Inhalation vs Apnea

I'm new to the wonderful world of cpap, having used the machine for the first time last night. What I found is that, although the machine blows air into my nose and mouth, the one thing it doesn't do is cause me to inhale, a vital component of breathing. Inhalation, as I understand that, (especially during sleep) is controlled by the autonomic nervous system, and is triggered by a signal of some kind sent to the diaphragm/lungs that causes the lungs to inflate. The air that's being pumped into my nose/mouth by the cpap machine is fine, but it's useless if the reason I stop breathing isn't an obstruction in my airway, but rather my body's failure to send that vital signal that triggers inhalation. What am I missing?

You are missing the difference between an obstructive event and a central event.
It would be helpful if you would post your equipment list by following the link in my signature block below.

It would also be helpful to you if you could do the following:
1. Get a copy of your sleep study / titrations study so that you could see the kinds of apneas you were having during the study. That would establish a baseline to see the improvement the CPAP therapy provides.
2. Get a copy of your prescription for your own records.
3. Get the appropriate software for your machine so that you can see the efficacy of your treatment. Hopefully, you got a machine that does record efficacy data and not a "brick" that only records hours of use. We won't be able to tell that until your equipment profile is filled in.

Martskers,

CPAPs and APAPs are NOT ventilators. They will NOT try to force you to inhale. When set correctly your CPAP uses the positive air pressure to splint the airway open and makes it much harder (but not impossible) for the upper airway to collapse and become obstructed. Because it is much harder, but not impossible, for the airway to collapse, the number of obstructive events is reduced to the normal range.

If the problem on the diagnostic sleep test is indicated as central sleep apnea instead of obstructive sleep apnea, then a plain CPAP/APAP might not be very effective, but many insurance companies will insist on trialing the patient on a CPAP/APAP before moving them to a more expensive machine that can do a better job of treating the central sleep apnea. But central sleep apnea is much rarer than plain old obstructive sleep apnea. Hence JDS74's suggestions that you obtain copies of your sleep studies. You need to know what the diagnosis actually is and how/why CPAP/APAP has been chosen as the starting point for treatment.

If your machine is scoring a lot of CAs---the CAI > 5 and you have very large numbers of CAs scored when you know (for sure) that you were sound asleep, then something is not working as expected. And it's time to report the problem with CAs to your sleep doc so that s/he and you can work together on figuring out what the next step in treating your problem is.

Martskers wrote:I'm new to the wonderful world of cpap, having used the machine for the first time last night. What I found is that, although the machine blows air into my nose and mouth, the one thing it doesn't do is cause me to inhale, a vital component of breathing. Inhalation, as I understand that, (especially during sleep) is controlled by the autonomic nervous system, and is triggered by a signal of some kind sent to the diaphragm/lungs that causes the lungs to inflate. The air that's being pumped into my nose/mouth by the cpap machine is fine, but it's useless if the reason I stop breathing isn't an obstruction in my airway, but rather my body's failure to send that vital signal that triggers inhalation. What am I missing?

Please fill in the equipment on your profile and we can help you better. There's a link in my signature line.

Apena due to not trying to breathe is called "central apnea." When you had a sleep test, they should have detected it if you have central apnea.

Some people develop central apnea while using CPAP. If you had a proper "titration" to determine your correct pressure, they should have detected this. If you have a proper CPAP machine, it will detect central apnea and record the data. Some machines do this and some don't so we need to know what machine you have.

Central apnea may require different treatment than "normal" obstructive apnea.

I've updated my profile. I've also looked at the report of my "titration study," if that's the word for it (the second of the two studies, performed with a cpap in place). Please tell me what info you need from that study to further respond to my inquiry. Thanks.

On your titration sleep study was there a mention as to the number of "centrals"? If so, does it give an hourly average/index for the number centrals?
What was your official diagnosis?

The important numbers are:

1. Obstructive events per hour
2. Hypopneas per hour
3. Central events per hour
4. Pressure at which obstructive events were resolved. This is the minimum pressure at which no more obstructive event occurred.

What you described in your OP was a central event, i.e., your airway was open but you weren't breathing.
If you were awake when this was happening, its the equivalent of just holding your breath. The pressure from your machine is unlikely to be enough to act as a ventilator under those circumstances. The pressure from my machine can and does do that under those circumstances. You have an auto CPAP which doesn't.

Martskers wrote:I've updated my profile. I've also looked at the report of my "titration study," if that's the word for it (the second of the two studies, performed with a cpap in place). Please tell me what info you need from that study to further respond to my inquiry. Thanks.

See if there's a table like this:

There is no such table in my report, but there is the following:

"The patient's apnea/hypopnea (AHI) index was 0.3 events per hour of sleep. The REM AHI was 0.0. Of these events, 0 were apneas, including 0 obstructive apneas, 0 central apneas and 0 mixed apneas. There were 1 hypopneas. The apnea/hypopnea arousal index was 0.3 events per hour of sleep. The respiratory disturbance index (RDI) was 1.8. The longest respiratory event lasted 22.0 seconds. Cheyne Stokes was not observed."

There are other findings as well, including:

"Obstructive sleep apnea syndrome that is severe, associated with oxygen desaturations and corrected with 10 cm in REM sleep while on sides. Probably cor pulmonale, due to severe and prolonged hypoxia while sleeping at night"

Interestingly, while the recommendations section of the titration report recommends a nasal mask with added oxygen, when they fitted me for the device (and sent me home with it), it was the one listed in my profile; not a nasal device and no oxygen.

Oh, and while I'm at it, I have two other questions:

I can't tell if the humidifier is actually working. I know it's supposed to be heated (while the tubing is not), but the only source of heat seems to be hot air being blown over the water in the reservoir. And, I can't tell that the water level is diminishing, at all. It doesn't seem to be, and if so, almost imperceptibly. Finally the only issue I have with the mask is the resistance to exhalation. Sometimes, I feel like I have to exhale through my mouth to overcome that resistance.

Martskers wrote:I've updated my profile. I've also looked at the report of my "titration study," if that's the word for it (the second of the two studies, performed with a cpap in place). Please tell me what info you need from that study to further respond to my inquiry. Thanks.

Your PRS1 Auto is a good machine. It will attempt to detect central apneas. You can get the free SleepyHead program and download your data to your computer to see if you're having centrals.

BTW, central apnea is fairly rare. Most of us apneacs have obstructive apnea, not central.

Martskers:

Sounds as if you are reading from the titration report and that all the numbers indicate the sleep lab found that 10 cm H2O resolved almost everything. Of special note is the 0 values for central and mixed apneas.

What that means is that the level of pressure you have doesn't cause pressure sensitive central apneas. That's really good news.

The humidifier in a PR System One heats from a plate under the water chamber. The system measures the humidity of the inout air and adjust accordingly. Check the setup screen to see if the humidifier is turned on. That could be the reason that little water is being used. Humidity is a comfort issue so the value set is related to how you feel and not some medical issue. Except if one uses the Oracle 2 mask that I use. Then high humidity is mandatory - but that doesn't apply to you.

The feeling of fighting the pressure is a common one. Over time you will become used to the pressure and wonder if the machine is blowing at all.

For now, I suggest that you experiment with the ramp function. Try setting ramp start to 4 cm H2O and ramp time to 20 minutes. 20 minutes is a pretty normal amount of time to go to sleep and the initial low pressure will help with that feeling. After things are doing well, I recommend turning ramp off so that effective therapy starts immediately - but that is for later.

If you are comfortable with the Simplus mask, then that is fine. You can breathe through your nose (highly recommended) or through your mouth, whatever is comfortable. If you mouth breathe very much, be sure the humidifier is working and you are not waking up with a dry mouth.