Apnea More Severe; Prescribed Pressure Decreased

[fwg1947]

Background
I am new to this forum, but not to CPAP therapy.  I had an overnight diagnostic Sleep Study in 2009 which indicated mild obstructive sleep apnea with AHI 11 (event totals were Obstructive=86; Central=1; Mixed=0; Hypopnea=38).  Moderate obstructive sleep apnea related oxygen desaturations observed to a low of 82%.  Moderate sleep disruption due to obstructive sleep apnea or spontaneous arousals, with an arousal index of 24 per hour.  Distorted sleep architecture.  I started CPAP therapy with mask fitting and machine titration done by my DME provider's respiratory therapist.  After an extended period of mask trials and a major problem with large leaks, the treatment began to show good results with fixed CPAP pressure of 9.0 and nasal pillows.  CPAP therapy continued unchanged for over seven years with a long term AHI of less than 2.0 and much higher quality of sleep.

I changed from private insurance to Medicare in January 2017 and sought to obtain needed CPAP supplies.  Because of my original sleep doctor's inability to provide certain documentation required by Medicare, I had to have a new sleep study performed. 

New Sleep Study
A new overnight split study was done at a sleep lab on 5/1/17.  The diagnostic portion of the study indicated 48 respiratory events consisting of 2 obstructive apneas, 0 mixed apneas, 12 central apneas, and 34 hypopneas.  The average event duration was 22 seconds, and the maximum duration was 47 seconds.  The average baseline for oxygen desaturations was 96% and the minimum SaO2 during a desaturation event was 82%.  Blood oxygenation was 4% or more below baseline 194 times for a total of 119.7 minutes.  The titration portion of the study started with pressure of 5 cmH2O and reached a final pressure of 7 cmH2O.  The AHI at this pressure was 0 with lowest oxygen saturation of 94%.

The sleep doctors' diagnosis was (1) moderate obstructive sleep apnea with AHI 21, (2) Hypoxemia with lowest O2 saturation of 82%, and (3) excessive daytime sleepiness.

I continued therapy with my old machine at 9.0 cmH2O until I obtained a new machine and supplies on 5/31/17.  From that night through last night I have been on fixed CPAP pressure of 7 cmH2O for a total of 44 nights, with not so good results. AHI for the whole period is 9.93, with the lowest daily AHI being 1.75 and the highest being 56.15.  My machine shows mask fit of 99% to 100% throughout this period, which I understand to mean that large leaks are not an issue.  The highest AHI numbers occurred during a consecutive 5 day period while in Colorado and New Mexico (altitude 7,000 to 7,700 ft.):  17.39, 16.80, 22.49, 56.15, 41.96.  My home altitude is 700 ft.  My CPAP machine manual states that it adjusts automatically for altitude up to 7,500 ft.

Questions
(1)  Does my prescription of CPAP fixed pressure 7.0 make sense considering that per the 2 sleep studies, my apnea has progressed from mild to moderate, and considering that I had an acceptable (i.e., <5.0) long-term AHI of 1.9 at a pressure of 9.0 for the 7 plus years leading up to the new sleep study?

(2)  I will be returning to high altitude at least twice a year to visit family.  What can I do to prevent the extremely high AHI numbers that occurred on my recent trip?

[robysue]

I continued therapy with my old machine at 9.0 cmH2O until I obtained a new machine and supplies on 5/31/17.  From that night through last night I have been on fixed CPAP pressure of 7 cmH2O for a total of 44 nights, with not so good results. AHI for the whole period is 9.93, with the lowest daily AHI being 1.75 and the highest being 56.15.  My machine shows mask fit of 99% to 100% throughout this period, which I understand to mean that large leaks are not an issue.  The highest AHI numbers occurred during a consecutive 5 day period while in Colorado and New Mexico (altitude 7,000 to 7,700 ft.):  17.39, 16.80, 22.49, 56.15, 41.96.  My home altitude is 700 ft.  My CPAP machine manual states that it adjusts automatically for altitude up to 7,500 ft.

Questions
(1)  Does my prescription of CPAP fixed pressure 7.0 make sense considering that per the 2 sleep studies, my apnea has progressed from mild to moderate, and considering that I had an acceptable (i.e., <5.0) long-term AHI of 1.9 at a pressure of 9.0 for the 7 plus years leading up to the new sleep study?

Sounds to me like the titration part of the split study didn't allow you enough time to get into a nice long REM cycle. Or you didn't sleep as much on your back. Or whatever.  And the result is that you were left under titrated.

If this were my data, I'd just quietly get the clinical manual for the new machine and change the settings to CPAP @9cm and see if the numbers go back to what they were on the old machine.

(2)  I will be returning to high altitude at least twice a year to visit family.  What can I do to prevent the extremely high AHI numbers that occurred on my recent trip?

Not sure about this.  But I'll take a stab.

First, I'd make sure that the CPAP was set to 9cm rather than 7cm. Next, I'd evaluate the data after each night at high altitude.  If the AHI goes up substantially AND the increase is due to OAs and Hs, then I'd increase the pressure 1 or 2 cm and see if that helps.  If the AHI goes up substantially but the reason is that all of a sudden you have a whole bunch of CAs, I'm not sure there's much you can do. In that case, I'd report the problem to my sleep doc when I got back and see if s/he has any ideas on what to do on future visits.

[Gideon]

IMHO you need to titrate the best response at altitude then subsequently change the settings when you go to altitude and change them back when you return.
What length of time will you be at altitude each visit/per year?

Altitude will impact your AHI, and frequently we see an increase, as Robysue indicates, in CA events.

[ajack]

I would download the sleepyhead program at the top of the page and get a chart up for the forum to advise on. The centrals that have developed since your first sleep test may be an issue.

[fwg1947]

IMHO you need to titrate the best response at altitude then subsequently change the settings when you go to altitude and change them back when you return.
What length of time will you be at altitude each visit/per year?

Altitude will impact your AHI, and frequently we see an increase, as Robysue indicates, in CA events.

My trips to Colorado and New Mexico will be no longer than a week to 10 days per visit.  Not very long to adjust to the altitude.  My AHI was 1.75 for the night I got home from the last trip, compared to AHI of 41.96 for the last night at high altitude, with no change in machine settings.

[fwg1947]

I have the SleepyHead program downloaded and installed.  I will post data soon.

[fwg1947]

I continued therapy with my old machine at 9.0 cmH2O until I obtained a new machine and supplies on 5/31/17.  From that night through last night I have been on fixed CPAP pressure of 7 cmH2O for a total of 44 nights, with not so good results. AHI for the whole period is 9.93, with the lowest daily AHI being 1.75 and the highest being 56.15.  My machine shows mask fit of 99% to 100% throughout this period, which I understand to mean that large leaks are not an issue.  The highest AHI numbers occurred during a consecutive 5 day period while in Colorado and New Mexico (altitude 7,000 to 7,700 ft.):  17.39, 16.80, 22.49, 56.15, 41.96.  My home altitude is 700 ft.  My CPAP machine manual states that it adjusts automatically for altitude up to 7,500 ft.

Questions
(1)  Does my prescription of CPAP fixed pressure 7.0 make sense considering that per the 2 sleep studies, my apnea has progressed from mild to moderate, and considering that I had an acceptable (i.e., <5.0) long-term AHI of 1.9 at a pressure of 9.0 for the 7 plus years leading up to the new sleep study?

Sounds to me like the titration part of the split study didn't allow you enough time to get into a nice long REM cycle. Or you didn't sleep as much on your back. Or whatever.  And the result is that you were left under titrated.

If this were my data, I'd just quietly get the clinical manual for the new machine and change the settings to CPAP @9cm and see if the numbers go back to what they were on the old machine.

(2)  I will be returning to high altitude at least twice a year to visit family.  What can I do to prevent the extremely high AHI numbers that occurred on my recent trip?

Not sure about this.  But I'll take a stab.

First, I'd make sure that the CPAP was set to 9cm rather than 7cm. Next, I'd evaluate the data after each night at high altitude.  If the AHI goes up substantially AND the increase is due to OAs and Hs, then I'd increase the pressure 1 or 2 cm and see if that helps.  If the AHI goes up substantially but the reason is that all of a sudden you have a whole bunch of CAs, I'm not sure there's much you can do. In that case, I'd report the problem to my sleep doc when I got back and see if s/he has any ideas on what to do on future visits.



I changed the pressure setting to 9.0 as you suggested.  Tonight will be the first data at the higher pressure.  Thanks for all the advice.

[Sleeprider]

IMHO you need to titrate the best response at altitude then subsequently change the settings when you go to altitude and change them back when you return.
What length of time will you be at altitude each visit/per year?

Altitude will impact your AHI, and frequently we see an increase, as Robysue indicates, in CA events.

My trips to Colorado and New Mexico will be no longer than a week to 10 days per visit.  Not very long to adjust to the altitude.  My AHI was 1.75 for the night I got home from the last trip, compared to AHI of 41.96 for the last night at high altitude, with no change in machine settings.

Are your events predominately central (CA), or obstructive (OA).  Hypopnea could go either way, but your recent sleep study results suggest you may have developed a more complex apnea problem with centrals rather than simple obstructive apnea.  The appropriate recommendation differs depending on the type of event.  Since you spent considerable time at higher altitude, it CA events are more likely, and hopefully they are lower when you are at your normal altitude.

#Sleepyhead is free, and can give you the information we all need to guide you in dealing with the apnea as well as with the medical system.

[fwg1947]

[quote pid='214281' dateline='1500082936']
Are your events predominately central (CA), or obstructive (OA).  Hypopnea could go either way, but your recent sleep study results suggest you may have developed a more complex apnea problem with centrals rather than simple obstructive apnea.  The appropriate recommendation differs depending on the type of event.  Since you spent considerable time at higher altitude, it CA events are more likely, and hopefully they are lower when you are at your normal altitude.

[url=http://OSCAR Official Download Page ----> CLICK HERE ./]SleepyHead[/url] is free, and can give you the information we all need to guide you in dealing with the apnea as well as with the medical system.

[/quote]

For the first 31 days on the new CPAP machine at 7.0 pressure, CA events averaged 12.6 nightly; OA events averaged 8.6 nightly, and H events averaged 57.9 nightly.  This time period included the several days at high altitude.  The worst night at altitude had 131 CA events, 40 OA events, and 256 H events.

I have SleepyHead installed and will post data soon.  Thanks for your help.

[robysue]

fwg1947,

You said you were going to bump the pressure on the new machine back up to what you were using on the old machine last night. What do last night's numbers look like?