Usefulness of a handheld nebulizer in cough test to screen for silent aspiration

Cough test to screen for silent aspiration (SA) was reported, and the effectiveness was excellent. However, the device was rather large so that the portability was poor. So, the purpose of this study is to investigate the usefulness of a handheld nebulizer for the test and verify the reproducibility of the method. The subjects were 160 patients who were suspected of having dysphagia and underwent videofluorography (VF) or videoendoscopy (VE). They inhaled 1.0 % citric acid-physiologic saline orally for 1 min using a handheld nebulizer, and the examiner observed the number of coughs: more than five coughs was considered as negative (normal), while less than four coughs was regarded as positive. Among the subjects, 70 patients administered the cough test and VF or VE twice or more at some intervals. The k coefficient was calculated in reproducibility. Using the results of the VF or VE examination as the standards, for SA detection, the sensitivity was 0.86, specificity was 0.71, positive predictive value was 0.53, and negative predictive value was 0.93. The k coefficient was 0.79. In conclusion, the handheld nebulizer was useful in the cough test to screen for SA. Furthermore, satisfactory reproducibility was shown.