(04-08-2016, 08:53 AM)tmoody Wrote: Note: I finally got a copy of my ASV titration study. For the curious, it's attached.

(04-08-2016, 09:59 AM)richb Wrote: I just read through your report. One thing that stands out is that the machine used during the titration had a pressure support max of 15. Is your machine set this way.

Quote: The reason I ask is that while your sleep study focused on Epap settings the Ipap was probably most helpful in stimulating you to breathe. I suggest you download the clinicians manual if you have not already done so. Check your settings for pressure support and report back. One other thing is that the nasal pillows might not be good enough under higher pressures when the machine is working hard.

Edit: It's interesting that the study report recommendations don't mention IPAP pressure at all.

Rich

Quote:I hear you. It's interesting that they chose the nasal pillows for the study (and for the prior diagnostic study); I had never even heard of them before. I used a nasal mask for nine years on CPAP. I have to say, though, that I really like the nasal pillows. I'll only go back to mask if it becomes clear that I have to. Last night I had those leaks, but I'm pretty sure that had to do with the pillow.

The only problem I sometimes have is a little aerophagia when the machine is really pushing hard, but that's not going to be any different with a mask. Same thing goes for the occasional mouth breath.

Or is there some other sense in which you think the nasal pillows might not be good enough?

(04-05-2016, 09:19 AM)tmoody Wrote: As you can see, my AHI went up last night, from 3.8 to 4.2. It's not a huge increase, and the trend for the past three nights has been upward anyway (1.6, 3.3, 3.8, 4.2). Centrals went from zero to 1, not a significant change. PB dropped to .4%, so really the only significant change is another increase in hypos, which is consistent with the recent upward AHI trend. There appears to have been one major OA...151 seconds? if I'm reading it right.

(04-10-2016, 03:35 AM)vsheline Wrote: If there really was an OA for 151 seconds, that would be 2 minutes 31 seconds, which would have been an enormously long OA and quite alarming, really, if it actually happened. Perhaps you are reading it wrong, or perhaps your tiredness from your workout contributed.

Quote:The ASV titration protocol from Respironics which DeepBreathing posted is very clear that the Min EPAP should be increased when obstructive events are observed.

As DeepBreathing has pointed out, hypops are almost always obstructive if occurring during ASV therapy, especially when the Max PS setting is very high, as yours is. When Max PS is high, the ASV algorithm will probably be able to prevent all central events, so any hypops which occur will most likely be obstructive in type.

Quote:I agree with DeepBreathing that it would be advisable to gradually increase Min PS to at least 2 cmH2O (for example, 3 or 4 is more common, I think), and to gradually increase Min EPAP until the hypopneas become rare (less than 1 per hour on average).

I think the plan you described in a more recent post (Min PS set to 1 and Flex set to 2) is a good start, and when it is time for another adjustment I would suggest trying Min PS set to 2, because although I wouldn't expect higher Min PS to help prevent the hypopneas, my general impression from listening to other ASV users is that ASV algorithms tend to work better when the Min PS is set to at least 2 cmH2O.

Quote:One other thing - If feasible, please consider investing in a recording pulse-oximeter, to monitor your average SpO2 at least once in a while. When worn all night, the type worn on the wrist with separate finger sense cup is far more comfortable.

(04-10-2016, 03:35 AM)vsheline Wrote: If there really was an OA for 151 seconds, that would be 2 minutes 31 seconds, which would have been an enormously long OA and quite alarming, really, if it actually happened. Perhaps you are reading it wrong, or perhaps your tiredness from your workout contributed.

If you get a second very long OA (longer than 60 seconds) I would suggest an immediate call to your doctor to discuss an immediate increase in Min EPAP by at least 1 or 2 cmH2O.

The ASV titration protocol from Respironics which DeepBreathing posted is very clear that the Min EPAP should be increased when obstructive events are observed.

As DeepBreathing has pointed out, hypops are almost always obstructive if occurring during ASV therapy, especially when the Max PS setting is very high, as yours is. When Max PS is high, the ASV algorithm will probably be able to prevent all central events, so any hypops which occur will most likely be obstructive in type.

I agree with DeepBreathing that it would be advisable to gradually increase Min PS to at least 2 cmH2O (for example, 3 or 4 is more common, I think), and to gradually increase Min EPAP until the hypopneas become rare (less than 1 per hour on average).

(04-11-2016, 08:53 AM)tmoody Wrote:

(04-10-2016, 03:35 AM)vsheline Wrote: If there really was an OA for 151 seconds, that would be 2 minutes 31 seconds, which would have been an enormously long OA and quite alarming, really, if it actually happened. Perhaps you are reading it wrong, or perhaps your tiredness from your workout contributed.

If you get a second very long OA (longer than 60 seconds) I would suggest an immediate call to your doctor to discuss an immediate increase in Min EPAP by at least 1 or 2 cmH2O.

The ASV titration protocol from Respironics which DeepBreathing posted is very clear that the Min EPAP should be increased when obstructive events are observed.

As DeepBreathing has pointed out, hypops are almost always obstructive if occurring during ASV therapy, especially when the Max PS setting is very high, as yours is. When Max PS is high, the ASV algorithm will probably be able to prevent all central events, so any hypops which occur will most likely be obstructive in type.

I agree with DeepBreathing that it would be advisable to gradually increase Min PS to at least 2 cmH2O (for example, 3 or 4 is more common, I think), and to gradually increase Min EPAP until the hypopneas become rare (less than 1 per hour on average).

I just want to follow up on this.

The long OA did occur. Here's a zoomed screenshot of it:



I haven't seen anything like that before or since. As a general thing, my OAs have been zero since starting on ASV. Once in a while one sneaks through, generally short duration (maybe 15 seconds).

I bumped PSmin up to 2 last night. My AHI was 4.1, all hypos, with some Flow Limitations. Periodic breathing 1.5%.

Interestingly, the previous night's AHI was 3.6, but I felt very ragged yesterday. If I hadn't seen the 3.6 in the morning, I would've guessed it was over 15 (based on experience). Today I feel pretty refreshed. Since my titration study also mentioned a significant number of spontaneous arousals (not apnea-related, I gather), maybe I had a lot of those the night before last.

I'll leave PSmin at 2 for a few days and see what happens. My next adjustment will be to increase EPAPmin from 8 to 8.5 and see if I get any reduction in hypos.

(04-11-2016, 09:51 AM)richb Wrote: It looks to me that the Obstructive event was about 30 seconds long. There is a resumption of breathing at about 1:55.10.

(04-11-2016, 11:15 AM)tmoody Wrote:

(04-11-2016, 09:51 AM)richb Wrote: It looks to me that the Obstructive event was about 30 seconds long. There is a resumption of breathing at about 1:55.10.

I guess I'm reading it wrong. Apparently the OA is followed by a lengthy period of very shallow breathing, lasting several minutes.