The effects of a clinical care protocol on patient outcomes in an acute stroke population

Patients with acute stroke and dysphagia who are referred for swallowing assessment will be managed under current clinical care protocols. These include a cranial nerve exam, informal assessment of cognition and communication, and cough reflex testing. If a patient passes the cough reflex test, bedside evaluation of oral intake will also be undertaken. This entire process is completed by a speech-language therapist. Cough reflex testing involves the presentation of aerosoled citric acid solutions (0.8 and 1.2 mol/L) diluted in 0.9% sodium chloride via a facemask and nebuliser. Each presentation last for 15 seconds. Initially, a placebo (0.9% sodium chloride), is presented in order to demonstrate the test to the patient. Then, the lowest dose of citric acid is presented to the patient for 15 sec with the instructions "cough if you feel the need to cough". Presence/absence and strength of cough is documented. This process is repeated 3 times, with 30 sec between presentations to prevent tachyphylaxis. The patient is then asked to try and suppress the cough. The ability to suppress constitutes a failed response. In case of such a response, the test is repeated at 1.2 mol/L. A speech-language therapist trained in cough reflex testing administers the test. The results of cough reflex testing rigidly dictate subsequent swallowing managment. Patients who present at least 2 out of 3 present, strong reflexive coughs and who cannot suppress at 0.8 and/or 1.2 mol/L proceed to oral trials at bedside. Patients who present with 2/3 weak or absent reflexive coughs, or who are able to suppress their cough at 1.2 mol/L remain nil by mouth, and are referred for an instrumental assessment of swallowing (videofluoroscopy). A subgroup of patients (n = 102) will also undergo cough reflex threshold testing. The methods for this are identical to those described above, with the addition of two further concentrations of citric acid (0.6 and 1.0 mol/L). Citric acid will be presented from lowest dose to highest. The lowest concentration that elicits at least 2/3 strong reflexive coughs will be considered the patient's cough threshold, and the test will stop. A sample of oral mucosa will also be obtained in this subgroup using oral swabs. A speech-language therapist trained in these techniques will perform the test and obtain the samples. Outcome measures will be taken upon discharge from acute stroke unit (approx 7-10 days) and at 3 months. The primary outcomes of interest are presence/absence of pneumonia, S. mitis and S. pneumonia. The relationship between pneumonia, oral bacteria, and cough reflex threshold will also be quantified.