Newbie needs help w/ Respironics S/T

These suggestions are offered based on the info you provided me & on the basis you are seeking to improve your therapy. If an RT already has looked at your data and gave you the #s you set the machine to then his advice should overide mine but I would be very very surprised if an RT would set you up the way this machine currently is. Your average apnea count for the night of 163, is 'over the top'. It is most likely being caused by 1) epap set far too low, 2) ipap set too high, 3) gap between too high.

So, having looked at your data, I agree with Rested Gal - you need to raise your epap - start by raising it to 9 one night then lets see the AHI count for that night to compare but I suspect we will have you up to 10 CMs epap the night after. Another suggestion is to lower your ipap to 14 as well.

Also (as Rested Gal already covered) set your BPM to a lower number (8 BPM will be ok), if you haven't already lowered it.

I have to say that the settings on this machine are odd !. Did you get advised by your RT ?.

Cheers DSM

DSM, the settings prescribed by my doctor, following the overnight test, were 16 IPAP, 8 EPAP, 10BPM for the S/T and 15 IPAP, 8 EPAP for my Bipap Plus (for travel). Doc said these settings were the best settings they could come up with in the overnight test that would allow to sleep on my back (which I could not do with my prior settings). The R/Ts at my DME are worthless at giving advice or helping interpret Encore reports. They say I have to see my Doc for any advice.

I lowered my BPM to 8 last night and the Encore report shows 94% patient triggered breaths and 126 average apnea count. This weekend I will take your and Rested Gal's advice and raise the EPAP to 9, then 10, leaving the IPAP at 16 and the BP at 8, and see if the apnea count goes down. Depending on how that goes, I may try lowering the IPAP from 16 to 15 and 14. I will use my oximeter to monitor any oxygen saturation levels. Like I said previously, I will also turn off the timed backup rate one night to see what happens! Like Rested Gal suggested, maybe I don't need a backup rate machine

I think I'm making good progress in my quest to tweak my settings.

Thanks for your insight.

Someone else may have suggested lowering the IPAP, but that's not what I'd do. Raising the EPAP, yes...but lowering the IPAP from its current setting of 16, I wouldn't.

rested gal wrote:Someone else may have suggested lowering the IPAP, but that's not what I'd do. Raising the EPAP, yes...but lowering the IPAP from its current setting of 16, I wouldn't.

RG, Yes certainly not until epap has been raised and trialled. But a gap of even 6 (if 10/16) suggests the sleeper will have some difficulty getting sound sleep.
However, that large gap could be ameliorated by pushing out risetime to 5 or 6. Balancing one against the other (gap vs risetime).

Cheers

DSM (someone else )

dsm wrote: But a gap of even 6 (if 10/16) suggests the sleeper will have some difficulty getting sound sleep.
However, that large gap could be ameliorated by pushing out risetime to 5 or 6. Balancing one against the other (gap vs risetime).

Doug, just some clarification please. I'm not at all nit picking. However, I am trying to understand the proper context of your statement.

Is the above suggestion that a central apnea patient might fare better by pushing rise time out to 5 or 6 common-sense medical reasoning on your part? Or is that suggestion part of central-apnea treatment protocol that you happened across somewhere in medical or manufacturer literature?

dsm wrote:But a gap of even 6 (if 10/16) suggests the sleeper will have some difficulty getting sound sleep.

I wouldn't make that assumption.

rested gal wrote:

dsm wrote:But a gap of even 6 (if 10/16) suggests the sleeper will have some difficulty getting sound sleep.

I wouldn't make that assumption.

It absolutely depends on etiology and even pathology. A PS gap of 6 or higher is known to be absolutely necessary for some patients to get sound sleep.

rested gal wrote:

dsm wrote:But a gap of even 6 (if 10/16) ***suggests*** the sleeper will have some difficulty getting sound sleep.

I wouldn't make that assumption.

Assumption ? -

D

-SWS wrote:

dsm wrote: But a gap of even 6 (if 10/16) suggests the sleeper will have some difficulty getting sound sleep.
However, that large gap could be ameliorated by pushing out risetime to 5 or 6. Balancing one against the other (gap vs risetime).

Doug, just some clarification please. I'm not at all nit picking. However, I am trying to understand the proper context of your statement.

Is the above suggestion that a central apnea patient might fare better by pushing rise time out to 5 or 6 common-sense medical reasoning on your part? Or is that suggestion part of central-apnea treatment protocol that you happened across somewhere in medical or manufacturer literature?

SWS Context (I hope this is not another argumentative merry-go-round - 1 per week is more than I can handle )

I was commenting on RG's post - and that the epap-ipap gap can be balanced off against risetime. There was no mention of someone with centrals.

If we are to talk about a patient with Centrals see my other posts on this issue where I say that a lab is the best place to get the gap & risetime tuned to the centrals the person is exhibiting.

DSM

#2 - a kind suggestion, why don't we start a thread to discuss the effect of epap-ipap gap on patients - those with just osa & then those with CA - I have asked you for thoughts on this issue before but we didn't follow through. I think it would make a good learning topic. I am sure you have a lot of insights to contribute & as a mere mortal I would be grateful for the opportunity to learn.

Cheers Doug

SWS, welcome to the my thread

First let me say that I am very comfortable sleeping with my prescribed IPAP 16, EPAP 8. I know from past experimentation that I cannot tolerate and EPAP of more than 10-11. Higher than that and I feel like I can't exhale, a very uncomfortable feeling to say the least. I'm comfortable with my IPAP of 16. Less than that and I can't sleep on my back without OSA episodes and without snoring.

While everyone seems to think my doctor / clinic don't know what they're doing, I just want to say that I don't think either is incompetent. While prefer not to post the doctor's name, I can say that it is the Mayo Clinic that conducted my overnight tests, and my doctor is a very senior doctor there.

Having said that, the reason I am trying to tweak my settings is so I can get my "average patient triggered breaths" into the high 90's, to see a reduction in the "average apnea count", to raise my SPO2 levels into the mid to high 90s, to feel rested when I wake and to eliminate as much as possible my daytime sleepiness.

Last night I raised EPAP to 9, leaving IPAP at 16 and BPM at 8. No major difference from the previous night at 16-9-8BPM. SPO2 levels remained the same at an average of 95%. Tonight I will again raise EPAP one notch to 10, and see what happens. I may try 11 the next night, but no more after that.

Question: On my S/T, I can adjust the Rise Time (from 1 to 6), and I understand what that is (I'm set to 2), but I don't understand what the Insp Time setting does or where I should set it. Is it how long in seconds the machine blows in (IPAP)? Right now it's set to 1.5Sec but can be set between .5 and 3.0. How will adjusting this setting benefit me?

Rise time is a comfort setting only. You should increase your Rise Time from your current setting to 3 (minimum). Inspiration Time should also be considered a comfort setting. Your Inspiration Time of 1.5 is in all likelihood too short. Especially with your current Backup Rate. You should increase your inspiration Time to 1.8 (minimum). Generally speaking, as you increase the Inspiration Time, you will find it more comfortable to increase the Rise Time. Your BPM should be set 2-3 BPM less than your resting (awake) BPM.

Banned

sleepy55 wrote:I don't understand what the Insp Time setting does or where I should set it. Is it how long in seconds the machine blows in (IPAP)?

I may be wrong, but I think that setting governs how long (in seconds) the machine is allowed to blow the IPAP, while you are actually inhaling. I don't think it means the machine will continue blowing the IPAP pressure for that amount of time IF you happen to start to exhale before the Insp Time has run out. The machine will switch to EPAP when you start to exhale.

sleepy55 wrote: Right now it's set to 1.5Sec but can be set between .5 and 3.0. How will adjusting this setting benefit me?

I don't know how the various times for that would benefit you, other than if you normally inhale for longer than 1.55 seconds, setting it higher would keep the machine from feeling like it cuts off an inhalation when the time runs out and the machine switches down to the lower EPAP.

Settings like Rise Time and Inspiration Time can be considered "comfort" settings for some people, BUT... those particular settings can also be essential crucial parts of prescribed treatment for other people. Best to ask your doctor if there is a specific reason to leave Rise Time and Inspiration Time as they are, or if it's ok to adjust those for comfort in your case.

I wouldn't raise anything until you KNOW what you are raising and what for.

Refer to the basics for bilevel therapy, these machines are no different;

IPAP handles Hypopnea and vibratory snore
EPAP handles Apnea and vibratory snore
CPAP handles both collectively.

IF apnea count is high, you increase EPAP,
IF Hypopnea count is high, you increase IPAP,
IF Vibratory Snore exists you may increase both,
IF you want to increase tidal volume you increase Pressure Support,

Here is what AVAPS guide says for S/T mode:

1. Set the target tidal volume, either to 110% of the displayed patient
tidal volume when ventilated on S/T mode or to 8 ml/kg of ideal weight.
Adjust depending on patient tolerance and clinical outcomes.
Target Vte may be set from 200 ml to 1500 ml.

Target Vte Chart (sorry it lost formatting, assumes ideal weigh, height more important, 59"=420ml, 75"=660ml etc.):

HEIGHT 59" 61" 63" 65" 67" 69" 71" 73" 75"
IDEAL
52.0 Kg 55.5 Kg 59.0 Kg 62.5 Kg 66.5 Kg 70.5 Kg 74.5 Kg 78.5 Kg 83.0 Kg
WEIGHT
VTE IF
420 ml 440 ml 470 ml 500 ml 530 ml 560 ml 600 ml 630 ml 660 ml
8 ML/KG

2. Set IPAP limit.
-IPAP max = 25 to 30 cm H2O depending on patient pathology
-IPAP min = EPAP + 4 cm H2O

3. Set respiratory rate 2-3 BPM below resting respiratory rate.

4. Set inspiratory time for the controlled breaths.
-Set Ti between 25% and 33% for obstructive patients.
-Set Ti between 33% and 50% for restrictive patients.

5. Adjust rise time to the patient’s comfort.
-Obstructive patients prefer short rise times from 1 to 4 (100 ms to 400 ms).
-Restrictive patients prefer long rise times from 3 to 6 (300 ms to 600 ms).

Nothing in these suggested settings is intended to supercede established medical protocols.

-SWS wrote:

rested gal wrote:

dsm wrote:But a gap of even 6 (if 10/16) suggests the sleeper will have some difficulty getting sound sleep.

I wouldn't make that assumption.

It absolutely depends on etiology and even pathology. A PS gap of 6 or higher is known to be absolutely necessary for some patients to get sound sleep.

or for that UARS SMUARS !!

@Doug- Sorry, my friend!!! The Respironics S/T title of this thread threw me off! I instantly thought this thread had to do with central sleep apnea because of the S/T machine.

@Banned- I agree that rise time is a comfort feature for obstructive and restrictive disorders. However, for central apneas, I am under the impression that elongated rise time can cause serious problems with short inspiratory times.

@Sleepy55 & Snoredog- Mayo Clinic is usually on the leading edge of consensus changes in sleep medicine. And one of those consensus changes in recent years is that higher gaps between EPAP and IPAP are now more routinely employed:

This year's AASM PAP titration clinical guideline wrote: 4.3.1.6 The recommended minimum IPAP-EPAP differential is 4 cm H2O and the maximum IPAP-EPAP differential is 10 cm H2O (Consensus).

Notice 3 cm isn't even in the picture anymore? And notice 10 cm is now part of the recommended range? I was surprised when I first read that.