A new method for enhanced expectoration of sputum by vibratory stimulation of the cervical trachea

Expectoration of sputum can be difficult for patients with respiratory conditions such as chronic obstructive pulmonary disease, chronic bronchitis, or bronchiectasis because of the effects of decreased pulmonary function, respiratory muscle fatigue, altered sputum properties, and impaired ciliary function. We developed a new method for the vibratory stimulation of the cervical trachea and this study aimed to compare it with the Acapella (a current oscillation device) method.

Patients with chronic productive cough and difficulty with expectoration were recruited for the study. The tracheal vibration and Acapella methods were applied for 4 weeks each, according to a crossover design with an intervening 4-week washout period. To perform the tracheal vibration method, an electronic artificial larynx (Yourtone®) was applied to the cervical trachea for up to 5minutes. Patient preference for the two devices was determined from the performance scores recorded for each device and by using a visual analogue scale.

Twelve patients were recruited in the study. According to the performance scores assigned by the subjects, the tracheal vibration method was effective in 9 patients, while the Acapella method was effective in 10 patients. Both methods were effective in 8 patients, among whom the tracheal vibration method was more effective in 5 patients. Both methods were found to be ineffective in 1 patient.

The tracheal vibration method may be effective at removing central airway sputum and does not require repeated forced expiratory effort, which can otherwise cause exhaustion in patients with decreased lung function. Further investigation is required to confirm its use as a new oscillation technique.