Glossopharyngeal breathing can allow a lung expansion greater than inspiratory capacity in muscular dystrophy

Glossopharyngeal breathing(GPB), also called “frog breathing”, is a positive pressure breathing technique that uses muscles of the mouth and pharynx to propel small volumes of air (“gulps”) into the lungs. It consists of three phases: 1) mouth opening so that air enters the oral and pharyngeal cavities; 2) mouth closure with tongue and pharyngeal musclespropelling a gulp of air through the open glottis, that raises; 3) glottisclosure to ensure the air trappedinto the lungs [1, 2]. These three phases are repeated several times until a comfortable lung expansion is reached. GPB is known to be able to increase lung volumesabove physiological total lung capacity (TLC) therefore increasing vital capacity [2–5]. This is the consequence of an increase in lung volume, but also of intrapulmonary gas compression. The physiological factors limiting TLC are the effect of the inspiratory muscles that rapidly decreases and the elastic expiratory (inward) recoil of lungs and chest wall that increase. By contrast, TLC during GPB seems to be limited by sensation rather than by respiratory muscles and/or the mechanics of the respiratory system [3]. GPB is largely used by divers because it increases the amount of oxygen/carbon dioxide stored in the body therefore prolonging their breath-hold duration [3, 6, 7]. GPB can also be used as lung inflation therapy to assist the ventilatory pump when it becomes weak or impaired, as in the case of cervical spinal cord injury and/or neuromuscular diseases[8]. Footnotes This manuscript has recently been accepted for publication in the European Respiratory Journal . It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJ online. Please open or download the PDF to view this article. Conflictof interest: Dr. LoMauro has nothingto disclose. Conflictof interest: Dr. Banfi has nothingto disclose. Conflictof interest: Dr. Aliverti has nothingto disclose. Conflictof interest: Dr. D'Angelo has nothingto disclose.