrumental investigations which utilize medical technology. Despite the various assessments available, there is differing data with respect to variable accuracy. It is therefore recommended that a combination of assessments be used to increase accuracy. Here is a list of the assessments most commonly used in diagnosing dysphagia:
- Bedside clinical examinations - commonly used in hospitals by clinicians, nurses, and speech and language therapists requires presentation of small volumes of food or water to the patient. Upon presentation food and liquid the clinician will watch for signs of dysphagia or aspiration such as: spillage of material from mouth, poor coordination of muscles, facial weakness, delayed pharyngeal/laryngeal elevation, coughing or throat clearing, breathlessness, and changes in voice quality ("wet sounding") after swallow. The limitations that are presented with the bedside examination is that it relies on findings that are subjective and clinician dependent. (Singh and Hamdy, 2006)
- Videofluoroscopic Assessment of Swallowing (Modified Barium Swallow) - commonly referred to as the Modified Barium Swallow (MBS), the Videofluoroscopic Assessment of Swallowing entails the administration of a radio-opaque barium liquid with moving images that are captured in the lateral view of the patient's swallowing mechanism. The barium can be mixed to varying consistencies of water or may be added to other foods. The images taken with the MBS will allow the clinician to view the bolus (food or liquid) as it passes through the oral cavity, the pharynx,and oesophagus. The advantage to the MBS is the ability to visibly view any abnormal physiology, penetration, or aspiration. However, the MBS does have it's disadvantages in that the patient is exposed to a low dose of radiation, the barium density is significantly different to normal food and may not indicate the aspiration risk that may be found with other foods. (Rugiu, 2007)
- Fiberoptic Endoscopic Swallow Evaluation (FEES) - is a procedure that allows the clinician to evaluate the pharyngeal stages of swallowing with the use of a flexible fiberoptic laryngoscope. The fiberoptic laryngoscope is passed transnasally to the hypopharynx and hangs above the epiglottis so that the laryngeal and pharyngeal structures can be viewed as food passes the pharyngeal stage of swallowing. Patients are seated in a functional feeding position and given a variety of food consistencies during the evaluation. Although the FEES and MBS are similar, the advantages to the FEES are that it is cost effective, no radiation or Barium is involved, it can be used with the patient's actual meal items,there is a direct view of laryngeal function,and can be used to train patients via biofeedback. Additionally the FEES is more detailed in rendering the anatomical structures and more reliable in detecting aspiration. The sensitivy and specificity of the FEES ranges from 65% to 100% and 39% to 96%, respectively. (SDX Dysphagia Experts, 2013)
- Pulse Oximetry - is used to measure oxygen saturation which is reported to be reduced during times of aspiration. A study found that patients who exhibited aspiration or penetration by a modified barium swallow evaluation showed a significant decline in oxygen saturation thereby indicating a correlation between aspiration and/or penetration and levels of oxygen saturation. The sensitivity and specificity of pulse oximetry ranges from 73% to 87% and 39% to 87% respectively. (Sherman, et. al., 1999)
- Other Alternative Assessmants - include cervical asuscultation, radiographs, ultrasonography, manometry, scintigraphy and electromyography, however there is very little evidence for clinical use of these methods (Ramsey, et. al., 2003).
- Cervical auscultation is used to detect the presence of a swallow and aspiration by listening to the sounds of swallowing and respiration
- EGG is used to track laryngeal elevation
- Ultrasound images of the tongue and hyoid bone by using sound waves
- Pharyngeal manometry examines pressure dynamics in the pharynx and the timing of the pharyngeal contractile wave
- Scintigraphy quantifies bolus volume using ingestion of radioactive material
- EMG measures electrical activity in the muscles of swallowing