Oxygen: Mountain High vs. Precise Flight

[Davidv]

I'm considering upgrading to a better oxygen system and was curious if anyone had a better experience with the Precise X3 vs. the Mountain High 02D2.  My current A5 + oxymizer works OK, but I feel like it's always slipping out of my nose and a boom style would ensure that I'm getting enough oxygen throughout the flight (I check with an oximeter periodically and sometimes I'm lower than I'd like).  I could just get the boom sold by precise flight with my A5 but I'm thinking that will use too much oxygen without the oxymizer?  I'd appreciate anyone's advice!

[carusoam]

There are plenty of people around here running the O2D2...

And a few with cascade systems in their hangar...

Looks like precise flight has a favorite aircraft manufacturer...

https://www.preciseflight.com/general-aviation/shop/product/preciseflow-demand-conserver/

Best regards,

-a-

[smccray]

I run an O2D2.  I can't speak to the X3, but the MH system works well.

[N201MKTurbo]

I have a precise flight and it has been a reliable performer. 

I have flown with O2D2 also. It worked fine too.

the difference I noticed was the Precise flight has you drawing in the oxygen with your breath, the O2D2 kind of shoots a blast of oxygen in. I never notice the flow with the precise flight, but I do with the O2D2.

[KSMooniac]

I have the PF conserver (just one station) and have been very pleased, although I'm an infrequent user. I don't think you can go wrong with either choice.

Sent from my LG-US996 using Tapatalk

[gsxrpilot]

O2D2 fan here. I regularly fly above FL200 and like the reassuring sound the O2D2 makes giving you the shot of O2. If I don't hear that sound, I know I'm not getting any.

[N201MKTurbo]

The difference is the PF gives you oxygen depending on how big a breath you take. The O2D2 gives you the same O2 on every breath.

[TTaylor]

I fly with an O2D2 system in the Mooney and an original EDS in my glider.   I am biased because I am friends with the the founder of MH, but I know there is a great deal of physiology behind the MH systems.  The pulse strength and duration are designed to optimize oxygen delivery.  I like that you can set the MH to an altitude and it will turn on and off automatically. It also monitors if you are not breathing enough and gives you reminders.

[Bolter]

1 hour ago, gsxrpilot said:

O2D2 fan here. I regularly fly above FL200 and like the reassuring sound the O2D2 makes giving you the shot of O2. If I don't hear that sound, I know I'm not getting any.

+1 on that.  I consider the pulse to be a good indicator, especially since I use a portable system, and the tank and gauge are out of sight.  With noise cancelling headset, I can hear the audible alarms from the O2D2, barely.  

I got the boom attachment, too.  Not perfect positioning for comfort (maybe my fault), but very convenient when paired with the quick release connector.  Overall very happy with the Mountain High package.  

[slowflyin]

MH 02D2 for me as well.  O2 last forever and as gsxpilot said the pulse is reassuring.  

[Bryan]

O2D2 for me, too.  LIke others (above), the electronic monitor of O2 flow is nice.

[donkaye]

6 hours ago, slowflyin said:

MH 02D2 for me as well.  O2 last forever and as gsxpilot said the pulse is reassuring.  

Amazing!  I never could get the O2 saturation level above 93 with the O2D2.  I like at least 96% for sea level alertness.  I sent it back.  After the fact MH told me  that with the altitude compensation unit in the Bravo it wouldn't work.  It didn't for me.

[Davidv]

Thanks @donkaye and everyone else who responded.  Does anyone with an 02D2 and a Bravo see higher 02 readings?  The main reason why I'm looking into a system is to get 95%+ saturation without setting my A5 to full blast.  

[jaylw314]

11 minutes ago, Davidv said:

Thanks @donkaye and everyone else who responded.  Does anyone with an 02D2 and a Bravo see higher 02 readings?  The main reason why I'm looking into a system is to get 95%+ saturation without setting my A5 to full blast.  

I would be careful about reading too much into O2 saturation.  While it does indicate generally how much oxygen you're getting, the actual number does NOT correlate with performance.  Other factors are more significant in terms of circulation and physiological responses to altitude.  I would think of it more as a yes/no measurement

[slowflyin]

42 minutes ago, donkaye said:

Amazing!  I never could get the O2 saturation level above 93 with the O2D2.  I like at least 96% for sea level alertness.  I sent it back.  After the fact MH told me  that with the altitude compensation unit in the Bravo it wouldn't work.  It didn't for me.

I had ask them about the Bravo because I had seen one of your previous post.  They recommended a small regulator between the ceiling port and their unit.  Seems to be working well.  I've got maybe 25 hours of utilization.   Is the Bravo system unique?  I assumed many models had the same altitude compensating regulator.  Maybe mine is not working properly.  How much flow do you get at sea level?    I will say that no matter what kind canula type O2 system I use my saturation can drop if I'm not cognizant of my breathing.  I tend to go into shallow breathing mode.  I've checked it at my desk (400' MSL) after a long sit at the computer and have found it below 93.   Truthfully I suspected the 39 dollar meter probably wasn't as accurate as I hoped.  If I take a slightly deeper breath my stats rise very quickly.   The wife does much better.  She never seems to fall below 93 and is normally 95 or higher.  

[Davidv]

I'm usually 98+ at sea level but easily be at 80 without oxygen above 10-12K.  If I set my A5 to a high altitude setting I can get over 93-94.  I'm not sure how low this is, but I'm a non-smoker and in reasonable shape. 

[donkaye]

1 hour ago, jaylw314 said:

I would be careful about reading too much into O2 saturation.  While it does indicate generally how much oxygen you're getting, the actual number does NOT correlate with performance.  Other factors are more significant in terms of circulation and physiological responses to altitude.  I would think of it more as a yes/no measurement

No matter what you say, I can definitely tell the difference between 93 and 96 and 96 is what I feel comfortable with.

[jaylw314]

11 minutes ago, donkaye said:

No matter what you say, I can definitely tell the difference between 93 and 96 and 96 is what I feel comfortable with.

If more oxygen at a given altitude makes you feel or perform better, that's the outcome you're looking for.  I would simply claim that numbers between 90-100% are within the range of "noise" and how you feel is a much better reflection of your oxygen status.

[smccray]

32 minutes ago, jaylw314 said:

If more oxygen at a given altitude makes you feel or perform better, that's the outcome you're looking for.  I would simply claim that numbers between 90-100% are within the range of "noise" and how you feel is a much better reflection of your oxygen status.

I sense a professional gas man here...

The EDS has settings for a cannula and for a facemask.  If I leave the EDS on the cannula settings my SPO2 drops to the 80s unless I consciously breath deeply.  I usually set the EDS for the facemask setting and I stay comfortably in the 90s when flying.

FYI- wellness stress test due to 40th birthday.  Pulmonary function all normal- gas exchange 130% of mean.  I'm just sensitive to altitude.

[kortopates]

1 hour ago, slowflyin said:

I had ask them about the Bravo because I had seen one of your previous post.  They recommended a small regulator between the ceiling port and their unit.  Seems to be working well.  I've got maybe 25 hours of utilization.   Is the Bravo system unique?  I assumed many models had the same altitude compensating regulator.  Maybe mine is not working properly.  How much flow do you get at sea level?    I will say that no matter what kind canula type O2 system I use my saturation can drop if I'm not cognizant of my breathing.  I tend to go into shallow breathing mode.  I've checked it at my desk (400' MSL) after a long sit at the computer and have found it below 93.   Truthfully I suspected the 39 dollar meter probably wasn't as accurate as I hoped.  If I take a slightly deeper breath my stats rise very quickly.   The wife does much better.  She never seems to fall below 93 and is normally 95 or higher.  

Nothing unique about the Bravo, other than the engine model. All the Mooney airframes built-in O2 system use a 2 stage Scott regulator where the second stage is an altitude compensating one. The only differences in the system are in the size of the onboard tank.

[donkaye]

2 hours ago, jaylw314 said:

If more oxygen at a given altitude makes you feel or perform better, that's the outcome you're looking for.  I would simply claim that numbers between 90-100% are within the range of "noise" and how you feel is a much better reflection of your oxygen status.

I agree with the first sentence, not so with the second--at least for me.  At 92% I can feel just the slightest bit of light headedness that incrementally decreases with increase in O2 saturation. I could fly at 92%, but I wouldn't want to be limited to that like the O2D2 limits.  I added the supplemental inline regulator.  That did nothing.

[tgardnerh]

3 hours ago, jaylw314 said:

If more oxygen at a given altitude makes you feel or perform better, that's the outcome you're looking for.  I would simply claim that numbers between 90-100% are within the range of "noise" and how you feel is a much better reflection of your oxygen status.

That's definitely not what the doctors I have asked say.  Including the one I'm married to--she tells me that 92% is really the minimum she's comfortable with for patients who don't have COPD, and she emphasizes that 92% is good for keeping the heart healthy, but not good enough to be mentally sharp.

[M016576]

28 minutes ago, donkaye said:

I agree with the first sentence, not so with the second--at least for me.  At 92% I can feel just the slightest bit of light headedness that incrementally decreases with increase in O2 saturation. I could fly at 92%, but I wouldn't want to be limited to that like the O2D2 limits.  I added the supplemental inline regulator.  That did nothing.

That does make sense for you- you’re older, and living at sea level in a city with some level of particulate in the air- physiologically, a higher O-2 sat probably does make you feel better than say, a 25 year old that is acclimated (lives at) to 6000’ and is in clean air on a more regular basis.

A few references that discuss the topic:

https://perf2ndwind.org/about-chronic-respiratory-disease/altitude-oxygen-levels-and-oximetry/

http://www.high-altitude-medicine.com/SaO2-table.html

This particular issue is something that we discuss frequently in my line of work- especially due to the recent rash of OBOGS related “anomalies.”  O2 is typically something we want more of.. not less... although not always (hypocapnia being an example of that)

Edited September 5, 2019 by M016576

[jaylw314]

9 minutes ago, tgardnerh said:

That's definitely not what the doctors I have asked say.  Including the one I'm married to--she tells me that 92% is really the minimum she's comfortable with for patients who don't have COPD, and she emphasizes that 92% is good for keeping the heart healthy, but not good enough to be mentally sharp.

There's a difference there--in someone with COPD, we assume any decrease in oxygen saturation is the result of COPD.   For normal physiology at near normal oxygen saturation, the altitude may not be the primary factor, since heart output, physical activity, temperature, blood pH and other factors can affect the amount of oxygen that gets to the brain (which is the issue at hand).

Again, the gist of it is that if you're below 90%, turn it up (that's the oxygen saturation around 12,500 MSL).  If you're above 90% but feel off in any way, turn it up more.  But above 90%, don't just turn it up because of the number.

[ilovecornfields]

4 hours ago, M016576 said:

That does make sense for you- you’re older, and living at sea level in a city with some level of particulate in the air- physiologically, a higher O-2 sat probably does make you feel better than say, a 25 year old that is acclimated (lives at) to 6000’ and is in clean air on a more regular basis.

A few references that discuss the topic:

https://perf2ndwind.org/about-chronic-respiratory-disease/altitude-oxygen-levels-and-oximetry/

http://www.high-altitude-medicine.com/SaO2-table.html

This particular issue is something that we discuss frequently in my line of work- especially due to the recent rash of OBOGS related “anomalies.”  O2 is typically something we want more of.. not less... although not always (hypocapnia being an example of that)

Dude! You calling Don “old?!” He’s like a fine wine. He only gets better with age. 

Seriously, though. Have you met him? He’s in great shape. I wouldn’t make any assumptions about his pulmonary physiology lest he smack you over the head with his (excellent) landing DVD.

I asked my doctor wife about the oxygen levels, too. She responded by reminding me that she’s a psychiatrist. (Have you guys heard the joke about the naked guy wrapped in Saran Wrap who walks into a party and the psychiatrist looks at him and says “I can clearly see your nuts.”)

On a more serious note, I agree with @jaylw314. I think this oxygen thing comes up every year or so and the first time I posted about it I got attacked because I had the audacity to suggest that everyone get a pulse ox and keep their oxygen levels above 92%. Well, I’m going to do it again: get a pulse ox and keep your oxygen levels above 92%. If you like 98% more than 92% I have no problem with that. 100% is probably too much, but if you don’t have an accurate pulse ox more is safer than less.

The issue with COPD patients has to do with hypoxic pulmonary vasoconstriction and the fact that increasing their FiO2 (fraction of inspired oxygen) worsens their shunt and increases their pCO2. Those who don’t know any better will tell you it takes away their “hypoxic drive” and makes them stop breathing if you give them too much oxygen, but that’s really not the major player and anyone who’s managed a COPD patient on a ventilator can speak to the fact that this is NOT why we limit their FiO2.

O2D2 gets my vote. I have two in my plane and just spent $60 for a year’s supply of oxygen (I had about 800 psi left but it was in for annual and needed a hydro so I got it filled).