New to BiPAP - first night of use! (Long post

General Discussion on any topic relating to CPAP and/or Sleep Apnea.
Matt00926
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New to BiPAP - first night of use! (Long post

Post by Matt00926 » Sat Apr 25, 2015 9:16 am

Hello all!

I am using the ResMed AIrCurve 10 VAuto in BiPAP "S" mode at 19/4 with a ResMed Airfit F10 Medium sized full-face mask. I am using the double edge PAP pillow because I cannot sleep on my back for the life of me.

I have restrictive lung disease due to kyphoscoliosis which causes excessive nocturnal hypoventilation and thus both oxygen desaturation and elevated co2 levels (hypercapnia). I also have pulmonary hypertension secondary to hypoxia/sleep disordered breathing and have been suffering for about a year as they put me on PH specific medicines at first which caused terrible ventilation/perfusion mismatches. Suffice to say is I have much incentive to stick to PAP therapy

In my sleep test the pre-treatment (2 hours in length) AHI was 7.0 with 15 hypopneas, 0 obstructive apneas, 0 central apneas and 0 respiratory effort related arrousals. The lowest SaO2 recorded was 73% and CO2 was over 50 for 75% of the time. I have normal blood gas results during day time hours thankfully.

At 20/4 during sleep test titration the AHI index was 0 and the lowest recorded SaO2 was 92% but they ended up using 19/4 because this was when REM sleep was noted (I assume this is important to restfulness).

Last night I wore the BiPAP for 6 hours and the AHI was 3.6 with a reported good mask seal but I did notice a bit of leak when laying on my stomach with my head turned to the side.


My questions:

1) How do I get an AHI of near-zero? I am going to try tightening the mask further so there is a less chance of leakage throughout the night. I am also doing an overnight home pulse oximetry test to record my SaO2 since I had my sleep study done back in October 2014.

2) If you need to adjust the mask or take it off to re position it, should I stop the treatment? Does this cause disturbance in the data if I don't? I want it to be accurate as possible.

3) How do I get more detailed information on my sleep? The Resmed My Air seems very limited in terms of the detail of data reported.


Thank you very much and I apologize for such a lengthy post.
Machine: ResMed AirCurve 10 ST
Mask: Fisher & Paykel Simplus FFM

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robysue
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Re: New to BiPAP - first night of use! (Long post

Post by robysue » Sat Apr 25, 2015 10:17 am

Matt00926 wrote: 1) How do I get an AHI of near-zero? I am going to try tightening the mask further so there is a less chance of leakage throughout the night. I am also doing an overnight home pulse oximetry test to record my SaO2 since I had my sleep study done back in October 2014.
I would not get too worried about trying to get the machine's AHI down to 0.0 every night. If you are awake during part of the night (as many people are), the machine can misscore normal wake breathing patterns as "events". That said, it would be useful to get a better idea of exactly when the events are being scored and what kind of events are being scored. More on that later.

Moreover, it sounds like the real issue in your case are the very long periods with both low O2 concentrations and very high CO2 concentrations. It sounds like getting a recording SaO2 monitor would be a good idea.
2) If you need to adjust the mask or take it off to re position it, should I stop the treatment? Does this cause disturbance in the data if I don't? I want it to be accurate as possible.
The answer is: It depends. If you just need to tug on the mask a bit to let the air cushion reinflate, it's probably best to just do that without turning the machine off. If you need to really move it around to scratch your nose, you might be more comfortable turning the machine off simply so that you're not dealing with a huge blast of air blowing in your face. If you need to actually take the head gear off to fiddle with the headgear or reseat the mask cushion or some other major mask adjustment, then turning the machine off will probably make it easier to do the mask adjustment.

As for a disturbance in the data:

If you turn the machine off, that will be recorded. When you look at the data for the whole night, it will be split into individual "sessions"---one for each period when the machine is on. The overall summary data, however, will be calculated on the full night's data---i.e. it will use all the sessions data added together.

If you don't turn the machine off and you do a lot of moving the mask around, then you may see an official Large Leak recorded in the data. The longer you're fiddling with the mask and the less well sealed the mask is when you're fiddling, the more likely you are to see a large leak show up. There's nothing particularly wrong with a few short lived official Large Leaks, particularly if they correspond to times when you know you were fiddling with the mask.
3) How do I get more detailed information on my sleep? The Resmed My Air seems very limited in terms of the detail of data reported.
Download SleepyHead and learn how to use it. SleepyHead works with the new Resmed A10 machines as far as I know. If SleepyHead doesn't work, then there are forum members who can help you find the most recent version of ResScan, the official Resmed software aimed at DMEs and doctor offices.

Downloading the data from the SD card into SleepyHead will give you a huge amount of very detailed data, including a trace of every single breath you took all night long while you were using the machine. You will see exactly when each event happened, what kind of an event it was, and how long the event lasted. The new Resmed A10 machines also flag periodic breathing, which may be of importance since you have problems with hypercapnia as well as nocturnal hypoventilation. You will easily be able to see your night time respiratory rate, your minute ventilation, and your tidal volume if you download your data into SleepyHead. Those may also be of some importance to you. Finally, before buying an SpO2 monitor, you should peruse the SleepyHead documentation: Some SpO2 montiors are compatible with SH, meaning you can download the SpO2 data and have it displayed along with the data from your Resmed A10.

Once you see your full data displayed in SleepyHead, you will then be in a much better position to decide whether an AHI = 3.6 is really something you need to worry about or whether the events largely seem to be made up of things with a high probability of being misscored wake breathing.

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OkyDoky
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Re: New to BiPAP - first night of use! (Long post

Post by OkyDoky » Sat Apr 25, 2015 10:27 am

If you are looking for Sleepyhead software this is a good site to learn about downloading it. https://sleep.tnet.com/resources/sleepyhead
ResMed Aircurve 10 VAUTO EPAP 11 IPAP 15 / P10 pillows mask / Sleepyhead Software / Back up & travel machine Respironics 760

Matt00926
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Re: New to BiPAP - first night of use! (Long post

Post by Matt00926 » Sat Apr 25, 2015 11:03 am

robysue wrote: I would not get too worried about trying to get the machine's AHI down to 0.0 every night. If you are awake during part of the night (as many people are), the machine can misscore normal wake breathing patterns as "events". That said, it would be useful to get a better idea of exactly when the events are being scored and what kind of events are being scored. More on that later.

Moreover, it sounds like the real issue in your case are the very long periods with both low O2 concentrations and very high CO2 concentrations. It sounds like getting a recording SaO2 monitor would be a good idea.

If you just need to tug on the mask a bit to let the air cushion reinflate, it's probably best to just do that without turning the machine off. If you need to really move it around to scratch your nose, you might be more comfortable turning the machine off simply so that you're not dealing with a huge blast of air blowing in your face. If you need to actually take the head gear off to fiddle with the headgear or reseat the mask cushion or some other major mask adjustment, then turning the machine off will probably make it easier to do the mask adjustment.

As for a disturbance in the data:

If you turn the machine off, that will be recorded. When you look at the data for the whole night, it will be split into individual "sessions"---one for each period when the machine is on. The overall summary data, however, will be calculated on the full night's data---i.e. it will use all the sessions data added together.

If you don't turn the machine off and you do a lot of moving the mask around, then you may see an official Large Leak recorded in the data. The longer you're fiddling with the mask and the less well sealed the mask is when you're fiddling, the more likely you are to see a large leak show up. There's nothing particularly wrong with a few short lived official Large Leaks, particularly if they correspond to times when you know you were fiddling with the mask.

Download SleepyHead and learn how to use it. SleepyHead works with the new Resmed A10 machines as far as I know. If SleepyHead doesn't work, then there are forum members who can help you find the most recent version of ResScan, the official Resmed software aimed at DMEs and doctor offices.

Downloading the data from the SD card into SleepyHead will give you a huge amount of very detailed data, including a trace of every single breath you took all night long while you were using the machine. You will see exactly when each event happened, what kind of an event it was, and how long the event lasted. The new Resmed A10 machines also flag periodic breathing, which may be of importance since you have problems with hypercapnia as well as nocturnal hypoventilation. You will easily be able to see your night time respiratory rate, your minute ventilation, and your tidal volume if you download your data into SleepyHead. Those may also be of some importance to you. Finally, before buying an SpO2 monitor, you should peruse the SleepyHead documentation: Some SpO2 monitors are compatible with SH, meaning you can download the SpO2 data and have it displayed along with the data from your Resmed A10.

Once you see your full data displayed in SleepyHead, you will then be in a much better position to decide whether an AHI = 3.6 is really something you need to worry about or whether the events largely seem to be made up of things with a high probability of being misscored wake breathing.
Thank you so much for a great informative reply. In viewing the data from SleepyHead it looks like obstructive apneas were 3.54/3.65 and hypopneas were only .11/total 3.65 AHI. This seems to mean that the PAP therapy is adequately addressing hypopneas. I assume it's more informative to look at weekly trends instead of a single day as a data point. From what I've read an AHI under 5 is considered normal. Are there any potential reasons why I previously scored an AHI of zero and an AHI of 3.65 this time?
Machine: ResMed AirCurve 10 ST
Mask: Fisher & Paykel Simplus FFM

Matt00926
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Re: New to BiPAP - first night of use! (Long post

Post by Matt00926 » Sat Apr 25, 2015 11:10 am

OkyDoky wrote:If you are looking for Sleepyhead software this is a good site to learn about downloading it. https://sleep.tnet.com/resources/sleepyhead

Thanks! I am watching You Tube tutorials on how to really understand all this data!
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Re: New to BiPAP - first night of use! (Long post

Post by Pugsy » Sat Apr 25, 2015 2:56 pm

Matt00926 wrote:Are there any potential reasons why I previously scored an AHI of zero and an AHI of 3.65 this time?
Any number of reasons.

1...we don't sleep the same each night
2...in the sleep lab they would have removed any awake/semi awake events from the calculations
3...in the sleep lab they can quickly adjust the settings as needed but these machines can't adjust that quickly and in your case the S mode won't adjust anyway.

Don't worry about 0.0 AHI right now. Look at SleepyHead and see how much of your AHI is Clear Airway Index (Centrals) because you have to mentally remove the CA Index from the AHI when evaluating pressure needs because we don't try to fix centrals with this type of machine.

AHI of 0.0 doesn't guarantee a person anything but maybe a chance to pat themselves on the back.
Yeah it's nice to see it but it's hard to obtain because these machines are just so sensitive and often a handful of awake breathing irregularities get flagged (these machines don't know if we are asleep or awake) and there's nothing we an do about it.

If you look at your SleepyHead reports and you see some events flagged real close to know awake times there's a good chance that those events aren't real but instead are just the machine mislabeling awake/semi awake breathing.

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Re: New to BiPAP - first night of use! (Long post

Post by Matt00926 » Sat Apr 25, 2015 3:34 pm

Pugsy wrote:
Matt00926 wrote:Are there any potential reasons why I previously scored an AHI of zero and an AHI of 3.65 this time?
Any number of reasons.

1...we don't sleep the same each night
2...in the sleep lab they would have removed any awake/semi awake events from the calculations
3...in the sleep lab they can quickly adjust the settings as needed but these machines can't adjust that quickly and in your case the S mode won't adjust anyway.

Don't worry about 0.0 AHI right now. Look at SleepyHead and see how much of your AHI is Clear Airway Index (Centrals) because you have to mentally remove the CA Index from the AHI when evaluating pressure needs because we don't try to fix centrals with this type of machine.

AHI of 0.0 doesn't guarantee a person anything but maybe a chance to pat themselves on the back.
Yeah it's nice to see it but it's hard to obtain because these machines are just so sensitive and often a handful of awake breathing irregularities get flagged (these machines don't know if we are asleep or awake) and there's nothing we an do about it.

If you look at your SleepyHead reports and you see some events flagged real close to know awake times there's a good chance that those events aren't real but instead are just the machine mislabeling awake/semi awake breathing.
Thanks for the information. I checked and CAI is zero. I was also using the BiPAP during the day a bit while awake just to try it out and get used to it so I am sure that causes some variance in the overall picture. I also had fragmented sleep where I woke up every hour or two.

I'm set to use the BiPAP for three months before I see my sleep doctor again, so I assume he will see any good or band trends and make moves to adjust.

I wish I could use the BiPAP in the auto mode so it would adjust the pressures as needed, would probably help me fall asleep as well.
Last edited by Matt00926 on Sat Apr 25, 2015 3:37 pm, edited 1 time in total.
Machine: ResMed AirCurve 10 ST
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Papit
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Re: New to BiPAP - first night of use! (Long post

Post by Papit » Sat Apr 25, 2015 3:36 pm

Pugsy wrote:
Matt00926 wrote:Are there any potential reasons why I previously scored an AHI of zero and an AHI of 3.65 this time?
Any number of reasons. . . .

2...in the sleep lab they would have removed any awake/semi awake events from the calculations . . . .
AHI of 0.0 doesn't guarantee a person anything but maybe a chance to pat themselves on the back.

Yeah it's nice to see it but it's hard to obtain because these machines are just so sensitive and often a handful of awake breathing irregularities get flagged (these machines don't know if we are asleep or awake) and there's nothing we an do about it. . . .
I'm not familiar with Respironics' "sleep tab," Pugsy. It sounds like it improves the accuracy of sleep performance measurements.
ResMed and other machines use the inappropriate-for-sleep-calculations (e.g., AHI and Flow Limitations) data that is recorded beginning immediately after turning ON the xpap and during the waking-up period in the morning. Any idea why their bright engineers by now have not provided a feature to automatically exclude the first and last 10/20/30 minutes (selectable by the doctor or sleep tech) to significantly improve the accuracy of sleep performance parameter results? While not perfect, even as approximations, the 10/20/30-minute data exclusion would significantly limit how much inappropriate awake data at the beginning and end of the night is used in sleep calculations, thereby making the calculations more accurate and reflective of the patient's sleep.

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Re: New to BiPAP - first night of use! (Long post

Post by robysue » Sat Apr 25, 2015 8:07 pm

Papit wrote:
Pugsy wrote:these machines are just so sensitive and often a handful of awake breathing irregularities get flagged (these machines don't know if we are asleep or awake) and there's nothing we an do about it. . . .
I'm not familiar with Respironics' "sleep tab," Pugsy. It sounds like it improves the accuracy of sleep performance measurements.
Don't know what you mean by Resprionics' "sleep tab". The PR machines are just like all the rest: They don't know when you are awake and when you are asleep, and they score anything that meets the algorithm's definition of an "event".

The F&P Icons with SenseAwake claim to be able to tell when you are awake and they automatically lower the pressure until the machine thinks you are asleep. I do know that the Icons keep track of the number of times the SenseAwake algorithm kicks in; in other words the Icon attempts to tell you how many times you woke up during the night. I have no idea how accurate the SenseAwake algorithm is. I also don't know if the Icons score apnea and hypopnea events during a "SenseAwake" event.
ResMed and other machines use the inappropriate-for-sleep-calculations (e.g., AHI and Flow Limitations) data that is recorded beginning immediately after turning ON the xpap and during the waking-up period in the morning. Any idea why their bright engineers by now have not provided a feature to automatically exclude the first and last 10/20/30 minutes (selectable by the doctor or sleep tech) to significantly improve the accuracy of sleep performance parameter results?
The ResMed machines do not record events if the ramp is on. However I don't know if they include the ramp time as part of the "sleep time" for the purposes of calculating the AHI data.

There are some problems with a 10/20/30 minute "exclusion" window at the beginning and ending of the night. Some folks have widely different sleep latencies on different nights; they might be asleep in 5 minutes one night, but it may take them 30 minutes to get to sleep the next night. Same thing in the morning. Some people are more prone to dozing with the mask before getting up than others, but how long one dozes may be very dependent on which day of the week it is. Another problem is that some of us have a pattern of falling asleep rather quickly at the beginning of the night (as in less than 5 minutes), but then waking up about 10-20 minutes after we first fell asleep. But a bigger problem is that many people will turn the machine off and back on more than once during the night. And these wakes and the return to sleeps following them are often both qualitatively and quantitatively different than when you first fall asleep at the beginning of the night and when you finally wake up for good in the morning: It may take you 20 minutes at the beginning of the night to get to sleep; but after you turn the machine off, get up to go to the bathroom, it may only take you 2 minutes to fall back asleep after you return to bed and turn the machine back on. And if the machine were programmed to ignore the first and last 10/20/30 minutes of each session, that can add up to a lot of time that may represent actual sleep time because the person turned the machine off just as soon as they were startled awake (possibly by an apnea or hypopnea that got through the CPAP defenses.)

While not perfect, even as approximations, the 10/20/30-minute data exclusion would significantly limit how much inappropriate awake data at the beginning and end of the night is used in sleep calculations, thereby making the calculations more accurate and reflective of the patient's sleep.
My best quick guess (as a mathematician) is that for most people there would not be a significant improvement in accuracy of the calculations. There are several things driving potential inaccuracies in the data, and some of them kind of run counter to each other:
  • Wake time causes the run-time to overestimate the sleep time.
  • If there are no or relatively very few events scored during wake time, the calculated AHI based on run-time underestimates the AHI slightly. As an example, let's suppose the machine is run for 8 hours, the CPAPer is actually awake for a total of 60 minutes during the night (including latency to sleep and any dozing in the morning.) Let's suppose the machine records a total of 12 events during the 8 hours and let's suppose that 1 of them occurred while the PAPer was awake. The calculated AHI = 12/8 = 1.5. The "true" AHI = 11/7 = 1.57.
  • If there are a (relatively) modest number of events scored during wake, the calculated AHI based on run-time may modestly overestimate the AHI. As an example, let's suppose the machine is run for 8 hours, the CPAPer is actually awake for a total of 60 minutes during the night (including latency to sleep and any dozing in the morning.) Let's suppose the machine records a total of 12 events during the 8 hours and let's suppose that 3 of them occurred while the PAPer was awake. The calculated AHI = 12/8 = 1.5. The "true" AHI = 9/7 = 1.28.
  • If there are relatively a lot of events scored during wake, the calculated AHI based on run-time may significantly overestimate the AHI. As an example, let's suppose the machine is run for 8 hours, the CPAPer is actually awake for a total of 60 minutes during the night (including latency to sleep and any dozing in the morning.) Let's suppose the machine records a total of 12 events during the 8 hours and let's suppose that 6 of them are occurred while the PAPer was awake. The calculated AHI = 12/8 = 1.5. The "true" AHI = 6/7 = 0.86.
The upshot of these kinds of calculations:

By simply taking run-time as a proxy for sleep time, the machine is mainly erring on the side of caution: If there are a lot of "wake events", the machine scored AHI will overestimate the true AHI. If there are very few "wake events" and the amount of "wake time" is roughly average (as in you are asleep for at least 85% of the time the machine is on), then the calculated AHI may be a slight underestimate, but it will be pretty accurate. In either case, we can conclude that if the machine AHI is in the target range of less than 5, then the real AHI for the night was also in the target range of less than 5.

So unless you happen to be in the relatively small group of people whose wake breathing is frequently misscored as sleep disordered breathing, the machine's calculated AHI is probably pretty close to your real AHI. And even if your wake breathing is frequently misscored as sleep disorderd breathing, the machine's calculated AHI will give you a very practical upper bound on what your true AHI was for the night.

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Re: New to BiPAP - first night of use! (Long post

Post by Papit » Sat Apr 25, 2015 10:55 pm

robysue wrote: Don't know what you mean by Resprionics' "sleep tab". The PR machines are just like all the rest: They don't know when you are awake and when you are asleep, and they score anything that meets the algorithm's definition of an "event".

The F&P Icons with SenseAwake claim to be able to tell when you are awake and they automatically lower the pressure until the machine thinks you are asleep. I do know that the Icons keep track of the number of times the SenseAwake algorithm kicks in; in other words the Icon attempts to tell you how many times you woke up during the night. I have no idea how accurate the SenseAwake algorithm is. I also don't know if the Icons score apnea and hypopnea events during a "SenseAwake" event.
. . .

Ok, got that, thanks. All mfr's machines (MAYBE with the possible exception of F&P and their SenseAwake claim) introduce some small inaccuracy in their sleep performance calculations by recording 'sleep "disorders"' during awake periods. (Disregard my sleep tab comment: My bad. I misread Pugsey's "sleep lab" comment as "sleep tab.")

I see how complicated it is to try to provide a means to reduce the (however small) inaccuracy. Your observation that "disorders" are not scored during the tech or user preset EPR period (expiratory pressure relief of 1, 2 or 3 cmH20) provides an added reason that encourages use of EPR. For any interested readers, do you know how long EPR's last and are they the same time duration for all three setting levels? I looked but couldn't find that.

Thanks again for thinking it out and walking us through this.

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Re: New to BiPAP - first night of use! (Long post

Post by robysue » Sat Apr 25, 2015 11:19 pm

Papit wrote: I see how complicated it is to try to provide a means to reduce the (however small) inaccuracy. Your observation that "disorders" are not scored during the tech or user preset EPR period (expiratory pressure relief of 1, 2 or 3 cmH20) provides an added reason that encourages use of EPR.
You are confusing EPR and the ramp. The Resmed machines do not record events during the ramp period. The ramp is not the same as the EPR. The ramp starts the pressure setting at a level lower than the therapeutic setting (or min pressure setting if you are using APAP mode) and it increases the pressure up to the therapeutic setting (or min pressure setting if you are using APAP mode.) The ramp period can be set to last from 5 minutes to 40 minutes in 5 minute increments.

EPR is exhalation pressure relief and EPR is what what lowers the pressure on exhalations by a fixed amount. EPR can be set to be active in the ramp period only OR EPR can be set to be active all night long. Most folks who use EPR around here use it all night long.
For any interested readers, do you know how long EPR's last and are they the same time duration for all three setting levels? I looked but couldn't find that.
The decrease in pressure because of EPR lasts from the time the machine detects the beginning of the exhalation until the machine detects the beginning of the inhalation. As soon as you start to inhale, the pressure is increased back up the therapeutic setting. That's why it's called exhalation pressure relief---it "relieves" (reduces) the pressure during your exhalations. That's true in all three EPR settings.



Thanks again for thinking it out and walking us through this.[/quote]

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Machine: DreamStation BiPAP® Auto Machine
Mask: Swift™ FX Nasal Pillow CPAP Mask with Headgear
Additional Comments: PR System DreamStation and Humidifier. Max IPAP = 9, Min EPAP=4, Rise time setting = 3, minPS = 3, maxPS=5