Question High Altitude Athletes.... Less efficient at depth?

[Doc Harry]

Do high altitude athletes respond to PCO2 more efficiently?

Yes, they blow off excess CO2 with a faster respiratory rate, and increase their O2 through purse-lip breathing, aka "auto-PEEP."

 

[tarponchik]

Totally false

Just FYI, In fact, the breathing reflex is not triggered by oxygen deficiency, but by carbon dioxide excess

 

[Vicko]

Hypoxemia and hypoxia are not the same thing. By the time you get hypoxemic due to breathing inert gas you are already passed out.

 

[Vicko]

Your reply to me wasn't my comment...

Whopse. Wanted to respond to this but deleted it.

I'm working with a highly motivated diver who I can't move out of the pool.

He cannot stop exhaling through his nose (problem 1) and his air consumption is so high that it appears that there is a constant stream of bubbles coming from his mask (and I'm not exaggerating).

He is the first student that I've considered putting in a full-face mask just to vary things up a little and maybe slow down his breathing. It's bizarre.

I've had three other instructors look at him and each, when seeing the bubbles coming from his mask, said that they didn't believe a human could do what this guy was doing. I should shoot some video and post it in the I2I...

I had a few students like that and they all had trouble closing of their nose. What helped some of them was training the frenzel fattah method, https://www.freediving.life/wp-content/uploads/2017/08/39188787-frenzel-fattah-english-r2006.pdf

Also waterbording with the snorkle but no mask works, but is inhumane especialy when the person actually can't controll their epiglotis. Does he have some sort of a speach impediment?

 

[kinoons]

I've performed emergency intubations of quite a large number of people - literally thousands - who were hyperventilating and plunging into respiratory failure due to hypoxemia (low O2) not hypercapnea (high CO2). Blood gasses showed a reduced pCO2 from hyperventilation, and a pO2 that has NEVER been even close to 60mm. At 60mm most people are unconscious and dark blue. We don't let them get that far. It doesn't take much hypoxemia (low O2) for people to start getting very anxious and start struggling to breathe, and they'll tell you "I CAN'T BREATHE!" If other measures don't help they get too exhausted to breathe and often that's when they get intubated.

I've also performed emergency intubations of thousands of people with hypercapneic (high CO2) respiratory failure. Different problem, different clinical picture.

It’s a little disengenious to equate a patient in an emergency setting to a diver who is trying to figure out their air consumption when diving. One has a very real physiological problem, be it from infection, disease exacerbation, poisoning, clot, etc. The other has no apparent disease process at all and is likely healthy enough to not deviate from anatomical and physiological norms.

It is fair to say that for a healthy individual CO2 is usually the driving factor in the need for respiration, not O2.

As a side note; physicians have long been accepted and revered as teachers as much as clinicians. I get that adults are responsible for their own learning, but if you have an educational pearl to add to the discussion I sure would love to hear it.

 

[pauldw]

Totally false.

I guess we'll see. Alabama is about to do a study of that.

 

[Doc Harry]

It’s a little disengenious to equate a patient in an emergency setting to a diver who is trying to figure out their air consumption when diving.

Are you claiming that I equated the two?
If so, prove it.

 

[FishWatcher747]

I've performed emergency intubations of quite a large number of people - literally thousands - who were hyperventilating and plunging into respiratory failure due to hypoxemia (low O2) not hypercapnea (high CO2). Blood gasses showed a reduced pCO2 from hyperventilation, and a pO2 that has NEVER been even close to 60mm. At 60mm most people are unconscious and dark blue. We don't let them get that far. It doesn't take much hypoxemia (low O2) for people to start getting very anxious and start struggling to breathe, and they'll tell you "I CAN'T BREATHE!" If other measures don't help they get too exhausted to breathe and often that's when they get intubated.

"other measures" If hyperventilating and otherwise healthy breathing into a paper bag to increase CO2 levels to normal may reverse the anxiety and hyperventilation spiral.

 

[kinoons]

Are you claiming that I equated the two?
If so, prove it.

Earlier in the thread when other posters said that CO2 was the normal driving factor in causing respiration you said they were wrong; specifically, “totaly false”. Multiple times IIRC. Then you gave your example of emergency intubations to support why CO2 may not be the reason why a patient feels short of breath or may not be the driving factor in a patient's respiratory drive. while you did not overtly equated the two, you certainly implied so.

I too am an emergency medicine clinician; paramedic, RN, and emergency nurse practitioner, so I have a more than passing familiarity with the respiratory system and respiratory drive. I do understand there are circumstances in which CO2 may, or may not, be the driving factor in how and why a patient is breathing (or not). Same goes for O2.

So I’ll reiterate, if there is some pearl you would like to add to the discussion about diving and what are likely (more or less) healthy individuals, I would love to hear it. I am not a physician and an open to learning from my colleges with more training than I have.

 

[Blackcrusader]

So, I live at around 5,500 ft above sea level, never smoked, and have decades of regular, long aerobic exercising at altitudes above 7,000 ft. Even with a 100 cu ft tank, I average about 25% less bottom time than most lifetime sea-level smokers on a 72 cu ft tank, whose only exercise is regular walks from the sofa to the fridge.

I thought I was an outlier until I ran into a retired, and quite fit high altitude mountaineer who's also experienced the same frustrations. I get back in the boat with less than 30 bars and Heinrich and his buddies will have over a 100 (then light up as soon as their suits are off). Sure, two data points do not make a trend, nevertheless, should I move to the coast and start smoking 3 packs a day?

Is there something about being aerobically unfit that is well suited for scuba diving? Can a diver with borderline emphysema stay down far longer than a Peruvian gold miner?

I live in the mountains in Taiwan above 3000ft - 5000ft or higher depending on where I am at any given time. I'm on old fat dude weigh 300 pounds. I take daily walks with my dog. You will find that your diving technique also can determine your gas consumption. Maybe your friends move on dives like they do from the sofa to the fridge, slowly lol.

I like to go slow on dives, it's not a race from point a to point b. Some people chase things. Me I get buoyant let the current carry me along if there is any. Sometimes I may hover barely doing anything other than a helicopter kick or back kick.

Can read about some gas usage I have on this dive.

Trip Report - Padangbai (Bali) Report: Geko Divers August '23

Yesterday a diver got separated from his guide in fast currents. Not Geko Divers. Diver was found by a fast boat ferry passing by so that diver was lucky. Anyway today the marine police were out checking the documents of dive operators, checking crew and customers. Vis is maybe 20m and you...

scubaboard.com

This is one of my guides I dive with in Philippines. We go at a nice slow speed. On my recent dives in Bali I had the guide follow me, at my pace. Sometimes he would point to something for me of interest, yet my speed to get to see what it is remains the same, slow.


This is a video a dive buddy took of me. From the first bubble trail you see count to the second bubble trail. So on this dive at around 100 feet depth I am only breathing 4 times a minute. Yet the diver in front of me had bubble trails often he is using gas at a much higher rate.