Mixed Apnea Metrics in Obstructive Sleep Apnea Predict Treatment-Emergent Central Sleep Apnea

Treatment-emergent central sleep apnea (TE-CSA) describes the occurrence of central respirator)' events after the initiation of continuous positive airway pressure (CPAP) therapy in patients with predominant obstructive sleep apnea (OSA). "CPAP-emergent" TE-(ISA (i.e.. central sleep apnea emerging during CPAP initiation with complete resolution after 8-12 weeks of CPAP therapy) represents the predominant TE-CSA subgroup and is a transient phenomenon that does not require early therapy escalation. Aside from many other factors, OSA is influenced by an instability of the ventilatory drive, which can be quantified by the loop gain (1.G). Higher LG reflects increased sensitivity and reactivity of the ventilatory control system, resulting in overshooting and undershooting of the ventilation. We postulated that a high LG is a relevant pathophysiological factor for the development of CPAP-emergent TH-CSA. Sands and colleagues proposed a method to derive the LG from routine polysomnography (PSG) in patients with periodic breathing (PB) based on the duty ratio (OR) without the need for specialized signal analysis algorithms/.