In Question 14 from the second paper of 2008, the college asked the candidates to "list the possible causes of an altered swallowing reflex in a critically ill patient" and discuss some strategies for assessment thereof. Furthermore, Question 2 from the first paper of 2001 asks about the effects of a tracheostomy on swallowing.
A search of Oh's Manual for "swallowing", "reflex" and "altered" reveals no page where these words might be present in a useful combination. One must therefore turn to noncanonical resources. Of these, the best - Macht's 2014 article in Chest - is now available for free. Unfortunately it does not list the possible aetiologies, as the college asked. For that, one must turn to an ancient scroll from 1981. There, one finds an etching that reads "Fig. 2. Conditions that may predispose patients to swallowing dysfunction." Together with the author's own weird ideas, the content of that figure is incorporated into the list below.
Drug-induced swallowing dyfunction:
Idiopathic miscellaneous causes:
Endocrine and metabolic causes:
Macht et al suggest several steps one should take to identify a patient as a poor swallower, and to assess the extent of their problem. With understandable abridgement, these are presented below.
One should complete an actual neurological examination before moving on with any formal assessment of swallowing. It would be embarrassing if the speech therapist made a diagnosis of MCA infarction before you did.
The ancient physiotherapist reference contains a nice step-by-step guide to this simple bedside assessment:
This simple test - when using 3 American ounces of water (about 84ml) - predicts aspiration with a sensitivity of 96.5% and a specificity of 48.7% when compared to endoscopy as the gold standard. With a high false positive rate such as this, one will frequently end up "failing" otherwise normal patients, and moving on to more detailed methods of assesment.
Realistically, this would be your next step. They go into the room, the curtains come down, something mysterious happens, and then in a few minutes the oracle emerges and brings forth a verdict.
What actually happens? An excellent article from Brazil outlines the typical speech pathologist assessment process:
The outcome of a speech therapist assessment is therefore either a recommendation regarding the type of diet to feed this patient, or a recommendation regarding further investigations, which escalate in their invasiveness.
This involves passing a 3.4-mm nasopharyngoscope through one nostril into the pharynx to view the glottis directly, with some preemptive anaesthetic/vasoconstrictor spray.
While a fluoroscopic Xray camera is watching, the patient is asked to swallow various foods and liquids. Their transit through the oropharynx and into the oesophagus is observed in real-time.
This is apparently the current gold standard of swallow evaluation. With food boluses of different viscosity, one is able to directly observe the effectiveness of intervention.
This has come up in Question 2 from the first paper of 2001, and has never appeared again. However, it has daily relevance in the pragmatic ICU sense.
A good paper from 1971 discusses this question in some detail.
In summary, the swallowing defects due to tracheostomy are as follows:
de Larminat, Valentine, et al. "Alteration in swallowing reflex after extubation in intensive care unit patients." Critical care medicine 23.3 (1995): 486-490.
Macht, Madison, et al. "ICU-Acquired Swallowing Disorders." Critical care medicine 41.10 (2013): 2396-2405.
Macht, Madison, S. David White, and Marc Moss. "Swallowing Dysfunction After Critical Illness." CHEST Journal 146.6 (2014): 1681-1689.
Zimmerman, Jack E., and Linda A. Oder. "Swallowing dysfunction in acutely ill patients." Physical therapy 61.12 (1981): 1755-1763.
Suiter, Debra M., and Steven B. Leder. "Clinical utility of the 3-ounce water swallow test." Dysphagia 23.3 (2008): 244-250.
Padovani, Aline Rodrigues, et al. "Clinical swallowing assessment in intensive care unit." CoDAS. Vol. 25. No. 1. Sociedade Brasileira de Fonoaudiologia, 2013.
Belafsky, Peter C., and Maggie A. Kuhn. "The Videofluoroscopic Swallow Study Technique and Protocol." The Clinician's Guide to Swallowing Fluoroscopy. Springer New York, 2014. 7-13.
Bonanno, P. C. "Swallowing dysfunction after tracheostomy." Annals of surgery174.1 (1971): 29.