List the possible causes of an altered swallowing reflex in a critically ill patient, and outline how you would assess this.

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College Answer

Swallowing is a complex reflex and requires an oral preparatory phase, and oral voluntary phase, a pharyngeal phase and as oesophageal phase. A myriad of potential causes exist. Possible causes of altered swallowing include: drug induced (eg. anti-cholinergic, neuroleptics), mechanical (eg. trauma from Trans-Oesopgageal Echocardiography or endotracheal intubation; presence of tracheostomy; rarely pre-existing structural problems eg. diverticula/pouches), infectious (eg mucositis), metabolic (eg. thyrotoxicosis), myopathic (eg. specific or non-specific neurological syndromes effecting bulbar function) and neurological (eg. stroke, severe head injury, Guillain-Barre syndrome etc.). Assessment is via history (previous problems, recent procedures and medications) and examination (local mechanical and bulbar neurological problems, systemic diseases and
systemic neurology). Specific procedures may involve watching attempts at swallowing (eg. speech therapist ± dye or different consistencies of food, looking for signs of aspiration
etc.), or more sophisticated techniques including naso-endoscopy (mainly anatomic assessment), and video-fluoroscopy or barium swallow (both providing a functional assessment).

Discussion

This question closely resembles Question 14 from the second paper of 2008.