Lumis 100 ST BiPap stops before I'm done inhaling

[Fabrice01]

Years ago I was prescribed a CPAP S9 Escape with pressure 10 on the basis of a standard home sleep test whose result was AHI = 8 (mild OSA). CPAP therapy with pressure 10 yielded 0 benefit as it relates to my symptoms.

Recently, a WatchPAT test revealed AHI = 46 (severe apnea). I tried the machine again this time with pressure 12, intending to increasing from there. But even with EPR 3, I swallow air and get stomach ache. After some research I concluded I need a BiPAP machine, which can lower pressure way more during exhalation and apparently fixes air swallowing in most cases.

I received a Lumis 100 ST yesterday. Problem: with that machine, pressure drops before I'm done inhaling. I tried a trillion different combinations of settings - playing with Ti min, Ti max, Rise time, iBR on/off, etc. Nothing works: no matter the settings, pressure always drops before completion of inhalation. This 2021 thread sounds exactly like my issue:  Apnea Board Forum - CPAP | Sleep Apnea / Public Area / Main Apnea Board Forum v / Aircurve BiPap stops while inhaling (sorry, can't post URLs yet)

I concluded that that machine is not for me (and tbh I'm wondering who on earth is it for).

I have the opportunity to send it back and receive from the same source a Lumis 150 ST-A instead. My question is: can I be reasonably sure that I won't experience the same issue with that machine? I understand it has EasyBreathe (contrary to the Lumis 100 ST) and that that feature should fix my problem. But I prefer to get a second opinion from more knowledgeable people before committing to the exchange.

Earlier today I used my S9 again for comparison and it's 100% smooth - no pressure suddenly dropping while I'm still completing my inhalation. That's what I want from the Lumis 150 ST-A.

Any input on this would be welcome, thanks!

[SarcasticDave94]

A question, do you have some lung disease you're dealing with along with Apnea?

If the answer is yes, then your equivalent to the ST-A will work in the Lumis line. If it's just Apnea, you're going too high up the chain, passing over the VAuto.

[Fabrice01]

Just OSA as far as I know. Yes I should go for an AirCurve 10 S or an AirCurve 10 VAuto (both have Easy-Breathe) but the seller I'm dealing with doesn't seem to have any of those.

[SarcasticDave94]

The ResMed AirCurve VAuto will honestly be best. S will be OK, but I myself was supposed to try it recently. Note that S is a mode on VAuto.

S mode gives you static pressure, so single pressure exhale, single pressure inhale. I found it hard to use. VAuto was more comfortable.

Above this VAuto, you're going into overkill, and will not gain anything for the extra cost, at least how I'm viewing it. And you've already said the Lumis ST didn't seem to work.

[Sleeprider]

The Lumis ST should have a TiMax setting. You probably need to increase TiMax to a higher setting like 2.6 seconds. Try posting a chart from Oscar and let us know what your settings are.

[SarcasticDave94]

FWIW I think this Lumis ST will have almost the same settings available at VAuto and S. Just adds timed backup breath rate.

[StuartC]

Lumis machines do not have Easy-Breathe.  They only have Auto EPAP control (equivalent to VAuto mode) in iVAPS mode when max PS >= 8.  Otherwise they are fixed pressure only.  I don't think VAuto machines are sold in the UK.

The Lumis 150 ST-A is not necessary for you as an individual.  The only difference between that and the Lumis 150 ST is the addition of alarms that would be used in a care setting, plus the cost which is about 50% higher where I live.

It does sound like Ti Max needs to be longer.  As a guide, you could set it to 30 / RR where RR is either:

• Your backup rate in ST mode when iBR is off
  
• 2/3 of your Target Patient Rate in ST mode when iBR is on
  
• Your median respiratory rate
  
• At a stretch, your typical respiratory rate before you fall asleep and would otherwise feel the air being cut off, as you seem to be.  However, you may need to confirm that the increased Ti Max does not then cause problems once you are asleep.  
  

[Fabrice01]

Thank you guys. I really tried everything - I can only reduce the intensity of the issue but it nevers goes away. ST/ST-A is just good for me. Luckily I'll be able to have my Lumis 100 ST replaced with a different machine, probably a S9 VPAP S which *doeesss* have Easy-Breathe.

[StuartC]

One thought, have you tried increasing Rise Time?  I was once told that unless you have an obstructive lung condition (COPD), you can set it "for comfort".  I have mine set at the maximum of 900 ms.  No, a 900 ms rise time is possibly not as comfortable as Easy-Breathe, which takes about 1.5 s to increase from EPAP to IPAP when RR is about 15, but it made a big difference to me both in comfort and another statistic that is relevant to my therapy.

Note that you also need to set Ti Min to 1.0 s when setting Rise Time to 900 ms since Ti min should be longer than Rise Time.

[Fabrice01]

Yep I tried that too. No matter what I do the "forced" sensation never goes away - I can only make it milder but not enough for me to find it tolerable. I hope it will feel better with a non-ST BiPAP machine.