What Should An Instrumental Swallow Study Report Tell You?

The purpose of an instrumental swallow study (MBS or FEES) is to look inside the oropharynx during feeding to visually and auditorily record the timed biomechanical actions required to move the food bolus efficiently and safely into the esophagus and to capture any breakdown in this process. A standardized, predetermined protocol of representative liquid and food consistencies of varying amounts is presented to stress test the mechanism.  Identifying residue, penetration, or aspiration is not the test’s primary purpose, but to determine the patient’s ability to receive hydration and nutrition. So, what information should the final report really tell you–and the medical team–about the patient’s swallowing functions?

  • Test Description: The purpose of the MBS or FEES, the number of trials tested (20+ recommended), test consistencies and amounts administered, and why, if the study is stopped before completion of the protocol.
  • Diagnosis: A documented diagnosis of normal or abnormal swallowing functions, its overall severity, and its relationship to the primary medical diagnosis, if any.
    • Example: Severe oropharyngeal dysphagia secondary to CVA.
  • Findings: A concisely written paragraph describing the efficiency of moving the bolus from the mouth to the esophagus (swallow peristalsis). Consequences of impaired swallow peristalsis are loss of bolus control and residue pooling in the pharyngeal cavities and on its surfaces. The locations holding residue should be anatomically named. Most importantly, the underlying biomechanical reasons for the residue must be given. Next, any airway protection problems (penetration and aspiration) must be described, including the number of incidences, whether the material was cleared from the airway or not, and which food consistencies were affected. Again, underlying biomechanical reasons for impairments resulting in these consequences must be described. Biomechanical improvement is always the focus of therapy.
    • Example: Impaired oropharyngeal peristalsis using nectar thick to solid food consistencies resulted in moderate residue in the vallecular spaces and mild residue in both lateral pharyngeal channels due to weak tongue force and pressure on the bolus. Penetration occurred on 5 of 20 trials and trace aspiration on three trials using thin liquid only due to reduced hyoid bone and thyroid cartilage excursion and elevation, resulting in incomplete larynx closure and seal.

The report must state the observed “consequences of impaired swallowing,”–residue, loss of bolus control, larynx penetration, and aspiration. However, these consequences are not the causes of the swallowing impairment itself.  Muscle weakness is the primary cause of swallowing impairment. It results in reduced muscle force generation, reduced pressure on the bolus, slower bolus movement, longer durations of bolus movement, and structures not moving as far as is needed to accomplish an efficient and safe swallow.  Knowing when, where, how, and the severity of these consequences directly relates to the severity of the underlying physical weakness preventing efficient and safe intake of nutrition and hydration.  This is where therapy should be focused—increasing muscle strength and timing.

  • Recommendations and Suggestions: Recommendations from the study results specify the action that is recommended based on and supported by the Findings and the Trial and Consistency Details information. You and the medical staff will provide care for the patient based on these recommendations-diet changes and allowances, water intake, medical referrals, oral care, and alternative feeding.  These recommendations are not therapy recommendations. Diet alterations are compensation techniques and ask nothing in return from the patient to improve the underlying causes of the dysphagia. Suggestions are not recommendations and may assist with your decisions in treatment. Specific therapy intervention is not given.
  • Observations: The primary purpose of the study is to assess swallowing. However, other problems may be discovered, such as masses, inflammation, edema, and may or may not interfere with the swallowing mechanism and its processes. The study should be completed regardless of these discoveries.
  • Trial and Consistency Details: A detailed description of the efficiency and safety of each and every consistency and each of the trials administered should be spelled out and the biomechanical reasons for underlying impairment.
    • Example: Thin Liquid: 3 trials (1-1/2 tsp, 2-1 tsp.). ½ tsp. was swallowed efficiently and safely. Both trials of 1 tsp splashed uncontrollably into the pharynx before the swallow and penetrated the larynx. Reflex coughing cleared the material.  Weak posterior tongue elevation and seal resulted in the loss of bolus.
  • Therapy Recommendations: The instrumental assessing SLP does not prescribe therapy for you.  Your knowledge of normal and abnormal swallow anatomy and physiology and its underlying biomechanics should allow you to understand the results of the report.  These results help to guide you in knowing what is important and what should be addressed first in treatment.  You should be able to make your own decisions based on the content of each report.

            An instrumental swallowing study is about more than aspiration. Everyone aspirates daily. You cannot prevent your patient from microaspiration, even with thickened diets or alternative feeding. Therapy is not to stop or prevent aspiration but to focus on strengthening muscles to do their job of transporting nutrition and, especially, hydration so your patients become healthier.  Diets should not be altered because of penetration test findings or out of fear the patient “might” aspirate.  Make decisions based on study evidence and not emotion or conjecture. How will your decisions alter your patient’s quality of life–eating more or eating less, good hydration or dehydration, community meals, or isolation?