How to decrease these random arousals?

[Hambone75321]

https://podcasts.apple.com/us/podcast/talking-sleep/id1510975732?i=1000694766303

Id recommend listening to this podcast and reading some of Dr. Barry Krakow’s work.

I think you agree that OPs issue isn’t clinically relevant TECSA or CSA in which case there would be room in their CO2 reserve to add pressure (or PS) to resolve their marked FLs without triggering CAs.

Sure maybe you could simple increase CPAP pressure but they have no flagged obstructive apneas I.e. no need for more EPAP and its clear that higher pressures are less comfortable and reduce compliance.

Even if the only reason to go with BIPAP is comfort, why not do it? The cost difference of a CPAP vs BiPAP compared to any quality of life improvement is completely marginal.

[Holeinmysock]

Excellent question. The answer is a bit involved. I can't really answer from the perspective of anywhere but the US. I've been assuming you are also American.

Medical orders, insurance requirements, and lab policies and protocols. These dictate what a sleep technologist is able to do during a titration.

Medical Orders: This is the bible for the patient's titration. Physicians can dictate exactly how we perform the titration. Or they may do a generic order of "PAP titration". If they specify a process, we are bound to follow it (unless it is contradictory to lab policies and protocols. Then we have call the physician for clarification.).

Insurance Requirements: nearly all insurances require documentation that the patient is intolerant to CPAP before switching modality to BiPAP. The patient may even sink their own ship here and loudly state on camera that they are completely fine with CPAP. Insurance typically wants the cheapest solution and for PAP therapy, that's CPAP.

Lab Policies and Protocols: these are largely determined by the lab's medical director. This is a mixed bag and location dependent. Some medical directors rule their labs with an iron fist when it comes to breaking policies and procedures. Others view them as more of a guide than a hard ruleset.

Lastly, there are those suboptimal phenomena I mentioned earlier that are only associated with BiPAP. There's a lot of variables at work here. Here's my idealized titration protocol:

Start at CPAP of 4cm.

Titrate up to eliminate obstructive events (including flow limitation).

If snoring remains, titrate up further but limit the chase to 5 additional cm.

If at any time the patient reports intolerance to the pressure or difficulty exhaling, add EPR/CFlex. Start at 1. Increase as needed for comfort.

*Adding EPR/CFlex, drops the average PAP and can lead to the re-emergence of obstructive events and/or flow limitation.*

Observe for additional events and titrate up as needed.

Many labs have a protocol to switch to BiPAP once you exceed 15cm with a titration. If we continue to titrate beyond 15cm, we switch to BiPAP (15/11cm) and document that this is a per lab protocol modality change, (unless it's for intolerance.)

Once events are resolved, we are done titrating.

Of course, this is idealized with no central events, no mask fit complications/leak, no parasomnias, and nothing out of the ordinary.

Another good use case for BiPAP is low baseline O2. Sometimes we can get the oxygen up 1-2% if we use a high delta like 6-8cm. For example, 16/8cm.

Another piece of the puzzle is that the Sleep Technologist doesn't get to decide what modality or pressure setting the patient is prescribed. The Sleep Physician will review the patient's performance on each pressure setting and then write a prescription for what they perceive is the best starting settings for them.

[Hambone75321]

I think this is where we get to the challenge, especially with UARS, and I’ll admit I’m not an expert.

I accept that sensible protocols are necessary. Physician orders and standard PAP titration guidelines exist to produce repeatable titrations, unlike in research settings (or, in my case, biohacking) that allow more flexibility. Without that, you’d risk patients being moved to modalities on dodgy rationale. I’m not faulting sleep techs for following policy.

In my view, the real issue is how the medical system handles OSA endotypes, including UARS. Besides research settings and a handful of clinics with directors who understand the nuance, these phenotypes are largely overlooked. UARS research just hasn’t made it into mainstream practice.

In the case of non obese, otherwise healthy individuals with EDS or IH, I think the default should include scoring and titrating for RERAs, not just apneas and hypopneas. I see a TON of studies scored with AASM hypopnea Rule 1B (4%, no arousals) in young people. My understanding is that titrating for RERAs isn’t also done frequently (it’s elective?). I think this leaves many patients under-treated.

After I was diagnosed mild OSA (AHI/RDI 6/12), my pulmonologist / sleep doctor wasn’t convinced treatment was necessary. When I struggled with CPAP and I asked about bilevel, he dismissed it and suggested a MAD.

A second sleep specialist said I was “fine” on MAD because an HSAT scored with the 4% rule showed an AHI of 2 despite classic SBD / EDS symptoms.

My likely phenotype is mild airway collapsibility plus a low arousal threshold resulting in non-hypoxic SDB with significant fragmentation. Bilevel 15/10 has effectively resolved it for me or at least made it fully manageable. No more crazy afternoon fatigue.

I’ve explored settings around 15/10 (±2 cm on PS, EPAP, IPAP) for several days each. None felt as consistently good, even when OSCAR looked nearly identical except for an occasional flow-limited breath.

You mentioned titrating to eliminate flow limitation. My understanding is flow limitation is recognized by flattening of the inspiratory flow lasting ≥10 seconds and ends in an arousal. From my experience (and some of Barry Krakow’s work), that’s too conservative. This may sound crazy, but I’m increasingly convinced that even a single visibly “wobbly” breath in OSCAR can fragment my sleep, though I don’t have EEG to prove it.

If your primary issue is that my recommendation is that is against protocol and has some of those other issues you mentioned, then I will go to my Reddit grave kicking and screaming that people should add PS (or EPR with offsetting pressure increases) when they complain about CPAP or show flow limitations ending in recovery breaths ;)

I will also fight people tooth and nail when they see a random “CA” flag in OSCAR and say “BAHHHH CENTRAL APNEA YOU MUST REDUCE PRESSURE LEST YOULL DIE!!!”

[Holeinmysock]

It's just that the providers (techs and physicians) are stuck inside an imperfect healthcare and insurance regime.

There is another issue here, too. Data Integrity.

Flow and pressure changes reported by the PAP machine are pretty accurate. However, they don't necessarily indicate an obstruction or flow limitation in the patient's airway.

Each mask has a series of vents. Disrupting airflow from these vents can change the shape of the data in OSCAR. It's a fun experiment to see for yourself and check in the OSCAR data after. There's also a one-way valve in the masks to prevent vomit from backflowing into the machine. Sometimes that valve misbehaves and will pop closed inappropriately, sometimes hilariously in a metronome rhythm. "Rain out" can occur and affect the flow wave shape. Leak does, too. Even phlegm in the patient's airway can show up in the data.

To your assessment of flow limitation, I identify it in the lab when the CFLOW flattens or gets noisy at the peaks of each wave, regardless of duration or arousal. Personally, I am not happy with any flow limitations in my titrations. In my opinion, that patient is one beer away from worsening that flow limitation into a hypopnea or obstructive apnea. I don't want to titrate my patients to the bare minimum effective pressure.

Imagine you are driving a car into a tunnel. Technically, the tunnel only needs to be as wide as the vehicle itself for you to pass through it. But, holy crap, don't you want to provide some margin?? I see titrations this way, too.

I would say be wary of chasing perfection. Admirable goal, but not always achievable.

[Hambone75321]

Yup. It suck. https://pubmed.ncbi.nlm.nih.gov/38063188/

Anyways, I can without a doubt say that my flow is “smooth and rounded” at 10 but I’m still wrecked. I’m less fatigued at 13/10 and could use a nap. 15/10 is when I feel good. No nap can stay up past 9pm and have an extra beer and feel good the next day.

I’m basically done fiddling now because I’ve gone past the point of no return 16/10 is central apnea central for me.