First night with BiPAP Auto SV Advanced

[timbalionguy]

After more than a month of delays, I finally got my BiPAP Auto SV Advanced machine yesterday.

Although I knew the guy at the DME from a previous experience (he likes my VTR collection), there was still a certain amount of 'Even though you know I am going to show you anyway' type stuff, especially with his parent company (Pacific Pulmonary/Peak Sleep). The machine is a rental for the first 9 months, the after that, a single $100 copay. So, that is a very reasonable deal (but not worth a month's wait ). I was not offered the clinician's manuals, nor did I ask for them. The RT was rather amazed that I had purchased my first two machines outright, and that I was buying masks out-of-pocket. (At least he knew what a Innomed Hybrid was.)

As expected, there was little problem setting the machine up. It was preset with my prescription, which the folks at Peak Sleep made me verify over the phone from the DME's office, from the machine's settings. (EPAP Min 8, EPAP max 14, Biflex 2, Min PS 0, max PS 15, Max pres 30, Backup rate 14, Ti 1.2 sec.)

After turn-on and settling into the bed, the machine was immediately busy with constant, unexplained pressure changes. As I learned (again) how to breathe against the machine, there was a combination of SV action, and the Biflex. Within an hour, I realized that the fixed backup rate algorithm was just not going to work for me. Unlike most people, my respiration rate is actually higher when sleeping, and the fixed backup rate was chosen for this condition. Since my rested-but-not-sleeping respiration rate is lower, the machine was mistaking this for abnormally low respiratory rate (The Ti is also probably too short). So, I switched the backup rate to 'auto', and the Biflex completely off. (The Biflex cannot be turned completely off from the user mode, which is kind of odd.) (I think the only reason Biflex was enabled at all was the technician doing my sleep study had been using it, and the doctor simply copied his settings. This may also explain the fixed backup rate, and the short Ti time.) One other interesting thing happened: It had been previously suggested to me to try an EPAP min of 10 vs 8 as prescribed. With Biflex off, it automatically increased to 10.

The settings change resulted in a immediate improvement, and the machine started to behave as expected. Not surprisingly, there was a lot of SV action as I started to get sleepy (which took a while. A combination of the new therapy and the hot room (no time to get A/C installed this weekend) were the main contributing factor.) But, I eventually got to sleep, and I remember snippets of a couple of dreams. One of them dealt with the BiPAP Auto SV machine!

In the morning hours, I found out just how position-dependent my OSA really is. When on either side, the pressure pretty much stayed at EPAP min, and there were just occasional 'shots' from the ASV algorithm. But when I flipped on my back, the ASV events increased, and I could feel EPAP being boosted (in the mode the machine is set up, it functions as an APAP with ASV). The highest I saw EPAP at at any time, was 12. Although I do try and sleep on my side as much as I can, I do occasionally sleep on my back. Now, I know that machine works really hard during those times.

Altough I was happy with how things went last night, there are two outstanding issues: 1.) The humidifier was set perhaps a shade low at 2. At a heat setting of 2, there is only about 8 hours of water in the humidifier. If I set it to 3, I am going to end up adding water in the middle of the night. This is not acceptable. So in the end, I will probably end up getting a different humidifier if I find the current one running out of water. 2.) For all of its sophistication and complexity, this machine gives me no efficacy data at all. I am kind of surprised by this. I will be ordering a card reader and software this evening, as these now become imperative for managing this complex machine.

I do think I felt better this morning. But one night does not a trend make. I suspect it will take some time for everything to get dialed in right before I can say this machine is giving optimal therapy.

[JohnBFisher]

Greetings Fellow ASV-er!

I know you've read Rested Gal's infomration"

Links to Central Apnea
viewtopic.php?p=457566

You have probably read the article about

Ventilation is unstable during drowsiness before sleep onset
http://jap.physiology.org/cgi/reprint/99/5/2036

But it's one thing to read it and quite another to LIVE it with an ASV machine. The next week or two will probably be the hardest for your adjustment. Since you have such a positional response, staying off your back will help.

I do not know how long your apneas would last without the ASV unit. Mine were quite pronounced. In fact my BiPAP unit would just turn off after a minute assuming that I was no longer attached to the mask. So, for me it became reassuring to know that the ASV unit was kicking in and watching over me. I felt I could sleep again.

You will also find that your apneas will start to disappear as the ASV unit starts to retrain your body to breathe normally. It does not eliminate the apnea, but by being so aggressively proactive at keeping your breathing, it helps greatly minimize the problem.

And believe it or not, in a few months you will only barely notice the change in pressure.

So, here's hoping you have many more good nights of sleep.

[OutaSync]

My awake BPM is around 12 and when I go to sleep, I breathe about 20 times a minute. Fortunately the auto works beautifully for both. It still takes me about 45 minutes to an hour to fall asleep on most nights
Bev

[JohnBFisher]

Well, one night does not a trend make. But how about a few nights? How's sleep treating you? I hope you find your sleep as restful as I've been able to find my sleep.

I am happy to report an improvement in my sleep. My neurologist added a medication to my list. As an off label use, it helps improve my sleep architecture. He noted that many neurological issues that tend to impact the brain stem often result in degraded sleep architecture. I was lucky to get 6 hours of sleep. And I was certain I was getting very little REM sleep. But with the medication, my sleep is back toward normal. It appears to be helping. I have doubled the amount of sleep that I am getting. But more importantly, I find I dream much more. (Vivid dreams is one of the side effects that I welcome).

[timbalionguy]

I have been meaning to reply, but have been awfully busy.

The next three nights after that first night have been quite different from the first night.

First of all, the amount of SV action has been a lot less, and occurs at the times it is most expected-- sleep onset, sleeping on back, etc. I have noticed the autoadjust CPAP algorithm working as well, especially for those times on my back. (It is helping me find ways to sleep on my back, which I need to do for at least a few minutes, after several hours on my side.) I am soooo glad I have this machine and not the original BiPAP SV unit.

It is easy to tell when this machine is switching pressures. You hear the motor gradually speed up. This means that practically all of the pressure adjustment is being done by the rotary air gate inside the machine. It must have quite a response range, as the motor speed changes are always very gradual. Even though it is a bit louder than the other two machines I have had, I very much like the sound this machine makes. (I like mechanical sounds when trying to relax, and they don't seem to bother sleep, either. Same with light. I can sleep in a dark or a bright room. I guess its the cat in me. ) Thankfully, I can still hear the lions roar next door, partly due to less sound from the mask's intentional leak at the lower pressures (pressure range on the last machine was 14-18).

The min EPAP pressure returned to 8, for whatever reason, at the beginning of night 2. I knew that the 8 pressure was reasonable, as they had used it in the sleep lab. So for now, I am going to stay with 8 until the software gets here. Once I have that I will be able to tell how effective that low pressure is, and whether I need to think about raising it.

A more careful estimate of humidifier water shows that I can go at least 9 and perhaps 10 hours at heat setting 2. One very annoying thing I discovered is that you have to turn on the humidifier each night. So, on night 2, I had just passover humidification. No problems noted, but I did switch back to heat night 3.

In general, I am definitely sleeping better. I am more alert during the day, especially when not sitting in front of a computer. How much this is a result of SV action when I am asleep, or a much lower overall pressure, I do not know. (Software should be here by weeks' end). It is beginning to look like I am going to have to take this machine, and not my IntelliPAP on the upcoming air trip, which may mean my computer or good camera will have to stay home. This also means I may have to get the 24 volt battery supply right away, as I have a camping trip almost immediately following the trip by air.

As far as adjusting to the machine, it may be that I already largely have. John, you may be right that this machine is teaching me to breathe better. I know it isn't the 'strict taskmaster' that the VPAP Auto SV machine is. But it seems to teach discipline, anyway. (It would be interesting to be able to try the VPAP machine after a few months with the BiPAP. But I suspect I will find the BiPAP better because it is a lot more 'tweakable'.)

One other interesting-- and good- side effect is also sort of weird. I do not tolerate low fat/tending towards vegetarian diets at all. I either won't eat the foods, or eat the wrong low fat (read: high carb) foods because I very much do not like the 'good' vegetables. (I do like the 'bad' vegetables.) Instead, I do quite well on a very low carb diet, done pretty much as a carnivore diet. One of the few adjustments I have to make to eat this kind of a diet long-term is to substitute something like psyllium husks (taken in capsule form) for the fiber I would get from the practically indigestible 'good' vegetables. But for the last year, I would develop constipation after about 5 days or so on the low carb diet, which wasn't a problem pre-CPAP. As a result, I have only been able to hold my weight while on CPAP, rather than begin losing, because I have to frequently interrupt the diet. However, it is looking like the constipation problem may now not be occurring. Too early to tell for sure, but things look encouraging. It will be good to have shed a few pounds before traveling, and being able to get a solid three weeks in of low carb eating will really help. Why was this occurring? I suspect it has something to do with ingested air passing through my digestive tract. There has been little or no air doing this after the first night.

In any case, I think we have a keeper here. But I still need a good deal more experience with this machine to know how it will work long-term with me.

[ldj325]

I am curious for what is behind this statement: "I am soooo glad I have this machine and not the original BiPAP SV unit." Have you used the original and found the Advanced better for you? Or is it for some other reason like the increased data?

Thanks

[timbalionguy]

I am curious for what is behind this statement: "I am soooo glad I have this machine and not the original BiPAP SV unit." Have you used the original and found the Advanced better for you? Or is it for some other reason like the increased data?

Thanks

One of the differences between the original BiPAP SV and the BiPAP SV advanced is the inclusion of an autoadjsting CPAP algorithm in the SV advanced. On the original SV machine, you could either run CPAP, or BiPAP. I am guessing that a majority of the patients using this machine are using some sort of BiPAP modality. But because the EPAP pressure is fixed, it has to be run higher than needed, to cover all apnea and hypopna events. For some people, their needs change nightly, so one night they need a lot of EPAP, the next night, considerably less. (For those who are just learning about bilevel and SV modalities, it is the EPAP (Exhale PAP) pressure that does the work of a normal CPAP in a bilevel modality.

Respironics added the ability for the EPAP to autoadjust in the SV Advanced machine. The IPAP (PSmin) and EPAP track each other, and adjust to OSA-related events. If you turn off the SV modality (PSmin = PSmax), then this machine behaves just like an autoadjusting CPAP or BiPAP.

In my case, the autoadjusting capability is quite important, as I have significant differences in OSA therapy from night to night, mostly for unknown reasons. (Yes, leaks are under control, or accounted for.) The SV modality takes care of central apneas (which also vary over quite a range for me, but are minimal enough that they would not be an issue without the other issues involved), as well as some of the more challenging obstructive events (raises pressure fast enough to immediately correct them). In any case, the autoadjusting featue is definitely doing its thing. Last night at one point, my EPAP pressure was up to around 15. This is the highest continuous pressure I have had with this machine. And the fact that I had just one burst (that I am aware of) of high pressure in 5 nights is a significant improvement over the IntelliPAP. The VPAP Auto 25 wouldn't respond fast enough to some of these events, so although there were nights where it indicated it had ramped up the pressure, the highest I saw it had ramped pressure (on average) in 5 months was just a little under 3 cm. So even though it responded to events, I still did not feel rested the next day.

I can't wait to get the software to see if my theories on how this machine is behaving on me, are correct!

[ldj325]

Thanks Timbalionguy, that was a very clear explanation. Due to economics I have the original autoSV. Fortunately my full face mask acts as a chin strap which in combination with a little weight loss handles most of my OSA, leaving the centrals (CSR) to be handled by the machine (not yet titrated). But inquiring minds do want to know in case an Advanced ever comes along.

[timbalionguy]

Thanks Timbalionguy, that was a very clear explanation. Due to economics I have the original autoSV. Fortunately my full face mask acts as a chin strap which in combination with a little weight loss handles most of my OSA, leaving the centrals (CSR) to be handled by the machine (not yet titrated). But inquiring minds do want to know in case an Advanced ever comes along.

I sure hope you can get that titration soon, and start enjoying some relief. CSR isn't something I would want to try and self-titrate.