The accuracy of the modified Evan's blue dye test in detecting aspiration in tracheostomised patients

To evaluate the sensitivity and specificity of the modified Evans blue dye test compared to the fibre-optic endoscopic evaluation of swallowing to detect aspiration in tracheostomised patients.

This observational accuracy study included 17 patients hospitalised for respiratory complications, subjected to prolonged intubation, and for this reason, tracheostomised.

Mean patient age was 60.2 ± 21.0 years. Aspiration was identified in 10 patients when assessed by fibre-optic endoscopic evaluation of swallowing; of these, 1 had aspiration when evaluated by modified Evans blue dye test. The dye test had a sensitivity of 10.0 per cent and specificity of 100.0 per cent for detecting aspiration. Fibre-optic endoscopic evaluation of swallowing revealed no statistically significant associations between aspiration presence and: speech and language therapy duration, intubation time, or tracheostomy plus mechanical ventilation duration.

The modified Evans blue dye test is simple and inexpensive, and does not require prior knowledge in endoscopy; it may be used as an initial screening test in all tracheostomised patients for evaluating aspiration. However, fibre-optic endoscopic evaluation of swallowing should be used for a more comprehensive diagnosis of tracheostomy patients, especially for those at high risk for aspiration.