Soon to start CPAP - Question on dehydration

[Gideon]

                    picante Titration Study

[Gideon]

                    picante Titration Study

[Gideon]

            picante Titration Study

[Sleeprider]

That's a lot of information, but what stands out is:
1. Oxygen desaturation that qualifies for supplemental oxygen therapy.
2. Extremely fragmented sleep and generally poor sleep efficiency.
3. Severe sleep apnea with mainly obstructive and moderate mixed events that are consequential for O2 desat.
4. The titration study achieved only marginal efficacy at 12 cm with no supine sleep 56 minutes of sleep at the end of the night.
5. The titration is anomalous in that there is no trend for decreasing AHI with increasing pressure. Results are nearly random and suggest better AHI may be achieved at lower pressures.
6. The patient does not tolerate CPAP therapy at the titrated treatment pressure due to aerophagia, and has failed CPAP efficacy so far with high AHI and indications of high chronic flow limitation and poor tidal volume and minute vent.
7. The patient has a complicating health history of myalgic encephalmyelitis.

I think the path forward is fairly clear. Picante should request that her doctor fully review her case with the findings above in mind. Normally this would result in a referral for BiPAP titration, and evaluation of the possible need for oxygen supplemental therapy. The evaluation order should note a lack of efficacy on CPAP to date due to apparent complex apnea, high chronic flow limitations, and aerophagia. Due to complications in this case, picante should request her doctor to consider a titration that evaluates low CPAP pressure with supplemental oxygen as an alternative to CPAP or bilevel at higher pressure. She had low AHI at a CPAP pressure of 6.0, but testing was brief.

My expectation is that she will have a positive response to a combination of low CPAP pressure with supplemental oxygen. Her light, easily disrupted sleep and aerophagia do not easily lend themselves to ASV therapy. Based on what I have seen in this thread so far, and this PSG and titration data, Picante should inform her doctor that she cannot tolerate the CPAP pressure due to aerophagia, continued high AHI and express her desire to identify therapy alternatives.

It is clear that a new therapy strategy is needed, and the current approach of using auto-CPAP at pressures up to 10-12 cm,cannot work due to sleep disruption and discomfort. The use of lower pressure may leave some events untreated, but should improve CA. This is where an oxygen bleed to the CPAP circuit likely becomes a necessary addition.

Picante, the most valuable information you can give your doctor, is to determine through experimentation, the maximum pressure you can tolerate without aerophagia. It may be worthwhile to experiment with much lower pressure to identify that threshold. For example, set your machine to deliver a minimum and maximum pressure of 6.0 with EPR off or set to 1. This may increase obstructive events, but allow you to judge comfort. If it is comfortable, then adding supplemental oxygen is supported by your sleep study. Note, your best results in titration occurred at 6.0 cm, other than the 12 cm, which I noted may be anomalous.

[picante]

OMG, you guys are a team, and you're superheroes on top of that. Supplemental oxygen! That's a revelation. 

I talked with the the sleep doc's office mgr. He's adding more consultation hours in January, and won't be able to see me until then. The one other sleep doc in town doesn't do follow-up. But I'm going to see if I can get in to see the neurologist. She's the referring doc for the sleep studies and nighttime oximetry.

My brain exhaustion is so high I'm off to do a short awake session on CPAP. I've got 2 nights now of non-compliance, and it's helping me reduce gut pain so I can eat. BMI is now 16.6, so ... I tell my dog that she's gotta eat if she wants to keep being a dog. (She's standing right next to me reminding me...)

I'll take a closer look at your analysis when I get some air to my brain. I ordered an oximeter last night.

Sat. night: Total time 2h 5m  (35 minutes of that was separate, awake time -- awake because every inhalation gave me pain in the umbilical region)
25 CAs
3 Hypos
2 Obstructives
3 RERAs

Sun. night: Total time 2h 9 m
29 CAs
6 Hypos
0 Obstructives
1 RERA

Now that I've understood the guidelines posted by Fred, it's staggeringly obvious that CPAP is failing me, at least at pressures this high. Why hasn't the doc noticed? Probably because he's not looking at event distributions.

[Gideon]

Keep in mind that one of the best ways to treat Central Apneas with CPAP is to lower pressure.  I too had misgivings with the prescribed pressure of 12 because it did not seem to "fit" in your titration study.  Sleeprider is extremely good at ASV titrations and management, and if he is saying that is not the way to go, I'll agree.  Julie you have a rather unique list of medical issues.  The issue with apnea is not that you stop breathing multiple times a night, it is that you have Oxygen desats that are associated with that cause.  Technically an event, Apnea or Hypopnea, is not an event unless it is associated with either a desat or an arousal.  Adding Oxygen therapy to your CPAP is another method of managing the desats.  You had desats at all the pressures that they tried during your titration.  I am surprised that they didn't say to start oxygen therapy.  The criteria for that is 5 minutes a night under 88% SpO2, your initial study said 20 minutes <= 88% (61.7 min <= 89%). During your titration study, you had between 31 and 38 desats per hour at pressures from 8 to 11 cmw then fall off to 2 at 12?  I don't buy that as valid.  Your doctor did because the Sleep Lab told him that was best.  The data point at 12 simply does not fit.  I might buy it if there were more data points beyond 12 but there are none.  

Try for comfort at 6 cmw (what sleeprider suggested), and see what your oxygen readings show once you get your meter.  

Fred

[Sleeprider]

ASV is not completely out of the question, and finding the lowest pressure that resolves most obstructive apnea is an important task. My hope is that a significant reduction in events from the diagnostic study can be achieved at low pressure, then oxygen can be used to maintain a healthful blood oxygen level. During the titration test, there were 0 apnea and 3 hypopnea at 6.0 cm, and 1 apnea and 1 hypopnea at 7 cm. All while supine and in the deepest sleep stages achieved. It is amazing how the AHI was 31-43 at pressures of 8, 9, 10 and 11 cm, then inexplicably drops from 43 at 11 cm, to 2 at a pressure of 12, where she only slept on her right side.  As Bonjour says, "I just don't buy that as valid".  Even if 12 cm pressure was working for you, the side effects are intolerable and you have lost weight and are unable to eat.  Now we have the worst case situation where cure is worse than the condition it attempts to treat.

[picante]

You had desats at all the pressures that they tried during your titration.  I am surprised that they didn't say to start oxygen therapy.  The criteria for that is 5 minutes a night under 88% SpO2, your initial study said 20 minutes <= 88% (61.7 min <= 89%). During your titration study, you had between 31 and 38 desats per hour at pressures from 8 to 11 cmw then fall off to 2 at 12?  I don't buy that as valid. 

Fred

Cher Fred, that's a really good point! Although I think those figures come from my overnight pulse oximetry, done at home in August. The neurologist ordered that to see if I needed a sleep study. My pulse ox at the doctor's office is always 98-99%. They just put it into my patient file for the sleep study in October.

The pulse ox graph for my titration study is at the top of the Bilevel Pressure Evolution chart, and it's pretty hard to read, although the tables on the following page give some numbers. Weirdly, it looks like I had far more desat events (12) at 9 cm pressure than at any other pressure, and it's over a time span of only 21 minutes!

During your titration study, you had between 31 and 38 desats per hour at pressures from 8 to 11 cmw then fall off to 2 at 12?

OK, now I'm following you. You did distinguish between August and October.

[picante]

During the titration test, there were 0 apnea and 3 hypopnea at 6.0 cm, and 1 apnea and 1 hypopnea at 7 cm. All while supine and in the deepest sleep stages achieved.  It is amazing how the AHI was 31-43 at pressures of 8, 9, 10 and 11 cm, then inexplicably drops from 43 at 11 cm, to 2 at a pressure of 12, where she only slept on her right side.  

I had not noticed that was supine and also deepest sleep! And look, she kept me at 7 cm for 103 minutes, and only 2 desat events! In fact, that's the lowest desaturation index of the whole titration, except for the highly suspect 12 cm pressure periods.

The right side numbers are even more inexplicable when you consider that I get more GERD symptoms on the right, so at home I sleep almost entirely on my left side. I'm counting sinus constriction as one of the GERD symptoms.

So that brings up my most important question, about determining the max pressure I can tolerate without aerophagia. Do I start low and work my way up? If I'm oxygen starved in the middle of the night, do I raise it? Or is that more likely to be positional?

I'm inclined to start at 7.0 cm tonight. What do you think?

[Sleeprider]

I'm suggesting fixed pressure at 6.0 not auto. The plan is to start at 6.0, and compare that to 7.0, not only for events, but for comfort. Set the minimum and maximum pressures both a 6.0 and set EPR to off or 1.