Objective measurement of acoustic intensity of coughing for clearance of penetration and aspiration on video-fluoroscopy

Purpose: This preliminary, exploratory study evaluated the acoustic intensity of effective and ineffective clearance of penetrated and aspirated material from the laryngeal vestibule in patients with dysphagia.
Method: A lapel microphone was attached anterior to participants’ tragus and recorded coughing in decibels during their videofluoroscopic swallowing studies (VFSS).
Result: Eighty-eight patients were recruited. Thirteen patients, with visible airway invasion and coughing were included in the final analysis. No coughs were effective at expelling aspirated material from the airway (n 1⁄4 10). Both effective (4/7) and ineffective (3/7) coughing to penetration were recorded. The mean acoustic intensity of effective coughing to penetration was –44.0 dBFS (decibel level relative to full scale) [SD 1⁄4 7.3, 95% CI 1⁄4 51.14, 36.86], and ineffective coughing to penetration was only marginally lower at –42.9 dBFS [SD 1⁄4 2.0, 95% CI 1⁄4 45.21, 40.59].
Conclusion: No coughs were effective at expelling aspirated material from the airway. Some coughs effectively expelled penetrated material from the airway. However, the relationship between acoustic intensity and cough effectiveness is unclear due to the limited number of observations. Given that perceptual evaluation of coughing is widely used in dysphagia clinical practice to determine cough effectiveness, this is an important area for future research.