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Anyone with low AHI but symptomatic?
(09-20-2013, 01:05 PM)Tim M Wrote: Has anyone out there had mild Apnea but terrible sleep? ... I have 6.6 AHI but wake with anxiety and feel as though I have not been breathing. The last 3 hrs. of sleep are very agitated, waking with flashes of panic. I feel hungover, wrenched neck, headache and tired.

Hi everyone,

Basic CPAP titration principles:

The EPAP exhalation pressure needs to be high enough to prevent obstructive apneas and hypopneas, which are most likely to start at the end of exhalation / very beginning of inhalation. (And we usually are more likely to need higher pressure whenever we sleep flat on our back, so if we want to minimize our pressure needs then it is usually good to ensure we never sleep flat on our back.)

It usually helps for the IPAP inhalation pressure to be higher than EPAP, both to help us to breathe in more easily (which makes therapy more comfortable and reduces anxiety) and to help prevent something called RERAs (Respiratory Effort-Related Arousals) which are not apneas or hypopneas yet can prevent us from achieving deep restorative sleep.

RERA or UARS events, a major (but often overlooked) problem for some:

Some people have lots of sleep-disrupting events called RERA (Respiratory Effort-Related Arousal, also called UARS for Upper Airway Resistance Syndrome) events which do not show up in our AHI numbers.

The usual treatment to eliminate RERA events is bi-level PAP. Increasing the difference between the inhale pressure (IPAP) and the exhale pressure (EPAP) makes breathing easier and eliminates RERAs. (The amount that IPAP is higher than EPAP is called Pressure Support on some bi-level machines. The amount that EPAP is lower than IPAP is called EPR or Flex on some standard PAP machines.)

Here is a link to a very important article which discusses RERA (also called UARS) events:

If we are using EPR or Pressure Support or another form of bi-level therapy, a higher setting for EPR or Flex or Pressure Support may reduce RERA events, but (for a few people) a higher setting may increase central apnea events.

If our main problem is RERA events (which the S9 machines do not report) and if we have already been using EPR or Flex set to its maximum value of 3, we may benefit from a bi-level Auto machine which can deliver a larger difference between inhale pressure versus exhale pressure and, because it is an Auto machine, it can minimize our average therapy pressure by minimizing our EPAP pressure. Examples of this type of machine would be the PRS1 BiPAP Auto or the ResMed S9 VPAP Auto. (Personally, I think the PRS1 machine is more advanced than the competing ResMed machine, because I think the PRS1 Auto BiPAP can be set up to slowly automatically adjust its Pressure Support as needed to reduce RERAs, but on the ResMed VPAP Auto the Pressure Support can only be adjusted manually.)

If bi-level treatment causes our Central Apnea Index (CAI) to get larger than 5.0, then an ASV machine may be prescribed which would be able to treat/prevent both our obstructive and central events. However, some insurance companies will not cover an ASV machine unless the CAI is at least 15 ("moderate"), which would mean we could be faced with the prospect of paying for the ASV machine on our own, if we want to pursue ASV treatment. New ASV machines are nearly US$ 2,000 from Supplier #2 on our Supplier List, and used machines are somewhat less. Examples of this type of machine would be the PRS1 BiPAP autoSV Advanced or the ResMed S9 VPAP Adapt.

If our main problem is central apnea events and if we have been using EPR or Flex or Pressure Support of 3 or higher, we may benefit from turning EPR/Flex/PS down or off, because (for a few people) turning it down or off can reduce or largely eliminate central apnea events and make sleep more restful.

So, what to do? Turn EPR/Flex/Pressure Support very slowly up (increasing like 1 cm H2O per week or two)? Or turn it very slowly down and then off? Either one might help.

(09-20-2013, 01:05 PM)Tim M Wrote: But some doctors say my AHI shows Apnea is not my problem and they point to things like depression and better sleep hygiene. I have a profound problem I think these doctors are really out of the loop when I describe these symptoms and they dismiss Apnea because of my AHI. Now I am looking at MMA surgery. Can anyone here relate?

I think most doctors primarily pay attention to our AHI numbers (not our machine's detailed data). RERA events are not included in our AHI number, and I think many doctors are unaware of the problems caused in some patients by RERA events and do not understand that increasing the difference between IPAP and EPAP (by increasing the IPAP) might be all that is needed to obtain a great improvement.

Take care,
--- Vaughn
Membership in the Advisory Member group should not be understood as in any way implying medical expertise or qualification for advising Sleep Apnea patients concerning their treatment. The Advisory Member group provides advice and suggestions to Apnea Board administrators and staff on matters concerning Apnea Board operation and administrative policies - not on matters concerning treatment for Sleep Apnea. I think it is now too late to change the name of the group but I think Voting Member group would perhaps have been a more descriptive name for the group.
(09-22-2013, 09:46 AM)archangle Wrote: You may have to take charge of your own CPAP therapy.

What exact model of BiPAP machine do you have?

What does it say on the top of the blower unit?

Is it a Philips Respironics unit, or just a Respironics unit?

Which one of these does it look like?

What software do you have?

Before you risk being butchered with further surgery, you need to get a really good look at your breathing while using CPAP.

Even an AHI of 6.6 can really screw you up.
2012-2013 Phillips Respironics System One BiPAP Auto Bi-Flex.  I don't have any software.
(09-22-2013, 04:36 PM)Kritiker Wrote: There are many things that can disrupt sleep sufficiently to be debilitating and they may coexist with sleep apnea.

If you haven't already done so, you might want to consider:
  • having your medical history reviewed by a sleep specialist
    • Respirologist (Pulmonologist) for possible respiratory problems, over and above your OSA
    • Neurologist for possible neurological problems, e.g., PLMD/PLMS (periodic limb movements during sleep)
    If you have already consulted sleep specialists, you might want to consult different ones, to get a second opinion.
  • getting a full-blown overnight sleep test (i.e, Level 1 Nocturnal Polysomnography) in a reputable sleep lab to monitor
    • brain waves (EEG)
    • heart rhythm (EKG)
    • breathing patterns
    • oxygen levels
    • limb movements
Level 3 Polysomnography, i.e., essentially a sleep apnea trial with an APAP machine, may provide only an incomplete picture of your situation.

Thank you Kritiker. Unfortunately, I have done all of the above more than once. Since 1991 I've had probably 6-8 sleep studies and have seen 40-60 doctors of varying specialties. Surgeons have mostly been willing to do surgery. Sleep specialists screen me for the above and end up telling me about sleep hygiene. One neurologist said it was depression but when the meds didn't help, ran out of options. A couple doctors said lose weight and sleep on side but I have been at ideal body weight and still had absolutely no difference.

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