CSAS assessment occurs in a sleep disorders center, through a full-night polysomnography (PSG). CSAS assessment occurs in a sleep disorders center, through a full-night polysomnography (PSG). A complete assessment involves confirming that the apnea-hypopneas are central in nature, with no inspiratory effort occurring during the event.¹ (See Figure 3b.)

Diagnostic criteria for CSAS include an Apnea-Hypopnea Index (AHI) of five or more (> 5) central apneas-hypopneas per hour of sleep; reported excessive daytime sleepiness; frequent nocturnal awakenings; or waking up feeling short of breath. ²

A diagnosis of Cheyne-Stokes respiration is based on at least 10 central apneas and hypopneas per hour of sleep, and a waxing and waning respiratory pattern. ³

Figure 3b: Polysomnographic recording of two episodes of central sleep apnea. Note the lack of respiratory effort during each CSA event.

Once a diagnosis of CSAS is established by determining the number of events and the resulting degree of sleep disturbance and O2 desaturation, the patient’s response to potential treatments is assessed.

References

1. Wellman A, and D White, “Central Sleep Apnea and Periodic Breathing,” in Kryger M, Roth T, Dement W (ed.), Principles and Practice of Sleep Medicine (5th Edition), St. Louis: Elsevier Saunders, 2011, pages 1140-1152.
2. Wellman A, and D White, “Central Sleep Apnea and Periodic Breathing,” in Kryger M, Roth T, Dement W (ed.), Principles and Practice of Sleep Medicine (5th Edition), St. Louis: Elsevier Saunders, 2011, pages 1140-1152.
3. Wellman A, and D White, “Central Sleep Apnea and Periodic Breathing,” in Kryger M, Roth T, Dement W (ed.), Principles and Practice of Sleep Medicine (5th Edition), St. Louis: Elsevier Saunders, 2011, pages 1140-1152.