Breathing pattern identification, Flow limitations and posture

[Jay51]

Thank you for those posts SingleH.  In regards to his neck hyperextension, I did not realize that it was that severe.  Thank you for the drawing.  That is way too much hyperextension and has to be kinking his airway.  My airway at night with my large collars looks like the 1st image, but maybe tilted back 5 to 10 more degrees.  The level of hyperextension your father has is incredible.  Hopefully your idea about his pillow and the way you plan on modifying it will keep him from getting into this extreme hyperextension.

You can try your basic finger spo2 monitor 1st.  Your choice if you want to get another one.  Wellue and Contec are both compatable with OSCAR I think.  Some other brands are also.  It is in the wiki here the brands that are compatible.

[SingleH]

Hi Jay51,

Just to be clear that is not his normal sleeping position, but on rare occasions if he is sitting and falls asleep or in bed he sometimes somehow ends up in this kind of hyperextended position with his head fallen back position. I think he needs a shaped pillow that fills the larger than normal  space behind his neck when laying down and then tilting his head forward a little to eliminate any kink.

Is the Weellue and Contec standalone devices and the data imported into Oscar separately or does it need to be physically connected in some way to the Resmed machine. The unit he has is not the type you can leave on, its just the little cheap £10 item that you clip on the end of your finger for 10 seconds to take a one off reading. It is not recording anything.

[SingleH]

What I suggest you do when you get the machine is start out in ST mode.  iVAPS (without AutoEPAP) is simply ST mode with the added feature of variable PS to achieve a target volume.  So start "simple".  Unless SleepRoder or others have better suggestions:

• Set the EPAP that you need based on the current pressure and EPR setting.  13 seems fine for the pressure and did I see EPR of 2?  EPAP of 11 in that case.  Or 10 if EPR was set at 3 and you did not experience OAs then,
  
• Set IPAP to 4 above EPAP.  If EPR of 3 was not enough, you may was well start with PS = 4 and work up as necessary
  
• You have two choices for backup rate.  Either turn intelligent backup rate off and set the rate to 10.  Otherwise turn intelligent backup rate on and set target patient rate (TPR) to 12.  Then intelligent backup rate will allow RR to drop to 8 (2/3 of TPR) before intervening, but then it will drive the RR up to 12 and continue at that rate until spontaneous RR is detected at a rate higher than 12.  The important thing to know about intelligent backup rate is that it is used in iVAPS mode.  So if you intend switching to iVAPS, get used to it in ST mode first.
  
• Set Ti max to 2.5 seconds for RR of 12.  Otherwise maybe as long as 3 seconds?
  
• Set Ti min to 1 second, as SleepRider previously suggested
  
• SleepRider, what Rise Time should be set?  I have been told it needs to be short for obstructive conditions and may be longer otherwise.  However, I get the impression you are suggesting a rapid rise to apply IPAP as quickly as possible and hold it for the duration of Ti min.  If so, leave Rise Time at "Min"? 
  
• And also for Trigger and Cycle?  SleepRider, I get the impression that you would suggest a setting different to "Med", for Trigger at least.  Is that right?
  

By starting in ST mode, one of two things is likely.

1. You will work out settings that are effective without needing to use iVAPS.  That would be a great outcome.
   
2. You will work out settings and determine typical minute vent / tidal volume that are a good basis for setting initial iVAPS settings.  It is certainly better to do that than to switch to iVAPS without good ideas of settings.
   

Hi Stuart,

I am setting up the machine now, as you mentioned to keep it simple and Sleeprider suggested the same and to use S mode I am starting out on that and entering the details as mentioned by Sleeprider and yourself.

I was a bit confused about the IPAP and EPAP comments.

EPAP - I was hoping to set a lower pressure than 13 as whilst his optimum settings (that he can tolerate and without mask leaks) is 13.0 to 17.0(no EPR) he needs the sensawake (F&P setting) set to 11 for pressure when he is awake. Can the EPAP be set to a larger gap of 4 below IPAP?
IPAP - What Pressure should I start with if I set a lower EPAP. At 13-17 on APAP he regularly gets below 1 AHI, on CPAP fixed pressure of 14, his AHI's are around 2.5, but the pressure of 14 tends to make him cough the day after as I think he struggles exhaling against it.
Ti Max - As he has a fairly shallow short inhalation and exhalation period, does this setting try to extend the overall breathing cycle. I presume if the lungs physically cant inhale or exhale any longer, is there a point at which there is no sense in extending this duration any further?

Apologies if I am misunderstanding anything on how things should be set.

There are the other settings I have applied


Ti Min 0.8 
Rise time 500ms 
Trigger High
Sensitivity Low


One other point is it normal for the Lumis 150 to make a sort wailing noise during the Inhalation phase?

[StuartC]

From what I saw, min pressure was 13 with EPR of 2 or 3.  EPAP = pressure - EPR, so EPAP was 10 or 11.  Pick one of those.  Since EPR of 3 was presumably not enough and the point of getting a BiLevel is to use more PS, set IPAP to be 4 higher than what you set for EPAP.  See how that goes before increasing further.

Ti Max is a limit, not a target.  It will cause pressure to cycle (change from IPAP to EPAP) after the time specified by Ti max if it has not happened spontaneously before.

[Sleeprider]

I'll post the standard VPAP-S protocol for reference.  The EPAP pressure needs to be set high enough to prevent obstructive apnea.  I have not see an OA on any charts up to now, so I suspect it is quite a bit lower than his current EPAP. I'll defer to your experience and ability to investigate where OA tends to onset due to lack of airway positive air pressure stent.  IPAP or pressure support (EPAP + PS = IPAP) needs to be sufficient to overcome flow limits and hypopnea.  The titration protocol starts at 4 cm and goes up based on observation.  We all expect that PS will be more than 4 cm, but it does not hurt to simply make the observations and respond to them as opposed to guess and end up with discomfort or over-titrated.   I do recommend a methodical approach to this procedure.  We have discussed a number of fine-tuning tips on TiMin, Rise Time etc, but the pressure titration is basic.  I agree with the use of a longer TiMn of 0.8 and suggested a rise time of 500 (.5 seconds).  As you know, your dad spontaneously triggers inspiration rather easily, so low trigger sensitivity to initiate IPAP is optional, but may become needed if we observe CA events or a latency in triggering IPAP.  Our objective is to make therapy comfortable, smooth-out the inspiratory fluctuations and maintain a healthy respiratory volume and SpO2.  We won't know the next step until we take the first.  That summarizes my current thoughts at this time. I'm sure they will evolve.

[SingleH]

Yes there were a few days where I tested EPR on level 2 and 3 but it didnt help possbly due to the machine applying EPR on his abnormal mid inhalation "exhalations" perhaps? 95% of his time he is just on 13-17 with EPR and Senseawake set to 11.

So I have set the following:

IPAP 14
EPAP 10
Ti Max 2.5s
Ti Min 0.8
Rise 500ms
Trigger High
Cycle Low
Climate control: Auto
Ramp EPAP: 3.0

Will let you know how it goes.

[Jay51]

Here is a list of OSCAR compatible oximeters.   http://www.apneaboard.com/wiki/index.php...e_oximetry   Just click on the oximeters link.  You don't have to attach the oximeter to the machine.  After your father uses oximetry during the night, just import that data into your laptop or desktop via (usb probably).  Then when you open OSCAR, it will have details in how to import the oximetry data into OSCAR and sync it all together on one timeline and date.  

[SingleH]

Hi Sleeprider,

I was hoping I wouldn't be replying so soon, but I am at my fathers house and had him using the machine for 20 mins.

I used the settings above and I dont know what was going on, the machine seemed to be really struggling as was by fathers breathing. On each inhalation the machine was making a laboured noises pitching up and down mid inhalation.
When I used the machine it made a linear noise increasing and decreasing in time with my inhalations. Its somewhat irritating given his F&P is almost silent.

I started the machine on a 5 min ramp, but pretty soon my dads breathing was all over the place and nothing like when he was on his CPAP. I made a few small adjustments as it didnt seem to be initating a breath at some point. So I set the trigger to high sensitivity. After about ten mins I could see it still wasnt working and reduced the TiMax to 1.5. There were also periods where he just didnt take a breath early on and then he did the same but I think they were apneas but not sure. I enabled the ST mode shortly and put the RR settings from Stuart and "I think" between those two adjustments one of them made a difference and things seemed to look a little better. I stopped it after 20 mins and uploaded the info in to Oscar.

As you can see there is lots of weird stuff going on and there is one screenshot where things look a little better. I noticed lots of changes in tidal volumes from 500 to 1200. 

When it normalised for a brief period it dropped to 500 tidal volume.

[SingleH]

[attachment=55036][attachment=55035][attachment=55034]

[SingleH]

[attachment=55037][attachment=55038]
Around this point I made some changes to the TiMax and reduced it from 2.5 to 1.5 and then enabled ST mode
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