Comparison of cough reflex test against instrumental assessment of aspiration

• Published in: Physiology & behavior 2013-06, Vol.118, p.25-31
• Main Authors: Miles, Anna, Moore, Sara, McFarlane, Mary, Lee, Fiona, Allen, Jacqueline, Huckabee, Maggie-Lee
• Format: Article
• Language: English
• Subjects: Adult; Aged; Aged, 80 and over; atomization; Behavioral psychophysiology; Biological and medical sciences; Citric Acid; Cohort Studies; cough; Cough - chemically induced; Cough - physiopathology; Cough reflex testing; Data Interpretation, Statistical; deglutition; Deglutition - physiology; Dysphagia; Endoscopy; Esophagus; Female; Fluoroscopy; Fundamental and applied biological sciences. Psychology; Gastroenterology. Liver. Pancreas. Abdomen; Humans; Likelihood Functions; Male; Medical sciences; Middle Aged; mortality; Odds Ratio; Optical Fibers; Other diseases. Semiology; patients; Pneumology; pneumonia; Psychiatry; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Reflex - physiology; Reproducibility of Results; researchers; Respiratory system : syndromes and miscellaneous diseases; Silent aspiration; Validity; Young Adult
• ISSN: 0031-9384; 1873-507X
• DOI: 10.1016/j.physbeh.2013.05.004

Abstract Background Silent aspiration is associated with pneumonia and mortality, and is poorly identified by traditional clinical swallowing evaluation (CSE). The aim of this study was to validate cough reflex testing (CRT) for identification of silent aspiration against aspiration confirmed by instrumental assessment. Methods Cough reflex threshold testing was completed on all patients using inhaled, nebulised citric acid. Within an hour, 80 patients underwent videofluoroscopic study of swallowing (VFSS) and 101 patients underwent fibreoptic endoscopic evaluation of swallowing (FEES). All tests were recorded and analysed by two researchers blinded to the result of the alternate test. Results Significant associations between CRT result and cough response to aspiration on VFSS (X2 (2) = 11.046, p = .003) and FEES (X2 (2) = 34.079, p < .001) were identified. Sensitivity and specificity were optimised at 0.6 mol/L in patients undergoing VFSS (71%, 60% respectively) and at 0.4 mol/L in patients undergoing FEES (69%, 71% respectively). A concentration of 0.8 mol/L had the highest odds ratio (OR) for detecting silent aspiration (8 based on VFSS; 7 based on FEES). Conclusion CRT results are significantly associated with aspiration response on instrumental assessment. Lower concentrations of citric acid provide a better predictive measure of silent aspiration.