(11-14-2014 10:03 AM)suedanem Wrote: Her doctor said, last night at 5:30, that just going ahead and using an APAP could possibly make things worse because mom had both central and obstructive apnea. (Can someone make a comment on this possibility?)
Ask for copies of the full sleep reports (not a one-page summary), including data and event graphs, for both sleep studies (not just for the most recent).
The doctor is correct.
A few people have both obstructive apneas and central apneas when sleeping without CPAP therapy. This is called Mixed or Complex Sleep Apnea. When being treated with CPAP, although the continuous pressure is needed to prevent obstructive apneas, the CPAP therapy will sometimes cause the number of central apneas to increase, perhaps worsening the overall AHI.
Some people have only obstructive apneas when not being treated with CPAP, but when being treated with CPAP the continuous pressure causes central apneas. This is called CPAP-emergent central sleep apnea or Mixed or Complex Sleep Apnea. Although the CPAP therapy is needed to prevent obstructive apneas, CPAP therapy will sometimes cause the number of central apneas to increase, perhaps worsening the overall AHI.
So standard CPAP or APAP treatment may make things better or worse, but usually makes things much better, at least if the pressure is limited so it does not go too high.
Oxygen Therapy (supplemental O2), in addition to raising the amount of O2 in the blood (which is important), tends to decrease the number of Central Apneas. I think there is more than one cause for Central Apneas, but one cause can be too little CO2 (carbon dioxide) in the blood. Supplemental O2 tends to increase the O2 content of the blood, which, as the O2 is used and is turned into CO2, tends to increase the amount of CO2 in the blood, helping to avoid the type of central apnea which is caused by too little CO2. However, any time we are using supplemental O2, we should at least occasionally (monthly?) wear a recording Pulse Oximeter at night, to verify we are not getting too much O2, which can cause many very serious health problems, such as rendering prescription medications ineffective, and accelerating Coronary Artery Disease, and generally increasing oxidative stress on our whole system.
The gold standard for treatment of Obstructive Sleep Apnea is CPAP/APAP/BiPAP, and the gold standard for treatment of mixed or Complex Sleep Apnea is a CPAP bi-level machine having an ASV (Adaptive Servo Ventilator) therapy mode. Several members of the forum need and use ASV machines.
The presently-available ResMed ASV machine is named the S9 VPAP Adapt. The presently-available Philips Respironics ASV machine is named the System One BiPAP autoSV Advanced.
The ResMed VPAP Adapt and the PRS1 BiPAP autoSV Advanced are similar to the AutoSet, which can automatically slowly raise the EPAP (the pressure during exhalation) to prevent obstructive apneas. (My own ASV machine is a 2012 model of the S9 VPAP Adapt which cannot automatically adjust EPAP, but the more recent models can.) The EPAP pressure is not raised by the AutoSet during an apnea, but is raised a little after each apnea or hypopnea ends, and is not raised if the apnea type is Central Apnea. The EPAP pressure is also slowly raised if the machine detects snoring or Flow Limitation.
The key additional feature of the ASV machines is that when a central or obstructive apnea or hypopnea begins, the ASV machine will act as a ventilator, by rhythmically increasing and decreasing the pressure, so that we naturally inhale and exhale, with the changing pressure doing for us some or all of the work of breathing. The amount by which the inhale pressure (IPAP) is higher than the exhale pressure (EPAP) in order to aid or cause inhalation, is called the amount of Pressure Support.
Typically, when the Pressure Support is raised up to 10 cm H2O, this is usually adequate to do for us all the work of breathing. For example, if the ASV machine has raised EPAP (the pressure the machine produces when it senses we are exhaling) up to 8 in order to prevent obstructive apneas from occurring, and if a central apnea suddenly starts, and if the machine raises Pressure Support to 10, then the machine would be cycling back and forth between an EPAP pressure of 8 (for exhalation) and an IPAP pressure of 18 (for inhalation). When we once again start breathing normally, the ASV machine reduces the amount of Pressure Support to whatever normal amount of Pressure Support is most comfortable for the user, which is usually between 1 and 5.
There are also non-ASV standard bi-level (VPAP or BiPAP) machines which can produce Pressure Support to help us inhale and exhale, but the amount of Pressure Support is fixed or very slowly self-adjusting, and these standard bi-level machines do not attempt to interrupt or treat central apneas.
Most ResMed CPAP and APAP models, such as the Elite and AutoSet and AutoSet For Her models, are able to use a limited form of bi-level which is named EPR for Expiration (meaning Exhalation) Pressure Relief. EPR is limited to amounts of 3 or lower, and EPR is the amount by which the EPAP pressure is lower than the IPAP pressure.