Screening for silent aspiration in hyperacute stroke: A feasibility study of clinical swallowing examination and cough reflex testing.

BACKGROUND: Silent aspiration (SA) is common post-stroke and associated with increased risk of pneumonia, length of stay and healthcare costs. Clinical swallow examinations (CSEs) are unreliable measures of SA. There is no consensus on the clinical components that best detect SA. Cough reflex testing (CRT) is an alternative/adjunct whose SA detection accuracy also lacks consensus.

AIMS: To investigate the feasibility of CSE versus CRT against gold standard flexible endoscopic evaluation of swallowing (FEES) for SA identification and to estimate its prevalence in a hyperacute stroke setting.

METHODS & PROCEDURES: A single-arm preliminary, prospective, feasibility study of patients less than 72 h post-stroke, over a 31-day period on a hyperacute stroke unit: the Royal Victoria Infirmary, Newcastle-upon-Tyne, UK. Ethical approval for the study was obtained. The study tested the feasibility and acceptability of introducing CRT and developing a standardized CSE. Consent/assent was obtained for all participants. Patients unfit for study were excluded.

OUTCOMES & RESULTS: A total of 62% of patients less than 72 h post-stroke (n = 61) were eligible. A total of 75% of those approached (n = 30) consented. A total of 23 patients completed all tests. The principal barrier was anxiety regarding FEES. Mean test time for CRT = 6 min; CSE = 8 min; FEES = 17 min. Patients rated CRT and FEES on average as moderately uncomfortable. A total of 30% (n = 7) of participants who received FEES presented with SA.

CONCLUSIONS & IMPLICATIONS: CRT, CSE and FEES are feasible in 58% of hyperacute stroke patients in this setting. FEES anxiety is the main recruitment barrier and is not always well tolerated. Results support further work to establish optimum methods and differential sensitivity/specificity of CRT and CSE in hyperacute stroke for SA identification.

WHAT THIS PAPER ADDS: What is already known on this subject SA significantly increases the risk of pneumonia in the early days post-stroke. CSEs are unreliable for identification of SA risk in this population. CRT is gaining popularity as a potential tool to identify stroke patients at risk of SA, though there are questions regarding the efficacy of the clinical protocol currently being used in the UK. What this study adds to existing knowledge This study demonstrates that it is practical and feasible to carry out a larger scale study in this setting to compare CSE and CRT including a consideration of an approach combining both methods for clinical identification of SA versus FEES. Preliminary findings suggest that CSE may have higher levels of sensitivity than CSE for SA identification. What are the potential or actual clinical implications of this work? The results of this study suggest that further work is needed to establish the optimum methods and differential sensitivity/specificity of clinical tools for SA detection in hyperacute stroke.