A swallow test is a diagnostic tool used to objectively evaluate the physiological process of swallowing in individuals suspected of having dysphagia (difficulty swallowing). This complex process involves a coordinated effort among muscles and nerves in the mouth, throat, and esophagus. The primary goal of a swallow test is to pinpoint where the breakdown in this coordination is occurring and to assess the safety of the patient’s swallow. Speech-Language Pathologists (SLPs) typically conduct and interpret these evaluations. The results guide the medical team in creating a management plan to ensure the patient can eat safely and maintain adequate nutrition.
Identifying the Symptoms That Require Testing
A physician orders a swallow test when a patient reports symptoms suggesting a problem with swallowing. Common indicators include coughing or choking during or immediately after meals, which suggests food or liquid may be entering the airway. Patients may also describe the sensation of food feeling “stuck” in the throat or chest (globus sensation) or experience pain while swallowing (odynophagia).
Untreated swallowing difficulties pose serious health risks. When material enters the airway, it is called aspiration, which can lead to recurring respiratory infections like aspiration pneumonia. Dysphagia also compromises a person’s ability to consume sufficient calories and hydration, often resulting in weight loss and malnutrition.
The Primary Diagnostic Methods
Two primary instrumental evaluations are considered the gold standard for assessing the mechanical aspects of swallowing. The Modified Barium Swallow (MBS), also known as a Videofluoroscopic Swallow Study (VFSS), is a dynamic X-ray procedure. During this test, the patient swallows different consistencies of food and liquid mixed with barium, a radiopaque substance that shows up clearly on the X-ray screen. This allows the clinician to view the entire swallowing process in real-time, from the mouth through the pharynx and upper esophagus.
The MBS is particularly effective for observing the four phases of the swallow and detecting two serious events: penetration and aspiration. Penetration occurs when material enters the top of the airway (the larynx) but remains above the vocal cords, while aspiration means the material has passed below the vocal cords and into the trachea. The study also helps identify anatomical issues and the location of residue, such as material lingering in the valleculae or pyriform sinuses after the swallow. However, because it uses X-ray technology, the duration of the test is limited to minimize the patient’s radiation exposure.
The second common test is the Fiberoptic Endoscopic Evaluation of Swallowing (FEES), which involves passing a thin, flexible endoscope through the patient’s nose to view the back of the throat and larynx. The clinician observes the structures before and after the swallow, sometimes using food and liquid mixed with colored dye to enhance visibility. A major advantage of FEES is its portability, allowing it to be performed at the patient’s bedside without a radiology suite, and it involves no radiation exposure, meaning it can be safely repeated.
While FEES offers a close-up, high-definition view of the pharynx and larynx, the view is briefly blocked when the pharyngeal muscles contract during the swallow itself, known as the “whiteout” period. Unlike the MBS, FEES cannot visualize the oral phase or the entire length of the esophagus, making the choice of test dependent on the specific swallowing phase the clinician suspects is impaired. Both procedures are generally completed quickly, often within 15 to 30 minutes.
Preparing for the Evaluation and Interpreting the Findings
Preparation for a swallow test varies depending on the specific procedure. For an MBS, patients are often instructed to stop eating and drinking for several hours before the test to ensure the digestive tract is clear. Patients should also inform the medical team of all medications and any known allergies to contrast agents.
The findings from the instrumental evaluation translate directly into a comprehensive management and treatment plan. The SLP analyzes the data to determine the severity of the dysphagia and identifies specific physiological problems, such as poor tongue base retraction or delayed pharyngeal constriction. This information is used to create therapeutic recommendations, which may include swallowing exercises designed to strengthen weakened muscles or improve coordination.
Test results also inform immediate dietary modifications to improve swallowing safety. If the patient is found to aspirate thin liquids, the SLP may recommend thickened liquids or a change to pureed or soft solid foods. The plan may also include compensatory strategies, such as specific head postures or swallowing maneuvers, that the patient can use during meals to reduce the risk of aspiration.