Assessment of aspiration risk in acute ischaemic stroke - Evaluation of the simple swallowing provocation test

Abstract

Background: Aspiration is a common complication in acute stroke patients and is strongly associated with a poor outcome. Due to an insufficient sensitivity and specificity of clinical bedside tests, further refinements are needed to improve the accuracy of clinical aspiration screening in acute stroke. Objective: To assess the ability of the simple 2-step swallowing provocation test (SPT) to detect aspiration risk in acute stroke patients. Methods: 100 consecutive patients with first-ever stroke were examined by SPT and fiberoptic endoscopic evaluation of swallowing (FEES) within 72 hours of stroke onset. Using FEES as an objective instrumental technique to evaluate dysphagia, statistical measures representing the ability of SPT to detect aspiration risk were calculated. Results: The incidence of endoscopically proven aspiration risk was 81%. The 1st-step SPT had a sensitivity of 74.1% and a specificity of 100%. Although the 2nd-step SPT showed the same 100% specificity, sensitivity was significantly lower. False-negative results of SPT appeared predominantly in subjects exhibiting leakage of liquids to pyriform sinus without a pronounced delay in swallow onset. Conclusions: In acute stroke patients with an impairment of the pharyngeal phase of swallowing, 1 st-step SPT reliably detects aspiration risk. In patients with a sole or predominant impairment of the oral phase of swallowing and a relatively intact pharyngeal phase, SPT fails to detect aspiration risk sufficiently. In the latter group, FEES or additional clinical features more specifically indicating oral-phase pathology should be considered to accurately judge the patient's aspiration risk.