Efficacy of Six Tasks to Clear Laryngeal Mucus Aggregation

Clinicians commonly teach patients alternative clearing behaviors to reduce coughing and hard throat clearing with the assumption that these behaviors clear mucus from the vocal folds. Yet there is limited evidence of the effectiveness of these alternative behaviors at clearing mucus. This study's purpose was to evaluate the efficacy of reducing laryngeal mucus aggregation using alternative approaches in comparison with hard coughing and hard throat clearing in people with and without voice disorders.

Mucus aggregation of 46 participants, 22 with and 24 without voice disorders, was evaluated from stroboscopy recordings taken before and after each of six clearing behaviors: hard coughing, hard throat clearing, silent coughing, soft throat clearing, dry swallowing, and swallowing with a fluid bolus. Each participant performed each clearing behavior twice. Two trained raters evaluated mucus aggregation for type, thickness, and pooling.

Of the six clearing behaviors studied, only hard throat clearing changed vocal fold mucus aggregation. The features of mucus aggregation that were changed by hard throat clearing were the severity of mucus thickness and the presence of type 3 mucus.

Despite the widespread clinical use of alternative clearing behaviors, the results of this study indicate that hard throat clearing is the only clearing behavior to have a significant impact on removing mucus aggregation from the vocal folds. This finding should be further investigated in a larger scale study. If the results of this study are replicated, clinicians should consider changing their use and description of alternative clearing behaviors in clinical practice.