Air Stacking or “Frog Breathing”
Both inspiratory and, indirectly, expiratory muscle function can be assisted by “air stacking”, technically known as “glossopharyngeal breathing” (GPB). For individuals with weak inspiratory muscles and no ability to breathe on their own, GPB can provide normal lung ventilation and perfect safety throughout the day without using a ventilator or in the event of sudden ventilator failure day or night.
The technique involves the use of the glottis (throat) to add to an inspiratory effort by projecting (gulping) boluses of air into the lungs. The glottis closes with each “gulp”. One breath usually consists of 6 to 9 gulps of 40 to 200 ml each. During the training period the efficiency of GPB can be monitored by spirometrically measuring the milliliters of air per gulp, gulps per breath, and breaths per minute. A training manual and numerous videos are available.
GPB is rarely useful in the presence of an indwelling tracheostomy tube. It cannot be used when the tube is uncapped as it is during tracheostomy IPPV, and even when capped, the gulped air tends to leak around the outer walls of the tube and out the stoma as airway volumes and pressures increase during the GPB air stacking process. The safety and versatility afforded by GPB are key reasons to eliminate tracheostomy in favor of noninvasive aids.