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[Treatment] Treating UARS with CPAP and bilevel - Printable Version

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RE: UARS and APAP - WillSleep - 10-23-2019

(10-23-2019, 04:43 PM)slowriter Wrote: This is interesting WillSleep!

It also seems to conflict with what Sleeprider was saying. Curious how he would respond.

Actually I am not sure Sleeprider are in any disagreement.  We both seem hopeful and positive that you might have found a new knob to turn that might help people who need it gain better Tidal Volume and Minute Ventilation.    


(10-23-2019, 04:43 PM)slowriter Wrote: This is interesting WillSleep!

So if you're right, how to bottomline this then?

Conclude that PS 6 is too high and EERS is not necessary for me?

E.g. what would you do tonight if you were me?

My initial impulse was to go back to the initial setting that reduced AHI to 0, which was min EPAP 6.2 and PS 5.2. At those settings, TV varied from 460-500, and MV was a bit over 7.

I have not yet thought it through enough to have expected that you would make any changes to your current plan.  If you are not feeling like your pulmonary system has been worked over when you wake up then short term use of higher volumes are not much of a threat.  Historically (now discredited as a norm), ER/Min Minute Vent at 10L/min for 28 days would not have caused anyone any concern so short term values are not too much of a threat  (However, if you really are pushing 9L/min this is a bad time to also get a really big volume-exploding leak that lasts for two hours.)

My inkling on the first next step is to figure out experiments to validate that TV and MV are in fact increased by EERS and if so, knowing the TV values published by all xPAPs are suspect, how much have they changed.

So we know we can trust what the ResMed is publishing or if we need to put some "English" or Skew on those numbers how much.  

Your a thinker and a good planner.  What do you think the next steps are?

WillSleep


RE: UARS and APAP - slowriter - 10-23-2019

Seems to me we need a wiki page that reflects consensus on this.

PS - I posted this while you were replying. Will respond separately.


RE: UARS and APAP - slowriter - 10-23-2019

(10-23-2019, 05:07 PM)WillSleep Wrote: My inkling on the first next step is to figure out experiments to validate that TV and MV are in fact increased by EERS and if so, knowing the TV values published by all xPAPs are suspect, how much have they changed.

...

Your a thinker and a good planner.  What do you think the next steps are?

WillSleep

I suspect that, while I was titrated at PS 6, which is always in the back of my mind, that I don't actually need that. The titration steps were in increments of 1, so it makes some sense that ideal could be something short of 6.

Also, when I did the study, I was using a different mask, that leaked more (though nothing terrible).

So then further, to your first point above, I think it might be valuable for other people who clearly need to increase their TV and MV to experiment with it, and that I may not be the right guinea pig!

Given what you wrote in your post above, it could be that my rough night was a consequence of a too high TV/MV, even if it wasn't obvious to me subjectively.

I mainly posted because I wanted to try to raise the profile of EERS more, given how cheap and simple it is to adapt a mask to provide the additional dead space. Perhaps more people will in time, and Sleeprider can expand that wiki page to incorporate that knowledge.

If you're right about the potential for too high numbers here, it does point out limits to EERS, and also a need for caution for those that do experiment with it. 

I guess ASV is for those cases where one needs really high PS, but EERS, while reducing or eliminating CAs, leads to over-ventilation?

WRT to us UARS folks, not sure what to conclude.

In sum, though, EERS seems worthy of much more thought, discussion and experimentation as one more tool in the toolbox.


RE: UARS and APAP - Gideon - 10-23-2019

The Wiki article needs to wait until you know this is correct and works.


RE: UARS and APAP - Sleeprider - 10-23-2019

(10-23-2019, 05:14 PM)slowriter Wrote: Seems to me we need a wiki page that reflects consensus on this.

PS - I posted this while you were replying. Will respond separately.

Anyone that wishes to volunteer as a wiki author should contact Supersleeper and let him know their interest.  We welcome the help and it's a good outlet for you geeks that like to write technical articles and explore strange new worlds of esoteric wiki code and sleep apnea problems.  Trust me, we can use the help to update hundreds of articles. There is a wealth of information on the forums that should become part of the Apnea Board wiki. Please see How to Become a Wiki Editor

With regard to my agreement or disagreement with Willsleep's theories on tidal volume or minute vent, I am somewhat agnostic.  There is a great deal of variation among individuals and I don't feel we can necessarily judge results as good or bad based on CPAP data and no other health background.  I disagree that minute vents in the 9.0 L/min range infers "Ventilator Induced Lung Injury (VILI)".  There are any number of reasons an individual will have minute vent out of range of "normal".  I have noticed very high tidal volumes among many of the ASV users.  My own Mv is influenced by a miss-spent youth running trails at high elevation. I have the lung capacity of a deep sea free-diver, but has been there since I was much younger, prior to CPAP or any possible lung injury. Anyway, a simple pulmonary function test with FEV1 and FEV2 measurements can detect lung function anomalies pretty quickly, and mine are normal.  Whether a high or low volume is good, bad or indifferent is something I try not to judge unless there are very clear connections to a problem. My comments in this thread were mainly an observation that EERS seemed to enable a higher Tv and Mv.


RE: UARS and APAP - WillSleep - 10-23-2019

(10-23-2019, 05:14 PM)slowriter Wrote: Seems to me we need a wiki page that reflects consensus on this.

PS - I posted this while you were replying. Will respond separately.


Hi Boujour,  

I Think he was asking for a Wiki page on proper Minute Vent & Tidal Volume. 

Do you know?  Does one exist now?

WillSleep


RE: UARS and APAP - WillSleep - 10-23-2019

(10-23-2019, 05:49 PM)Sleeprider Wrote: My own Mv is influenced by a miss-spent youth running trails at high elevation. I have the lung capacity of a deep sea free-diver, but has been there since I was much younger ..

I spent good part of my youth play sports and running around the Rockies at 6-12k feet but do not have a large Tidal Volume.  

Now I feel robbed.    Too-funny

WillSleep


RE: UARS and APAP - slowriter - 10-23-2019

(10-23-2019, 05:52 PM)WillSleep Wrote:
(10-23-2019, 05:14 PM)slowriter Wrote: Seems to me we need a wiki page that reflects consensus on this.

PS - I posted this while you were replying. Will respond separately.


Hi Boujour,  

I Think he was asking for a Wiki page on proper Minute Vent & Tidal Volume. 

Do you know?  Does one exist now?

Yes, a resource that would explain that part of the discussion here, and essentially reconcile what Will and SR have said, independent of the EERS stuff.

While I'm at it, at some point something that answers a question I asked earlier in this thread (and I've seen others ask), but still don't know the answer to: how to properly set Ti max and min based on the machine data.


RE: UARS and APAP - WillSleep - 10-23-2019

(10-23-2019, 05:32 PM)slowriter Wrote: Given what you wrote in your post above, it could be that my rough night was a consequence of a too high TV/MV, even if it wasn't obvious to me subjectively.
  

I for one am very glad you are pursuing this line of experiments, trying to replicate that peer reviewed study and his results.   I will come back to this in a minute in another post. 

  
First lets take about the safety of high volumes.  

I wont repeat anything above beyond if your not feeling pain, not hoarse, not feeling congestion in the lungs, or sort throat, no change in voice or ability to sing at the top of your lungs as normal, not notice any sign of secretion in the lungs or notice any reduced lung capacity when working out then short term at 9L/min might be low risk.  

There is probably a lot of over lap between the two column of doc counts below but collectively safe to say there are roughly 1000 docs on these topics at PubMed and the number of new docs has been increasing each year since 2013.
https://www.ncbi.nlm.nih.gov/pubmed/?term=VILI 

[attachment=16472]  

I am totally fine if I am standing completely alone with these views.   I am just making the info available hoping people will start to mull it through. I see highlighting this info as a Public Service contribution to forum.   I have to share what I have seen. It would be a complete lapse of integrity to not share the info with this great group.  

My view:  I think we as a community we need to calmly, methodically start to slowly add an understanding of Ventilator Induced Lung Injury (VILI) to our base of general understanding so we as each individual can better distinguish "having a hard time adjusting to PAP" from this hurts and is hard because the therapy as configured it is actually injuring me and I need to reset this approach with the Doc.  We need to learn when the pain is causing a permanent injury and we should stop and I believe the group should continue to methodically grow in our skills of learning how to ensure the xPAP-patient synchronicity key to preventing injury.  

I agree people blessed with larger or lower tidal volume should of course adjust the numbers to better fit reality.  Most of us do not know what our lung capacities are and "should" visit a Pulmonologist for testing to find out so we can tighten up the accuracy of the numbers we use.    Hopefully there may be an easier BioHacker solution to finding out without a trip to the Doc.  

////////

Slowriter,  I have no idea of your lung capacities, etc.  You need to personally decide what is right for you.   

I by no means want to be the boy who cried wolf ... and at the same time I believe it is important to err a little bit on the side of health and safety.  

I will just share what the Medical community and the U.S HHS agency has published.  

Everywhere I have seen the normal published range of MV for adults is 5-8L/min  Wiki, papers, tons of site..  online calculators like this  http://www.scymed.com/en/smnxpr/prrdv372.htm  (This site show 4L/min as the low but does not limit scope to adults.)  

HHS AHRQ has published and is pushing broad adoption of the ARDSNet detail I published above as core content in it's "AHRQ Safety Program for Mechanically Ventilated Patients."   
https://www.ahrq.gov/hai/tools/mvp/modules/technical/ltvv-intro-slides.html     

The same ARDSNet table for Predicted Body Weight I published above is part of the AHRQ saftey program content. 
[attachment=16473]

If you follow the higher normally recommended as temporary starting tidal volume of 8mL/Kg (620mL at 6' high) per breath that would land you at a recommended MV of 7.44L/min (TV of 620ml * RR of 12).  The 600mL/breath you showed by itself does not look so high, it is the 9L/min number that caught my eye. 
 
I thought I had somewhere seen the similar ARDSNet PBW chart published by ResMed so went to look for it.  I did not find it on Google or in any of the clinical guides, not even for the Stellar 150. 

Googling ResMed for their latest regarding PBW for TV calculation I surfaced this 2017 ResMed paper arguing to collapse the Male and Female chart into one model they argue is more accurate and better because it extends down to children.  You could also test yourself TV values against this proposed PBW replacement model but with only one other paper referencing this one the industry has not yet accepted ResMed's proposal.  

Predicted body weight relationships for protective ventilation - unisex proposals from pre-term through to adult.  https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5442651/  
It is proposed that the PBWuf + MBW model, which adopts the Devine PBW Female formula as the adult unisex prediction, be considered for use in protective ventilation. This model acknowledges current practice and offers clinical simplification, while providing lean body weight estimation down to pre-term infants. ... the MBW curve best reflects lean body weight for all body sizes and may therefore better estimate resting metabolic demand ...


The only article citing the latest ResMed article above included the text pasted in below.  I did not cherry pick this paper, it was just the only paper citing the ResMed article above and the only other paper I opened.   There are many papers on PubMed with similar content, and many of those go down to very low levels with explicit detail on the exact injuries taking place, how and why they are taking place.  

Note that the that the population being studied by this paper all participated in ICU treatment so these were not the healthiest patients one could have possibly studied. 

Evaluating Delivery of Low Tidal Volume Ventilation in Six ICUs Using Electronic Health Record Data.   https://www.ncbi.nlm.nih.gov/pubmed/30308549
SETTING: Six ICUs in a single hospital system.
PATIENTS:  Adult patients who received invasive mechanical ventilation more than 12 hours.
MEASUREMENTS AND MAIN RESULTS:  Tidal volumes were analyzed across 1,905 hospitalizations. Although mean tidal volume was 6.8 mL/kg predicted body weight, 40% of patients were exposed to tidal volumes greater than 8 mL/kg predicted body weight, with 11% for more than 24 hours. At a patient level, exposure to 24 total hours of tidal volumes greater than 8 mL/kg predicted body weight was associated with increased mortality...
CONCLUSIONS: Despite low mean tidal volume in the cohort, a significant percentage of patients were exposed to a prolonged duration of high tidal volumes which was correlated with higher mortality.

The only thing I am hoping you would draw from that high-level paper above is "Yes, OK, this is a topic I should be concerned about." Then just be aware risks exist and navigate your path and experiments to make sure you stay safe.    

Joyful material isn't it.  

Happy Wednesday.    

WillSleep


RE: UARS and APAP - WillSleep - 10-23-2019

(10-23-2019, 05:49 PM)Sleeprider Wrote:
(10-23-2019, 05:14 PM)slowriter Wrote: Seems to me we need a wiki page that reflects consensus on this.

PS - I posted this while you were replying. Will respond separately.

Anyone that wishes to volunteer as a wiki author should contact Supersleeper and let him know their interest.  We welcome the help and it's a good outlet for you geeks that like to write technical articles and explore strange new worlds of esoteric wiki code and sleep apnea problems.  Trust me, we can use the help to update hundreds of articles. There is a wealth of information on the forums that should become part of the Apnea Board wiki. Please see How to Become a Wiki Editor


If the forum leadership wants me to Write up a Wiki page on this topic I would be happy to do it. 

Something along the lines of 

The whole page strongly biasing to only referencing highly authoritative content and creating no truly new content.

Draft Contents: 

1) TLDR:  Why the Wiki page exists and what down to earth pragmatic results we hope people will take from the page. 

2) Injuries can occur to both the Cardiovascular and Pulmonary systems and a few sentence and i image intro to the Cardo<>Pulmonary system interactions.  

3) A sentence or two TLDR for each paper and then intro and URL to papers on each of the following:
  • Top Level overall Tutorial: A good on getting to the point fast VILI injury risk tutorial paper written by staff at a London Hospital.  
  • Link to a Paper/Article with a little more in-depth content on impacts to our Cardio system: Apnea arousals, PEEP/EPAP & PS fluctuations impact on our Cardiovascular Systems paper.
  • Link to a Paper/Article with a little more in-depth content on key components of and impacts to our pulmonary system.  

4) Now shifting to be very tactical, identifying hard takeaways and tools 
  • A few key ARDSNet published pages 
  • A few published pages from the "AHRQ Safety Program for Mechanically Ventilated Patients"
  • General How-to Tips and Actions recommended to forum members on specific actions to take avoid injury.  These will come from forum members, may already be recommendations commonly taking place and some may be new and hopefully become recommendations that start to appear commonly in the "please help me threads."      
 

All referenced links will be published at a medical journal, PubMed, Medical Institution (e.g. Mayo, John Hopkins), Research Gate, ARDSNet or a US Gov HHS site.

What do you guys think?

WillSleep