Airway protection during breath-holding.

Little is known about laryngeal function during breath-holding. The completeness of laryngeal closure during breath-holding is clinically relevant during the supraglottic swallow. To investigate this phenomenon, vocal cord position was studied prospectively in 10 adults during breath-holding using nasolaryngoscopy with video recording. The position of the vocal cords was not consistent during breath-holding. Some subjects closed the glottis, while others had variable amounts of glottic opening. Straining and vocalizing at the onset of breath-holding produced both glottic and supraglottic closure, increasing the number of levels of laryngeal closure during breath-holding. Nasolaryngoscopy can be used clinically to document the airway protection, the effects of various protective maneuvers, and any resulting aspiration during breath-holding and during the supraglottic swallow.