The MBSS begins, and the patient does something unusual with the first bolus that they have never done before when eating or drinking at meals. It happens all the time and for various reasons. Perhaps the patient is surprised by the taste of the barium and swallows more quickly than usual, or perhaps they are anxious or confused and hold the bolus in their mouth.
In a study by Robbins et al. (1999), the first swallow is slightly more likely to have a worse penetration-aspiration scale score measure than the second or third presentation. It is possible that this could be because our swallow response does not instantly adapt to changing conditions, and after the first swallow we adjust. Atypical occurrences with the first swallow occur regularly enough that certain swallow protocols may not have the first presentation carry much weight in determining physiology of the swallow (MBSimp included).
In today’s Modified Monday, you will see a gentleman who aspirated the first sip of thin and started coughing immediately. The facility therapist who was familiar with the patient commented, “That is really odd. He has never coughed when drinking.” The study continued, and the patient did not aspirate thin liquids again. Only a small amount of penetration was present (normal). The video shown includes all his thin liquid trials and is a perfect example of the “first swallow phenomena.”
Robbins, J.A., Coyle, J.L., , Rosenbek, J.C., Roecker, E.B., & Wood, J.L., (1999). Differentiation of normal and abnormal airway protection during swallowing using the penetration-aspiration scale. Dysphagia 14 (4): 228-232.
Martin-Harris, B., Brodsky, M. B., Michel, Y., Castell, D. O., Schleicher, M., Sandidge, J., Maxwell, R., & Blair, J. (2008). MBS measurement tool for swallow impairment-MBSImp: establishing a standard. Dysphagia, 23(4), 392-405.