[Equipment] HELP - BIPAP-ST Restricting Inhalation/Exhalation Air Flow / Tidal Volume

[PAPPER101]

Re: HELP - BIPAP-ST Restricting Inhalation/Exhalation Air Flow / Tidal Volume

I just started (first night after) using a RESMED Air Curve 10 ST-A to treat for CA.

- I woke-up today with cramps in the stomach/diaphragm area and low-back pain (Kidney's?).
- I have 6.5 years experience using CPAP / BIPAP devices, and I am accustomed to dedicated (97-100%) use.

- I notice that the (ST-A) air-flow on a deeper inhalation breath gets restricted/limited at a certain point by the device.
- I notice that the (ST-A) air-flow on a deeper exhalation breath gets restricted/limited at a certain point by the device.
- I notice on occasion that the (ST-A) air-flow mid-inhalation breath gets restricted/limited/blocked at a certain point by the device.
- I notice on occasion that the (ST-A) air-flow mid-exhalation breath gets restricted/limited/blocked at a certain point by the device.
- I notice that the air-flow between the exhalation and inhalation breaths is more abrupt/jerky (a sharp cut-off in pressure).

This used rental device was set-up by a Vendor according to the new Prescription and matching comfort settings of my previous BIPAP-V-AUTO.

Are these air-flow/tidal volume respiration cycle restrictions caused by the BIPAP-ST Backup Breath Rate (12/min)?

Is this normal for the BIPAP-ST to restrict/limit the duration (or tidal volume?) of an inhalation/exhalation breath? (and just takes some getting used to?)

Are there specific device settings (i.e. IPAP / EPAP / Minute Ventilation) related to these air-flow / tidal volume limits?

Is any of this covered within an existing SAB Thread? (I tried to search before posting this Thread)

Thanks-kindly for any insights you may share!

[stevew168]

I think you would be better getting an AirCurve ASV than an ST-A to treat CAs. The latter has a air pressure that resembles a square wave, while the ASV air pressure change is much more natural. The abrupt change in air pressure with the ST and ST-A is a common complaint from users of that device. If you have additional respiratory issues, such as COPD, an iVAPS might be a better choice.

[PAPPER101]

HELP RECEIVED - Thanks-kindly for your insightful feedback!

I did ask my Sleep Specialist about ASV in light of the CA issue, but he wanted me to try the ST (first?) without any explanation (acting as if ASV is too risky).
- I don't see much of a price difference between these two devices (not that our wonderful "Health-Care" system will cover the cost of either device).
- BTW-1: Our Doctors in Canada don't take much time to review sleep data (just a cursory review of the device dashboard during short [5-7 min] consults - Cha-Ching...).
- BTW-2: In Ontario, our "Health-Insurance" plan (OHIP) only covers the monthly-rental of a used/refurb ST/ASV device, as if they don't see any merit in funding new devices for those with CA (who won't live long enough to justify the cost) (but they'll surly pressure/coerce/presume my consent and pay any price for assisted suicide ("MAID")).
- - As a result, I suspect that the availability/use of ASV Devices in Canada is limited.
- Seems that if I hadn't been printing out Reports using Oscar, with integrated Oximetry, showing 60s non-breathing (non-hyperventilation triggered) respiratory cycles, stacked end-to-end, my Dr. would not have ever acknowledged the CA issue.
- - - SHOUT-OUT to Team OSCAR for saving my life! - Q. Has anyone else reported that the availability and use of Oscar likely saved their lives? (no-way I'm the first!)
- - Even though "CA" (30/hr) was clearly listed as the dominant issue within my 2022 Polysomnography Report (What's up Doc?) (misdiagnosis?/underdiagnosed?/written-off?). 

Your point about the square wave could explain (for my mind) the jerky stops, blocks, tidal volume issues I am experiencing/describing using the ST-A.
- I am also noticing a shorter respiratory cycle (Ti = 1s) with the ST-A (I believe that this was longer using BIPAP-V-AUTO, and often I have 2.5s deep inhalations naturally).

Besides informing my Sleep Dr. that I am finding the respiratory rhythm/rate using the ST-A to be uncomfortable:
- I.e. Interrupted inhalations.
- I.e. Interrupted exhalations.
- I.e. Wrestling with the ST-A control of my natural respiratory rate/rhythm.
- I.e. Shorter/anxious respiratory cycles.
- I.e. Difficulty sleeping & poor sleep cycles.
- I.e. Fatigue during the day.

Is there anything else (experience or terminology wise) that a dedicated PAPPER like me might consider informing their Sleep Dr. to help put the benefits of using ASV into proper perspective for managing CA?

[stevew168]

Yes, OSCAR and my very excellent sleep doctor got me an ASV because Medicare after an audit declined to pay for my ASV, so my sleep doctor used my OSCAR overview to justify Medicare paying for my ASV with a different DME because it showed Cheyne-Stokes Respiration with my AirSense.

BTW, the ST-A has a fixed backup rate (adjustable) while the ASV adapts to your respiratory rate during the first 90 seconds after you turn it on. That really helps, especially when you sleep after having a few drinks. LOL!

[PAPPER101]

RE: * UPDATE * Central Apnea Syndrome - BIPAP ST-A vs BIPAP ASV

Further to my previous Posts and your excellent feedback APNEABOARD.

My Sleep Specialist was able to locate a used BIPAP ASV device (RESMED Air Curve 10) through my current DME Vendor for my temporary use/trial.

After a clinical data review and some Sleep Specialist's tweaks I am finding upon awakening that I am feeling better refreshed with fewer arousals and strange respiratory artifacts (using OSCAR to review device clinical data).

I performed an (unqualified) assessment of the issues I was having with the BIPAP ST-A (which was constantly interfering with my normal respiration) and I discovered the following:

My 99.5% Ti (inhalation breath interval) plus my 99.5% Te (exhalation breath interval), being my average Complete Respiratory Cycle was adding up to 7.35 seconds.
- The ST-A "Backup Breath" when set to a rate of 12BB/Min = 1 forced (by the ST-A Device) breath every 5 seconds (a discrepancy of 2.35 seconds). 
- The ST-A "Backup Breath" when set to a rate of 10BB/Min = 1 forced (by the ST-A Device) breath every 6 seconds (a discrepancy of 1.35 seconds).
- While an ST-A "Backup Breath" if set to a rate of 8.16BB/Min = 1 forced (by the ST-A Device) breath every 7.35 seconds (would have resulted in a discrepancy of 0.00 seconds).
 
* Incidentally, I am unaware if any of these PAP Devices measures the interval of time (i.e. lag/delay/suspension) in-between the inhalation and the exhalation breath cycles?
 
Q. Can any of you excellent PAPPERS please let me know if my logic could help explain the struggle (at least in part) that I was experiencing while using the ST-A Device?   

Overall I am finding that the MED-SYS here in Canada seems generally reluctant to diagnose Central Apnea Syndrome (CAS), and prescribe ASV Devices, perhaps this is due to the fact that the "Health Ministry" refuses to fund ASV Devices via our "wonderful" "Health Care" system? 

Also, it seems that getting medical referrals to Apnea conversant medical specialists (i.e. Cardiologists / Radiologists / Neurologists / etc.) to properly assess the potential scope of CAS (i.e. Q. are there any underlying/co-morbidities (cardiology / neuropathy) conditions associated with the CAS?) is an uphill & constant battle.

Many-thanks to the APNEABOARD for (being spot-on) helping me to move forward in the right direction (ST-A [HELL] to ASV [CALM]).

[SarcasticDave94]

Well the thing is the ST-A is a ventilator for lung disease not treating the Central Apnea. At least not in the same way as the ASV. This ASV was designed specifically for CA treatment. While the V in ASV means ventilator, it's not quite the same thing as the ventilator class of machines, whereas the ST-A is the beginning of that ventilator class in ResMed.

I would say the biggest struggle was being issued a very big sledge hammer of ST-A ventilator to treat CA while the specialized hammer ASV was neglected.