(07-11-2015, 02:47 PM)tedburnsIII Wrote: Is it possible to have a CSR-type pattern of breathing where the machines will not report it as some kind of apneaic event (ap, hyp, CA)?
Question posed in part because some machines, including mine, do not have access to SleepyHead.
The definition of an apnea, whether in CSR or not, is the same: at least 90% reduction in respiration for at least 10 seconds. The apneas in CSR will be counted in the AHI and also in the RDI (Respiration Disturbance Index) if the machine also reports RERA and RDI.
But if a period of no breathing lasts 9.5 seconds it might not be reported. And if what looks like CSR repeats every 29 seconds (instead of 30 to 120 seconds) it might not be flagged as CSR, but the individual apneas (if lasting at least 10 seconds) will still be reported.
The RDI is equal to the AHI (average per hour of the sum of apneas plus hypopneas) plus the average per hour of RERA events. RERA is a Respiratory Effort Related Arousal, which is an arousal caused by needing to exert too much effort in breathing, usually caused by Flow Limitation.
Flow Limitation is caused by a partial restriction of the airway which limits the Flow rate while we are inhaling, which can make inhalation uncomfortably hard, which may lead to an arousal.
The fully data-capable PRS1 (Philips Respironics System One) machines have been (estimating and) reporting RERA for several years, but most "fully data-capable" ResMed machines do not attemp to (estimate and) report RERA. The A10 AutoSet For Her was the first ResMed model to report RERA. Recently, in some regions, users have reported their standard (meaning not the For Her model) A10 AutoSet also reports RERA. Haven't heard yet whether any of the new AirCurve 10 bilevel machines have started reporting RERA.
RERA events are arousals which disturb sleep, but because the reduction in respiration was less than 50% (or because some other requirement for being classified as hypopnea was missing) these will not be counted as hypopneas and therefore will not be counted in the AHI. (By definition, an event cannot be counted both as a RERA and as an hypopnea.)
So, conceivably, a person who has lots of RERA but few apneas and hypopneas may have a great AHI but may be unable to sleep well and may feel always fatigued and mentally foggy, etc.
Higher pressure or bilevel PAP therapy can help prevent Flow Limitation and RERA. If the person is using fixed-pressure CPAP therapy, it may help to turn on EPR (if available) and increase the Pressure setting by a corresponding amount - for example increasing the Pressure setting by 1 or 2 if now using an EPR setting of 2 cmH2O but the Pressure setting had been based on a lab titration which did not use EPR during the titration. (This would maintain the pressure used during exhalation closer to what had been determined to be needed during the lab titration.)