Validating Cough Reflex Testing Against Instrumental Assessment Of Aspiration And Laryngeal Sensation.

This is a prospective single blinded cross over correlational study. The aim of this stage is to validate the cough reflex test against previously validated instrumental measures of aspiration and penetration and laryngeal sensation (with the use of flexible naso-endoscopic assessment). All participants will undergo 2 assessments; cough reflex testing and instrumental swallowing assessment. Both these tests are already in place at the research site for use with this patient group. Different independent researchers perform each test and will be blinded to the result of the alternate test. The tests were alternated in randomly. Cough reflex testing takes 10 minutes approximately. Citric acid concentrations are administered for 15-seconds via facemask using PulmoMate Compressor/Nebuliser (Model 4650I, DeVilbiss Healthcare LLC, Pennsylvania, US) with a predetermined flow output of 8 litres per minute. Patients are asked to breathe normally and cough “if they feel the need to cough”. Initially a placebo dose of 0.9% NaCl is presented to coach the patient on task completion. Citric acid concentrations are administered incrementally from low to high in 1-minute intervals. A placebo dose is interdispersed between each change in citric acid dose to prevent tachyphylaxis and blunting of lower doses. Presence or absence of cough during the 15-second delivery period is documented. VFSS assessment take place in the radiology suite. Patients are administered a standard protocol of volumes and consistencies of barium constrast agent and the procedures takes 10 minutes approximately. FEES was performed at the patient’s bedside using a 3.2 mm diameter flexible video rhino-laryngoscope (ENF- V2, Olympus Corporation, Tokyo, Japan), an integrated light source and video processor (Olympus, OTV-SI, Olympus Corporation) and LCD Monitor (Olympus OEV203, Olympus Corporation). No topical anaesthesia was used. The endoscope was passed through the nose and positioned in the pharynx. Again a protocol involving a variety of foods and drinks are given. Aspiration is noted.