ASV - Patient Initiated Breaths Fall to Zero

My doctor switched me from BiPAP to ASV due to central apneas during the night, but I'm not really sure that its working right. During anytime that I'm trying to fall asleep or wake up during the night, my patient initiated breaths is 85-100%. It falls off sharply once I'm asleep, so that within a couple minutes every breath is machine initiated. My RR rate will then slowly falls to between 8 - 10 where it stays for several hours. When I wake up and change position the same thing will happen again. For example, my AHI is 2.5 last night, but my patient initiated breaths is AVE: 20%, MIN: 0%, MED: 0%.

Has anybody had a similar issue. My doctor recently changed the settings since I was waking up constantly with chest wall pain. The new settings have improved that, but haven't improved the patient initiated breaths. Thanks.

Hi BackwardPawn,

First, I strongly suggest that you fill in your equipement profile.

My ASV don't report patient triggered breath and I don't think I'm experiencing the same problem that you describe. I don't know if I could be of any help but from what I understand so far, it's probably a really good thing that your on ASV.

Since there's only 2 brands that make ASV that I know of, I guess your on a Respironics AutoSV machine?
Is your BPM setting set to auto on your machine?
What was your first pressure setting on ASV?
What are they now?
How long have you been on ASV?
How long have you been on your old BiPAP before ASV?
How did you feel during the day on ASV vs BiPAP so far?

Meanwhile you should arrange a meet with your doc and have him take a look at your data.

Its Respironics AutoSV. I'm not sure what the BPM is, but I'll post my current settings when I get home. I'm not sure how I'd find the original settings were, but I used to get sudden changes in pressure as I dozed off, which kept me awake and would wake up with sore lungs. The respiratory therapist said that my doctor turned the pressure down quite a bit.

Its definitely more comfortable now. The IPAP is still 19 while I'm asleep, but I don't notice sudden changes.

The BiPAP was initially helpful in lowering my AHI from 30 to 7 when I was having a lot of OSA due to a medication side effect. I have a diagnosed neuromuscular condition and a suspected underlying condition that's never been identified. I never felt awake during the day and was treated with Provigil and amphetamines until I couldn't handle the side effects.

As I came off the medication that was causing the obstructives, my centrals shot up, so I'd had an AHI of 15 - 25 with the BiPAP. My AHI with the ASV has been between 2.5 - 5.0, but I still feel really tired during the day.

BPM stands for "Breath Per Minute" or something close to that. I strongly suggest that you start using Sleepyhead software (lots of good ressources here on how to do that). That's the only way we can really see what's going on during your nights. You should also learn to post image here, that would most likely come in handy!

How long before you start ASV after you came off meds?
How long have you been on ASV?

It's look like many people that end up on ASV need more time to feel better (even with extremely good AHI) than those on others xPAP, from what have been reading so far anyway. And unfortunately I'm one of those. There might be room to improve your average AHI but only good Sleepyhead screenshots can help with that in a not too much guessing way.

OK. My BPM starts at 16 while awake and levels out between eight and ten. I do use Sleepyhead, will post some images when I get home today.

Thanks, but there is a BPM setting in your machine and that's what I want to know, not the BPM during the night.

You'll have to go in the "clinical menu" of your machine to see that value. You should look for the "clinical manual" or "provider manual" for your particular machine if you don't already have it. You need it to get access to the clinical menu of your machine. They are available on request on an other apnea forum, a simple google search should get you there.

To understand what is going on, you need to get your machine settings.
Then I would recommend getting both SleepyHead and Encore.
SleepyHead is popular but the display of breathing patterns in Encore is much better.

It sounds as if your breathing is very unstable and the 960 ASV reacts to that with premptive machine initiated breaths.
The parameters in your settings of interest are:

EPAP Min
EPAP Max
PS Min
PS Max
Max Pressure
BPM

Normally, the BPM parameter is set to Auto which allows the machine to select the breathing rate appropriate at the time. If your breath rate slowly declines from 16 while awake, the machine will kick in and initiate breathing. That will keep happening until you initiate a breath.

If you look at an Encore WaveForm report, every breath is shown and, if your rate is unstable, you will be able to see the variation in breath duration. If you sleep all night at a rate of 8-10 BPM, then you might try setting the BPM to 10 or 11 and see if the patient Initiated rate comes down. That will be something to discuss with your doctor.

Later I will post what instability looks like in my data.

JDS74 wrote:To understand what is going on, you need to get your machine settings.
Then I would recommend getting both SleepyHead and Encore.
SleepyHead is popular but the display of breathing patterns in Encore is much better.

I would say that sleepyhead is *vastly* superior for interactive, on the computer use, and encore is superior for printed out use, since sleepyhead doesn't easily allow you to print a detailed chart for the night, and encore doesn't allow you to zoom in and move around and compare the multitude of charts with anything approaching the ease of sleepyhead.

JDS74 wrote:
SleepyHead is popular but the display of breathing patterns in Encore is much better.
Normally, the BPM parameter is set to Auto which allows the machine to select the breathing rate appropriate at the time. If your breath rate slowly declines from 16 while awake, the machine will kick in and initiate breathing. That will keep happening until you initiate a breath.

If you look at an Encore WaveForm report, every breath is shown and, if your rate is unstable, you will be able to see the variation in breath duration. If you sleep all night at a rate of 8-10 BPM, then you might try setting the BPM to 10 or 11 and see if the patient Initiated rate comes down. That will be something to discuss with your doctor.

Later I will post what instability looks like in my data.

If you go with Encore then you'll need to download your SD cards data every time the next day - (MS only, BTW). This will allow you to see the breath by breath waveforms for every night. If you skip one day they just won't be there. A big PITA. Encore is really biased towards a doctor's office and mostly printed out reports from a PDF format. Regarding PDF, zooming in like with SH is really not one of Encores strong points.

The second thing you need to know about Encore is that it allows you only three attempts at a login then it locks down the program until you email the company for an override. If you've got a pirate copy then you need to reinstall and you'll probably lose your past data. Someone else can address that cuz I've never had to do it.

The third thing is that it's a slow slow program even with my i5 processor, not to mention a lot of tricky issues that need to be sorted out and learned (too numerous to go into here), so report back if you go that route, and I'll look for some past posts.

As promised, here is an example of my unstable breathing:

The little dots above the red pressure line represent the machine initiating a breath (ventilator mode). If you are looking for your patterns, then Encore is easier to scan.

Sir NoddinOff is dead when he says that SleepyHead is much easier to upload data because SleepyHead, unlike Encore, will upload all of the data on the card even if you skip a day or two or even a week or two. Encore will upload all of the daily detail data on whatever schedule you select but only the current day's wave data (breathing graphic data) on the day of upload. So, I upload every day to Encore and most days to SleepyHead. Mark, the author of SleepyHead, has included information not provided by Encore, that is valuable to me. For example, he calculates the Inspiratory and Expiratory times and also gives the minimum, maximum and 95% values for the breathing parameters. I find those quite useful. Encore only reports the averages unless you have a Respironics pulse-oximeter installed and then, for heart rate and SpO2 values you get Min, Max and average for those values only.

SleepyHead can import oximeter data from several different CMS models and incorporate those data into the reports. That's very helpful. Encore cannot. So, if you have a CMS oximeter, you have to run those reports separately.

And here are my settings for last night:

Settings
Min EPAP: 12.0
Min Pressure Support: 7.0
Max EPAP: 17.0
Max Pressure Support: 13.0
Max Pressure: 25.0
Flex Setting: 1
Backup Rate: Auto

These allow the machine, in ventilator mode, to switch pressure from 12 cmH2O on exhale to 25 cm H2O on inhale providing adequate air exchange until I start breathing again.

The Breaths Per Minute parameter is called "Backup Rate" and, for most folks, should be set to Auto. That allow the machine the maximum flexibility to provide therapy. The suggestion of setting that to 10 or 11 was for a one night experiment to collect data and see 1) if the Patient Initiated Breaths number gets larger and 2) to get a printout to take to your doctor showing the degree of instability of your breathing at night if that is the cause of the very low PTB% (Patient Initiated Breaths) values you are seeing. Then set it back to Auto.

Sorry I didn't before, but I think I have a clearer picture of what's going on. First my settings:

Max Pressure: 25
EPAP Min: 4
EPAP Max: 12
PS Min: 0
PS Max: 15
BPM: Auto

Thanks for the info about the program, I'll have to download encore and can upload some charts when I find a place to host them.

I think I've figured out whats going on, though. I've been tapering back Prednisone and as I've lowered my dose, my trouble breathing has gotten worse. During the day I'm having trouble taking deep breaths (I went back to the doctor this week because my breath was so limited), at night the unit is forcing me to breath in order to keep my tidal volume high enough. My flow while awake is unstable, but while asleep the machine is doing all the ventilation so its very even, but IPAP is taking 4-5 seconds and EPAP is taking 1 second.

My pulmonary is out this week, so I went to my GP with this info, and because I felt like I was suffocating. They ordered some tests and told me to try an inhaler and stop taking extra anti-inflammatory meds since he thought I had acid reflux. This just made matters worse, though. My sister mentioned to me that it sounded like my pleural lining could be inflammed and they use steroids for that. Since I was a bit desperate, I tried taking prednisone last night and found that I was initiating 30% of the breaths for the first half of the night. By morning it was back to zero and I was struggling to breathe again. I'll have to print off the charts and take this info to the pulmonary when he's back in town.

Thanks for the follow up and I hope you'll be able to find what's going on.

Prednisone has a serum half-life of 2-4 hours. Assuming that for you the two hours is the number, two hours after you took the dose, half of it would be gone and by four hours, only 25% would be left.
That fits in with your increased patient breaths for the first half and nothing the second half when the Prednisone was essentially gone from your system. When next you see you pulmomologist, be sure to bring these reports to him/her and exactly when and what dosage you tried. As a one time experiment it may be OK and you got some good data. But without your doctor's guidance, not a good thing to continue.

I have a love-hate relationship with Prednisone. I desperately want to be rid of it, but something flares up anytime I get down to a reasonable dose. I just spoke with my GPs office to see if I could get a steroid inhailer--they don't think the inflammation is in the airway itself so recommended Prednisone 10 mg, 2x per day until I could get into the pulmonary doctor.

With your GP following, you are good to go.
Keep accurate notes and reports so that you can share what is going on with your pulmonologist.
Perhaps you are on your way to get all this sorted out.