ASV was developed for treatment of Cheyne-Stokes Breathing (CSB), a pattern of slow waxing and waning of respiratory effort and airflow, but may be used for any patient manifesting central respiratory events accompanied by low CO2 levels (hypocapnia). Such patients generally manifest high ventilatory drive and ventilatory control instability. The pressure support (the I-E difference) of such devices treats such patients by providing higher pressure support (larger I-E differences) when flow and tidal volume are decreased (e.g., during a central respiratory event), and lower pressure support (a smaller I-E difference) when flow and tidal volume are increased. The result is stabilization of the patient’s ventilation by eliminating central apnea effected by excessive ventilation and low CO2 levels in blood.
ASV has been shown to be useful in treating Central Sleep Apnea with Cheyne Stokes Breathing. Primary Central Sleep Apnea, PAP-emergent Central Sleep Apnea, and narcotic-induced Central Sleep Apnea.