Cough Reflex Testing following Stroke: Development of a clinical pathway

Upon inclusion in the study, all participants will receive an oromotor examination assessment to evaluate the function of the muscles and structures used for swallowing, as per routine speech pathology practice. Cough reflex testing Group: Following the initial oromotor assessment, all participants randomly allocated to receive the cough reflex testing will undergo cough reflex testing according to the procedure that was developed by Miles et al (2013). Details of this procedure are as follows: 1. Administration procedure Participants will be seated upright in a bed or chair. A total volume of 3ml of citric acid (which is diluted by the pharmacy department in 0.9% sodium chloride, to obtain a concentration of 0.6M) will be administered for a maximum of 15 seconds via a facemask using a nebuliser or medical air (not oxygen) with a predetermined free-flow \output of 7L . A sterile facemask and tubing will be provided for each participants. The assessing speech pathologist will say to the participant, “I’m going to give you some air to breath, keep breathing normally”. The test is repeated three times with a 30-60 second rest interval between each presentation. Cough evaluation The speech pathologist will record the strength of each cough response using the following criteria: Strong Two or more strong coughs Weak Two or more weak coughs Absent One or no cough Criteria for positive or negative response to cough reflex testing include: Positive result Two strong cough responses out of three trials Positive but weak result Two weak cough responses out of three trials Negative result Two absent responses out of the three trials Clinical pathways following cough reflex testing There are three pathways that will be followed, depending on the outcome of the cough reflex testing. (1) If the patient produces a positive result, the clinician will then proceed with an oral trial of food or fluid as part of the initial assessment. (2) If the patient produces positive but weak results, the clinician will proceed with oral trial of food or fluid in the intial assessment but will also refer the patient for a video-fluroscopic swallowing study (VFSS) as soon as possible (this may vary depending on when the clinic has an available appointment), as bedside indicators of aspiration may be inaccurate (i.e., patient may be silently aspirating). (3) If the patient produces a negative result, the clinician will not proceed with oral trials and will refer the patient for a VFSS prior to any oral trials, as bedside indicators of aspiration are likely to be inaccurate, with the patient having a high risk of silent aspiration. Documentation The cough reflex test will be documented on the patient’s medication chart, as follows: Citric Acid 3 ml 0.6M solution via nebulizer per speech pathology cough reflex procedure ‘signature’ ‘date’ ‘printed name’. The cough reflex test results will also be included speech pathology assessment notes in the electronic medical record (eMR). 2. Video-fluroscopic swallowing study As per the aforementioned clinical pathways, patients who either fail the cough reflex testing or have a weak result will be referred for an objective instrumental assessment of swallowing via VFSS. The VFSS is a dynamic x-ray that permits the visualisation of bolus flow in relation to structural movement throughout the upper aero-digestive tract in real time. The VFSS also permits detection of the presence and timing of aspiration, i.e., entry of material below the level of the true vocal folds into the trachea, and assists in identifying the physiological and often treatable cause(s) of the aspiration. Furthermore, an VFSS allows clinicians to observe the effects of various bolus volumes, bolus textures, and compensatory strategies on swallowing physiology. If patients are not able to access a VFSS due to unforseen mechanical breakdown, the cough reflex testing procedure will be repeated on the next day and data will be analysed separately.