In this post, I am going to stay as BASIC as possible. That works well for me, because I only have a basic understanding. Therefore, this post will probably have something for everyone. A "little" understanding for Newbies and a good laugh for the more experienced!Grand-PAP wrote:This is instalment THREE of my Rocky Road. It's a little long, so feel free to take a detour!
1st Post: viewtopic.php?f=1&t=75762&p=692914&hili ... d+#p692914
2nd Post: viewtopic.php?f=1&t=77531&p=706282#p706282
Importand Caveat: I am NOT suggesting than anyone read this and decide to venture into this degree of self-directed therapy.
In the prior post, I indicated that I would provide information regarding pressure changes and compare and contract the S9 with the S1.
On the S9 VPAP my initial pressures were:
EPAP: 6
Min PS: 3
Max PS: 8
Over time I made three adjustments:
6, 3, 10
6, 4, 11
6, 4, 14
I have had those settings for a couple of weeks and they have virtually eliminated all events.
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On the S1 my Rx settings were:
Mode: AutoSV
Max Pressure: 25.0 cm H20
Max EPAP: 15 cm
Min EPAP: 8.0 cm
Max PS: 15 cm
Min PS: 4.0 cm
I kept the Doc’s Rx for the first three weeks, with only minor adjustments to the EPAPs. The minor adjustments worked well to reduce the OAs and CAs, but I still had large numbers of hypopneas and pressure pulses. At that point, I felt both the S9 and S1 were pretty much doing their jobs well, with the exception of the hypopneas and pressure pulses. Then on April 20th, I began the experiment below.
Well, I would like to discuss a special “ASV” machine – A STRAIGHT CPAP MACHINE WITH ASV.Pugsy often talks about the bi-level machines being “three machines in one” -- CPAP, APAP and Bi-Level.
I began my therapy on a straight CPAP machine set at 10cm H2O.
As with most people, I experimented with EPR (Expiration Pressure Relief). It worked fine, but I quickly realized that I didn’t need the reduced pressure, because I had no problem exhaling against the 10cm. So, I turned the EPR off. A little over a month ago, I got a PR System One BiPAP autoSV Advanced Machine.
NOW: My first BASIC Primer:
Min IPAP = Current EPAP plus Min PS
Max IPAP = Current EPAP plus Max PS
Therefore: My IPAP could range between 12 cm and 25 cm:
12 (Min EPAP of 8 + Min PS of 4)
25 (Max EPAP of 15 and Max PS of 15) -- NOT 30 because Maximum Pressure is 25
If my last EPAP were 8 AND I DID NOT INHALE, the ASV would begin to increase pressure and pulse to cause me to take the breath. So, it could quickly change from 12 cm (Min EPAP + Min PS of 4) to 25 cm. Then when it was successful at dealing with the CA, it could rapidly drop back down to Min EPAP of 8. That didn’t bother me when I was asleep, but during the early evening, before going to sleep, with “normal” position movement and/or irregular breathing the machine would start the pressure pulsing process. The comedian, Jim Carey, had a routine where he used a bathroom plunger to “pump” his mouth. I often envisioned that when the PR was rapidly toggling up and down with pressure changes. It became very irritating.
On April 19th, I was on a phone conversation with another cpaptalk ASV member and we were discussing this issue. His experience on straight CPAP was similar to mine and he also did not have difficulty with CONSTANT inhale and exhale pressure. I mentioned to him that I had considered turning my autoSV into a "Straight CPAP with ASV", by raising my Min EPAP to my CPAP pressure of 10 cm and setting my Min PS to ZERO.
The THEORY was:
1. With “normal” breathing Min EPAP would be 10 and Min IPAP would be 10 –- a straight CPAP.
2. When the machine determined that I had not taken a breath, the ASV would kick in and move the IPAP from 10 to a max of 25, as needed.
3. It would shorten the pressure range increase by 2 cm (Min EPAP of 8 to Min EPAP of 10).
4. When returning after inhalation occurred, it would not have to drop as far – back to Min EPAP of 10 instead of 8.
5. Because of #3 and #4, the up and down pressure movement should be more comfortable.
Neither of us knew if it would work or not. He bit immediately and did the PS change that night. I didn’t do it until the next day. A couple of days later we compared notes and not only did it work, but both of us felt it was considerable more comfortable. I have had those setting since the experiment.
So, that was the experiment.
Now for some of the justification and results:
In the early stages of therapy I was making the “normal cpaptalk member” adjustments of EPAP Min and/or Max to address both Obstructive and Clear Airway Apneas. Those adjustments were successful, but not germane to this post. I had two issues that I was trying to address:
1. Extremely high hypopneas
2. Huge numbers of pressure pulses
Here's where my ignorance shines through, but I felt that if I could eliminate some of the pressure variations and reduce the range of pressures between EPAP and IPAP, that I might see improvement in both the Hypopneas and Pressure Pulses. Below I have pasted two graphs:
Consider this graph. This was before I ZEROed out the PS. My feeble analysis was that I had major pressure variations and a huge number of pressure pulses.
Then, consider this graph where the only change was ZERO Min PS. It flattened the pressure variations and virtually eliminated the Pressure Pulses:
OK, this is when you experts laugh! I don't know if I am dreaming or not, but it seems to work.
Finally consider this:
The first 28 days, I had the Min PS at 5. For that 28 day period, I had a HI of 3.5 and an average of 90.3 Pressure Pulses per hour. For the 12 days after Zero Min PS, I had HI of 1.5 and 14.5 Pressure Pulses per hour.
Sometime I think we get caught up in dealing with Indexes and miss a bigger picture. Those two Pressure Pulses figures of 90.3 per hour and 16.7 per hour can be a little misleading. Forgetting "averages" for a minute, prior to reducing the Min PS to ZERO, the two highest nights Pressure Pulses were 2,835 and 1,131 per night. After the drop, the two lowest Pressure Pulses were 5 and 30. IMHO, that's good!
So, there you go experts -- feel free to weigh in and let me know if I am crazy or not -- but, be gentle; I am very sensitive!
Sleep well!
