Journal of Clinical Trials
Open Access

Abstract

A Citric-Acid-Solution Swallowing Test is Useful as a Screening Test for Aspiration at Bedside and for the Early Detection of Swallowing Dysfunction

Kentaro Kobayashi, Mika Kobayashi and Masahiro Abo

We developed a citric-acid-solution swallowing test (CST) as a screening test for dysphagia with laryngopharyngeal sensory dysfunction. In this report, we evaluated the usefulness of CST in detecting aspiration and in evaluating swallowing dysfunction. The study subjects were 51 patients suspected of dysphagia. Videoendoscopy (VE), the modified water swallowing test (MWST) and the CST were performed on each patient. Swallowing dysfunction and aspiration were diagnosed by VE. On the basis of the diagnosis by VE, the sensitivity and specificity were each calculated for the MWST and CST, respectively. The sensitivity and specificity of CST for detection of aspiration was 94.4% and 69.7%. The sensitivity of MWST decreased to 57.9%, with a slight increase to 75 percent in specificity. The sensitivity and specificity of CST for evaluation of swallowing dysfunction was 96.3% and 95.8%. The sensitivity of MWST decreased to 66.7%, with no decrease in specificity. CST had a higher positive likelihood ratio and a lower negative likelihood ratio than MWST for both detection of aspiration and evaluation of swallowing dysfunction. The results suggest that the CST is more sensitive in the detection of dysphagia with laryngopharyngeal sensory dysfunction than the MWST, and that coughing could be induced by acid stimulation with citric acid. We conclude that the CST might be useful as a screening test for the detection of aspiration and swallowing dysfunction.