Resmed Climateline Vs Oxy Hose

[Akeyla]

Simple question I beilieve.

I've been experiementing with different masks and different hoses to see how it effects things.  Currently I'm using an AirCurve ASV in ASVAuto Mode.  I'm comparing two types of hoses, the ClimateLine hose (15mm), and the ClimmateLine Oxy hose (19mm).  When I plug them into the machine they both generate the same message, "Climateline Air Connected".  Since both are being reported on-screen as the same thing when I plug them in, does the system know that the Oxy hose is larger diameter and must adjust its settings as such?  Or does it expect that if you're using that hose you're also piping O2 into the nipple which will increase pressures. I'll note that when using an N20 mask with each hose (despite it funnling down to the much more slim, short attachment hose) that the pressure feels less using the larger oxy hose.

I had heard something to the extent "Larger hoses good" so I tried it and ended up with the impression that larger hose resulted in less pressure on me not keeping the ol wind pipes open.

Anyways, thanks, please to meet you all.  Been on the PAP of a few types for several months and love it.  Don't want to confuse this post with all those details though.

[srlevine1]

The device's sensors algorithmically compensate for hose size factors to deliver adequate therapy pressure. However, unless you are using supplemental oxygen and require an "oxy" hose, it is a waste of resources. Remember, you need to set the tube type to slim or standard; the climateline sets itself. And, mask type to deal with leak reporting. 

According to ResMed...

What types of CPAP tubes are available?

Some of the main tubing options include:

Heated CPAP Tubes: Heated tubes should only be attached if you’re planning on using a humidifier. When plugged into a machine, heated tubes help to vary warm air from the humidifier into your mask, and the warmth of the tube ensures that the heated air doesn’t cool off while it’s transported through the hose.

Standard CPAP Tubes: Regular sized CPAP sleep tubes measure 22m in diameter and are suited to CPAP systems that do not contain humidifiers.

Slim CPAP Tubes: Slimmer options such as 15mm tubes or ResMed SlimLine tubing. Many patients prefer a thinner tube because it is lighter and more responsive to movements throughout the night. A reduction in mask drag makes it easier for you to move naturally and comfortably in your sleep.

OXY HEATED TUBING: If you require additional oxygen through oxygen therapy alongside CPAP, oxy heated tubing may be the answer. 

The ClimateLineAir oxy heated tubing is a variation that has a supplemental oxygen connector for those on oxygen therapy. Therefore, as well as delivering the additional oxygen required, the tubing also maintains a consistent temperature to the warm, moistened air delivered from the PAP machine.

If I remember correctly, the larger hoses were used for older, less sophisticated CPAP machines that benefited from tubing with a larger inner diameter to estimate and control the air pressure at the mask. In non-compensated systems, one would expect greater pressure and reduced flows from the smaller-diameter hose--but since the device is compensated, the point is moot. 

Best.

[ArcherNeedsSleep]

I just experienced the size issue with the oxy heated hose, too.  Long story short, I set up to use my new O2 concentrator for the first time and installed the oxy hose.  But, after ~30 minutes the concentrator threw a service error and I had to turn it off and cap the hose intake valve and use it without supplemental oxygen.  
(Turns out the concentrator is defective, and the new one is on the way)

Anyway, I noticed right away that the Aircurve machine wasn't behaving correctly, but I was too tired to investigate until this morning.  It appears that, although the machine auto-senses the heated tube, it doesn't seem to understand the larger tube size of the oxy.  If you use it without supplemental oxygen, it performs horribly.  

After a terrible night of endless hypopneas (which I hardly ever see) and the highest AHI I've had in a long time, the lesson I learned is to keep a non-oxy tube handy in case I can't/don't use supplemental oxygen.

[Akeyla]

Pretty much my exact experience.  It just wasn't behaving correctly regardless of mask or settings.  Usually when I use my F40 mask, I have higher AHI numbers, like 2-3 (and thus I rarely, basically never use it).   I tried that mask with the Oxy hose and I was hittting 9 - 12, it was absurd, mostly hypopneas.  Generally with my N30 mask I get .2 - 1 AHI, I tried it with the Oxy hose and was getting 4 AHI.  And I'm not using it with supplamental oxygen.  I had watched the video were the Aussie said bigger hose is good so thought I'd give it a try, didn't work out.

Went back to my N30 with normal ClimateLine 15mm last night and slept a happy .5AHI.

Good to know it's not just me, thanks!

[mogulman]

I sleep with oxygen and have been using an Autoset 10 with Climateline Oxy for like 10 years. I have 3 different machines now and they have all worked the same with oxygen attached or without it attached (and cover over oxygen intake).

I don't bring my oxygen with me when I'm travelling and use an Autoset 10 with a standard climateline tube now, but I used to use an OXY climateline. Didn't see any difference in my numbers.

[SarcasticDave94]

Maybe a silly question, but are the Oxy hoses that's not working with the machine currently, as in Auto reporting the type, they're bonafide ResMed hoses or are they generic?

[Akeyla]

No they're real, brand name ResMed, purchased from vendor #38.

That math tells me that a 15mm ID hose with length of 78" holds a total volume of .012 cubic feet, while a 19mm ID hose with length of 72" has a volume of .018 cubic feet.  Which comes out to be a 50% increase in total air volume between the two hoses.  I'm guessing the system isn't taking that added volume into account.  But it's just a guess.

[srlevine1]

That math tells me that a 15mm ID hose with length of 78" holds a total volume of .012 cubic feet, while a 19mm ID hose with length of 72" has a volume of .018 cubic feet.  Which comes out to be a 50% increase in total air volume between the two hoses.  I'm guessing the system isn't taking that added volume into account.  But it's just a guess.

It is not the volume of air that is important to your xPAP therapy but the pressure at which air is delivered through the mask. Because ResMed does not release public information on its sensors, feedback loops, or algorithmic interpretations, everything is a guess, and you must trust ResMed. One might assume that the smaller hose diameter would deliver a higher pressure, however, you do not know what the feedback from the algorithm is telling the turbine. 

We can trust, but we often cannot verify, except at the most fundamental levels, like inserting a manometer into the loop and measuring pressure at the mask inlet.

[StuartC]

A quick comment about physics related to the statement "you're also piping O2 into the nipple which will increase pressures".

I don't believe pressure is increased by the addition of oxygen.  If it was, it could either become possible for reverse flow to occur from the oxygen input nipple back towards the turbine (because flow happens from high pressure to lower pressure); or mask pressure could become higher than desired.  Instead, the supplemental feed is flow controlled with the oxygen concentrator increasing its delivery pressure relative to the pressure in the tube by as much as is needed to achieve the target flow. 

If the pressure in the tube is unchanged and all other aspects of machine, tube, mask and user are unchanged, adding a supplemental flow simply means that less of the total flow down the tube comes from the CPAP machine.  If flow though the CPAP is measured and used for calculation of tidal volume, leaks or anything else, then the additional flow becomes interesting because of the unknown amount added to it.  I have no idea how the machine deals with this.

I have also been trying to work out the effect of a larger tube.

The obvious one is that flow resistance is lower so the turbine pressure needs to be lower to achieve the desired mask pressure.  For laminar flow, volumetric flow ~ (turbine pressure - mask pressure ) / flow resistance.  It's a bit more complicated for non-laminar flow but the same basic relationships will apply.  However, the machine knows about this difference in flow resistance and should compensate well.

Volume may be a factor as inhalation draws air from the mask and tube and works to decrease pressure in them (Boyles Law).  The potential pressure drop and rate of change should be greater with the smaller volume in a narrow tube and small mask (e.g. pillows vs FFM), and so the turbine will need to react faster and more to compensate.  If it does, no problem.  If it were either inaccurate or slow to react, it might not feel so great.