Where do I begin? [AirCurve 10 ST to Aircurve 10 ASV ]

[Bird Brain]

Please forgive me if I do not post this right as I am not a computer wiz!

I am a 70-year-old male. Height, 71”, weight 267 lbs. I have been a CPAP user for 27 yrs. For the last year or so, I have not been sleeping well. Went to a sleep Doc and let him know about my nights rest not being very good. I sometimes would wake with shallow breathing and not being rested in mornings. He recommended I go through another Sleep Evaluation since my last was in 1994. After obtaining the results of the Sleep Evaluation, his plan recommendations are as follows, "Patient was having breakthrough snoring and centrals and looked best on BIPAP with back-up rate. Will start on BIPAP ST with backup rate of 15, IPAP 21, EPAP 16 and re-assess."

After a 6 week wait, I finally received a ResMed BIPAP ST machine with the following settings.
Mode: ST
IPAP: 21.0
EPAP: 16.0
Resp Rate: 15.0
Ti Max: 2.0
Ti Min: 0.3
Rise Time: Min
Trigger: Med
Cycle: Med
Mask: ResMed Mirage Quattro
Ramp Time: Off
Climate Ctrl: Auto
Temp Tube: 80 F
Humidity Level: 4
 
The first night I was bombarded with constant IPAP/EPAP pressures. Felt like pressure oscillations could not get a relaxed breath or sleep. I have been unsuccessful with his prescription. 

To be able to get some sleep, I changed the settings as follows.
Mode: ST
IPAP: 16.0
EPAP: 14.0
Resp Rate: 8.0
Ti Max: 4.0
Ti Min: 0.3
Rise Time: Min
Trigger: Med
Cycle: Med
Mask: ResMed Mirage Quattro
Ramp Time: Off
Climate Ctrl: Auto
Temp Tube: 80 F
Humidity Level: 4

If I try to raise the Resp Rate above 8.0 it feels like the machine wants me to exhale before I finish inhaling or it wants me to inhale before I am finished exhaling so it is left on 8.0
 
I am attaching data from the sleep evaluation data and Oscar data with the seccond set of settings.

[SarcasticDave94]

Welcome to the Apnea Board,

From what you've described, Central Apnea and getting a machine with backup rate, in this case the ST. Your doctor only partially helped, but chose the wrong machine. ST is the older answer to Centrals, but it's best use scenario is respiratory disease not Centrals, at least not any longer is it the right answer to CA. There's a newer model called ASV that will be much better for you than ST. The ASV was designed specifically to combat Central Apnea.

I would do a few things, request the full diagnostic test results from this recent test. Then I would also request a doc visit to present your symptom and complaint list that includes ST isn't helping as much as you desire. Request that doc orders a replacement, swapping ST for ASV, specifically the ResMed AirCurve 10 ASV.

[Sleeprider]

When using the ST machine it is usually appropriate and recommended to set the respiration backup rate at 3 BPM less than your normal respiration rate. In your case a backup rate of 12 BPM looks like a good starting place. A lower backup rate can be titrated based on comfort, however I think you may have gone a bit to far with a rate of 8 bpm. I would like to see you trial some backup rated between 10 and 12 bpm.

You reduced your pressures from 21/16 (PS 5) to 16/14 (PS 2). EPAP min should be used to prevent obstructive apnea and hypopnea, and it is PS that provides the assistance in getting more tidal volume (deeper breath) and to stimulate breathing during central apnea. Again, you have reduce the PS too far. I agree you should use lower pressure, mainly because your sleep study shows you AHI does not improve with higher pressure or with bilevel pressure. With CPAP pressure of 10 to 14 you experienced hypopnea events that were most likely central in nature. At 15 cm central apnea began to appear and was present through all the higher pressures and bilevel pressure. As a result, I strongly disagree with the interpretation of your doctor, and will discuss it in more detail below. I think you can cut your EPAP pressure to 8.0 and use an IPAP pressure of 12.0 for PS 4.0. I'd like to see you try these lower pressures and higher pressure support with a backup rate you find tolerable between 10 and 12 BPM. Post those results and we can decide where things need to go.

Your sleep study shows no obstructive apnea, but hypopnea and centrals are present at all pressures tried. In fact your prescribed pressure was perhaps worse than any of the lower CPAP pressures tried. I would call this titration a failure because it did not evaluate ASV which would have stopped all events with much lower pressure. In fact, most ASV users achieve near zero AHI with an EPAP pressure range of 5.0 to 7.0 and pressure support from 3.0 to 12.0. Simply put, as Dave suggested above the ST is not the right machine for you for either comfort or efficacy. The ST is a relatively dumb machine with fixed pressure, while the Adaptive Servo Ventilator (ASV) provides therapy for both obstructive and central events by changing pressure on a breath by breath basis. This makes it comfortable and effective in treating all types of events. Assuming your discomfort continues, you should ask for a titration test with ASV, and that will simply prove what we are saying here, that the ST machine is a poor choice for your conditions.

[Bird Brain]

Thanks for the responses. I have made the changes as Sleeprider suggested.

Mode: ST
IPAP: 12.0
EPAP: 8.0
Resp Rate: 12.0
Ti Max: 3.3
Ti Min: 0.3
Rise Time: Min
Trigger: Med
Cycle: Med
Mask: ResMed Mirage Quattro
Ramp Time: Off
Climate Ctrl: Auto
Temp Tube: 80 F
Humidity Level: 4

Initially had difficulty with the IPAP/EPAP cycle. Machine was giving IPAP pressure when I was still exhaling and EPAP pressure while I was still inhaling, but stayed with it until I drifted off to sleep. I am including two graphs of the night’s session.

[SarcasticDave94]

It appears the clusters of Hypopnea events are a Positional Apnea issue. This kind of Positional issue isn't the same as the sleep study of side, back, stomach body position. This is a bending of your neck that kinks the airway much like the kinked garden hose has reduced water flow.

There's 2 main ways to fix this, reducing the pillow stack to a single thin pillow, or consider the soft cervical collar to support your neck to minimize the kinking.

Doctors will not recognize this as an issue or the resultant remedy. Docs will likely say turn up the pressure and it will not work. There's evidence of others combating this and showing a before and after OSCAR charts that confirm it.

[Sleeprider]

I am going to disagree with Dave on this one. I think you have mainly central apnea, and the clusters are not unusual for that. Your results at 16/14 were considerably better than 12/8, and that may be a function of the higher pressure or lower pressure support. Your respiration rate was 14 bpm so the backup may have been too high at 12 bpm, and my be better at 10-11 bpm. I think we should reduce the pressure support and try 12/10 at backup rate 10 bpm. We may end up moving back to your settings from 10/28, but we can learn from trying some alternative pressures.

You need and should have ASV.

[SarcasticDave94]

I had forgotten about the likeliness of Central Hypopnea, so these suggested actions make sense.

[Bird Brain]

Made changes.

Mode: ST
IPAP: 12.0
EPAP: 10.0
Resp Rate: 10.0
Ti Max: 4.0
Ti Min: 0.3
Rise Time: Min
Trigger: Med
Cycle: Med
Mask: ResMed Mirage Quattro
Ramp Time: Off
Climate Ctrl: Auto
Temp Tube: 80 F
Humidity Level: 4

Able to drift off to sleep without fighting IPAP/EPAP/Resp Rate pressures. Wife said she noticed I was snoring a little thru the night. Woke up as usual, not refreshed, headache, and brain fog.

[quiescence at last]

I can't remember if there is data on how often the patient triggered breath occurs, but seems like you only got to the 10 per minute about 5 times, and when you did, I am guessing the machine triggers your breaths, and a fairly jittery flow and minute ventilation occur. One such occurrence is at about 06:37 thru 06:49. You seem to have awakened about 06:40 based on the TV chart.

Your snoring seems not to have registered at all.

QAL

[Sleeprider]

Better results were still your first chart posted at 16/14. Additional sessions at that setting should show if this improvement is consistent.