New sleep study new questions (fixed pressure vs. APAP)

[ColoradoMom]

Thank you for your input Crowtor! My son has not had a tilt test. His primary care doctor did an orthostatic vitals test which showed a supine heart rate of 60, the HR increased to 182 upon standing. My sons sleep doctor was actually the first doctor to suggest POTS which led to a cardiology referral. Unfortunatally the cardiologist has been somewhat dismissive. They did a 30 day holter which showed showed sinus tachycardia. They also did a cardio/ pulmonary exercise stress test. The cardiologist told me the results of the exercise test were normal. I told her my son is hypoxic and specifically asked about his pulmonary function, and she told me his pulmonary function was fine. I requested a copy of the test results and was blown away when I saw obstrucive lung disease listed under the findings. I sent the test results to his pulmonolgist which led to more pulmonary function tests and the asthma diagnosis. Anyway, I have concluded that my son's cardiologist is not the right doctor to treat his autonomic dysfunction, so I'm trying to get him into Mayo. 

My son had so many issues that have taken the doctors a long time to figure out. I am hoping that maybe his autonomic issues will improve as other issues are resolved. Your story gives me hope!

[Ron AKA]

I don't understand why increasing the CPAP pressure after his AHI numbers were good raised his mean oxygen saturation from 90 to 95, so I am hesitant to make changes myself since I really don't understand what is going on. 

I think the best course of action is to wait on APAP until discussing it with the doctor. I'm still considering increasing the pressure to a fixed 9 on my own. I have sleepy head, I'm at a different computer right now, but I'll post some charts this evening. Is there much risk in raising the pressure myself? I figure that if more centrals show up I can bump the pressure back down. In the grand scheme of things I guess a month isn't that long to wait, but I hate for his oxygen levels to remain low when there may be a remedy. Thank you once again for the many helpful replies!

When you increase pressure the air in the lungs will be more dense and will have more oxygen to be absorbed. For that reason it should increase O2 levels. The other option you probably have is to turn on the Flex option that Dreamstation has. What it does is reduce the pressure for the exhale part of the cycle. With higher pressure on inhale and lower pressure on exhale, more air gets cycled through the lungs on each breath cycle. Flex has steps, and you would be best to try it in steps independed from increasing the max and min pressures, so you know what it is doing. 

I see zero risk in switching to Auto mode if you set the minimum pressure at 5 cm and maximum at 6 cm. Monitor a few nights in SleepyHead to see how that works. I would then increase toward 9 cm in small steps, no more than 1 cm at a time, and monitor for a few nights after each step. You will want to watch for any increase in central apneas, and monitor what changes you get to O2 levels. The idea is to not go higher in pressure than you have to to get the O2 levels up and good AHI results, without too many centrals. 

Make sense?

[Walla Walla]

I would listen to the Doctor not the engineer.

[ColoradoMom]

After reading Ron AKA's post I realize I misspoke. I checked the settings and on my son's machine and the Flex is on and set to 2. Rather than stating that my son's machine was set to a fixed pressure of 6, I should have stated it is in CPAP mode and set at 6. Here are some sleepyhead shots. Thank you again to everybody for your input!

[CHanlon]

So my questions for you why would my son's doctor set his APAP machine at a fixed pressure?

There are a number of reasons, so I'll go with Occam's Razor - "If there are multiple explanations for an occurrence, the simplest one is usually true."  That being... "I was taught to treat OSA with a CPAP."  APAP's are new-fangled devices and many doctors just choose not to learn about them. 

So my questions for you why would my son's doctor set his APAP machine at a fixed pressure? Are there any drawbacks to alternating pressures? 

The history of the apnea treatment business is that the cheapest option, which is a fixed pressure machine, is tried first. This can be driven by insurance company demands or the medical system trying to control costs, or the patient not wanting to spend the $$ if they are on the hook to pay. When you have a fixed pressure machine it is almost always going to be a bit of a compromise, so that is why a titration test is quite important. If the patient treatment is not successful with a fixed pressure machine then they move to an auto pressure next. In short it is money and tradition. 

Ron's correct, but I don't think that's the case here... your son *has* the more expensive APAP machine.  But your doctor - like a lot of them in my area, and my own doctor, in fact, won't prescribe APAP.  Unless there is some factor based on your son's other challenges, I can't see that there would be a reason not to try it.
In Ontario, the machines are paid for under our health care.  An APAP is a little more than the health care coverage will pay so a patient might end up out of pocket by a couple hundred.  All your doctor has to do to justify an APAP for payment is to a) certify that the patient can't tolerate the CPAP, or won't be compliant with a fixed pressure machine or b) show a pressure variance of 5 cm h20 during normal use.  I fall in the second group - and proved it to him with 4 months of data.  He still refused to prescribe one, until I demanded it, and told him I'd buy it outright.

[Ron AKA]

After reading Ron AKA's post I realize I misspoke. I checked the settings and on my son's machine and the Flex is on and set to 2. Rather than stating that my son's machine was set to a fixed pressure of 6, I should have stated it is in CPAP mode and set at 6. Here are some sleepyhead shots. Thank you again to everybody for your input!

CA events do not appear to be a problem at the 6 cm pressure. The worst of the 4 days it was still under 1.0. Most of the events are H's and OA's. They should reduce with a higher max pressure.  I still think as I stated before that moving the setting from CPAP to Auto-CPAP mode with the min pressure set at 5 and the max at 6 cm would be very safe. It is really nothing more than you have done before. It will let the machine set the pressure between those two limits to reduce events as it sees them. This will give you a feel for how the machine will operate if you increase the max up from 6 cm. As I said before do it in small steps of no more than 1 cm, and watch to see if CA's are increasing. Flex is not doing much, and once you settle on the pressure limits you may want to increase it to 3 to see if that helps O2.

[ShaunBlake]

... With CPAP the desaturations have dramatically decreased, but his mean oxygen level is generally about 90. I don't understand why increasing the CPAP pressure after his AHI numbers were good raised his mean oxygen saturation from 90 to 95, so I am hesitant to make changes myself since I really don't understand what is going on. 

I think the best course of action is to wait on APAP until discussing it with the doctor. ..

Dear lady, "Thanks God", as my friend Vlad says, that I was not confronted with the dilemma you are experiencing. I am very very glad that your son is beginning to get treatment. And it seems that you have found some great medical practitioners. Kudos to you all!

I want to relieve your concern about low O2 saturation. 90 is good -- excellent, even. If it never falls below 90, your son will thrive even as a growing teenager. If it dips to 88, for example, and pops right back up, that is an time to watch, not a time to worry. If it dips to 85-88 and remains there for several minutes, that's a time to grow concerned and confront the causes. (I don't know what I would think if it were always at 90-91... I think I'd be concerned but not worried -- but that's not typical; our 02 fluctuates several percentage points.)

So call me a nervous Nellie: I hope you will continue to monitor, update us on the progress, and let your son's doctor steer the treatment. When all is said and done, s/he knows all his conditions, not just those with which we are so familiar.

[Gideon]

I don't believe your sons CA events are currently an issue, but definitely keep an eye on them.
The charts from the nights with the AHI near and over 6 are showing clusters of events.  If this happens regularly then it may be some position induced apnea typically from tucking the chin down.  I bring this up as a talking point with your Doctor.  Many users here have found that a soft loose fitting cervical collar (we are not trying to immobilize the neck) keeps the chin from tucking.  Note that this is not a medically recognized treatment.  You can try some pillow adjustments if these clusters persist.

Frequently varying pressure, APAP/Auto mode, causes CA events to occur.  In this case we frequently suggest fixed pressure which frequently reduces the number of CA events.

I'm not against auto mode, but because of the altitude sleep study indicating "Complex Apnea" ( a mix of obstructive and central apnea) be cautious and slow with pressure changes.

Dialing in treatment is often a trial and error process.  Always know a safe spot (settings) you can go back to.  

Your son has other issues that may or may not impact his apnea therapy and vice versa.

We are here to help in any way we can.

What are the total/run hours on the machine, and the total therapy hours for your son.  They should be almost equal.  I ask this because it is not uncommon to be given a "new" machine with thousands of hours on it.  A trial machine to test the therapy ok, a machine you will keep and use for 5+ years, No!

Fred

[ColoradoMom]

I wanted to provide more clarity to some of the information I have shared. It has been nearly 11 months since a doctor initially diagnosed my son with hypoxia. That diagnosis was based on an overnight oximetery test we got from a DME. My sons average oxygen saturation over the course of the entire night was 90, his lowest levels were in the high 70s, and he was under 88 for 54 minutes. His sleep study and home testing showed similar results, there is some variation from night to night but he always spent more time below 88 than his doctors and I would like to see. My home oxygen testing has shown improvement in his O2 with CPAP. His baseline is still averaging around 90, his lowest saturations are in the low 80s and he is not spending nearly as much time under 88. Before the sleep tech suggested to me that my son would benefit from APAP and a higher pressure I had never considered changing any of my son's machine settings myself. As I mentioned before, my son's sleep doctor has been great. The main problem is that I live in a small town. Appointments and testing are often scheduled months out, my sons doctor is in a different town, and the tests all sent out of town to be read; therefore sometimes it feels like it takes forever to make forward progress.

I'll have my son read thru this thread tomorrow and then I will discuss with him how he would like to proceed. Thank you once again to everyone for all your helpful replies, you have given us good direction and lots to consider and think about!

[Walla Walla]

Raising pressure will only do so much for increasing O2 levels. Normally to increase O2 levels a BiPAP machine is used to increase pressure support allowing for larger exchange of air. The problem is that a large pressure support can lead to an increase in CA events. You might want to ask the Doctor about using Supplemental Oxygen. It's often used with CPAP to keep O2 levels above 90%.