Changes

In addition to scoring OAs, CAs, Hs, snoring, and FLs, the '''Philips Respironics System One machines''' also score ''respiratory effort related arousals (RERAs)'' and '''periodic breathing''' (PB) in the events table with flags on the Flow Rate curve.

On an overnight PSG, a ''RERA'' is scored when there is evidence of increasing respiratory effort that ends with an EEG arousal. Not all labs score RERAs, by the way. The line between RERA and an AASM Rule 4B "hypopnea with arousal" is a bit arbitrary: RERAs don't have have last 10 seconds, but 4B hypopneas do; RERAs do not require a 50% reduction in airflow, but 4B hypopneas do. And a RERA requires an EEG arousal, whereas a Rule 4B hypopnea requires either an arousal OR an O2 desat of 3%. Finally a RERA may nor may not have an O2 desat. When a lab chooses to score RERAs, the lab will usually compute both an AHI and an RDI: