Does hypoxia = brain damage?

[Pi1otguy]

I took my girl cousin on a flight at about 4,500' & 5,500' for the first time. She has asthma (12+ yrs, well controlled) and was fine on the ground (100' msl), but to both our surprise after 10 or so minutes at 4,500' she became sleepy. I'm assuming this was a symptom of a mild hypoxia as she was still coherent when I spoke to her and did not appear to be high. I also noticed that when we landed she took another 5 - 10 minutes to become fully awake. Obviously I felt fine during the whole flight. Either I'm adjusted to the "quick" altitude changes or I don't use a significant portion of my brain to fly.

1. Am I correct in calling this hypoxia at only 4,500'?
2. Does hypoxia cause brain cells or other tissues to start dying? (from lack of O2?)
3. A friend of mine who smokes wants a ride. Will he likely face the onset of hypoxia at such low altitudes too?
4. Is the lower onset caused by lung issues or just a general difference in the general population?

 

[KennyFlys]

Great question. I'll be interested in Doc Bruce's answer as I've never thought about asthma.

I know the FAA books teach smoking will reduce your lung's ability to absorb more oxygen. I don't know enough about asthma to understand its effects.

 

[jesse]

I don't think 4 or 5 thousand feet is going to be an issue for most people, smoking or not. The airliners run higher cabin altitudes.

 

[bbchien]

At 4K to 5K the air is nearly completely dry. This can precipitate bronchospasm in many asthmatics, and the "ten minutes after down" would be consistent with recovery. At 4,500 feet she may have been having silent asthma, and supplemental oxygen would have been a GREAT thing. A pulse oximeter is pretty mandatory for these pax, and O2 on board as well. Some asthmatics carry an epinephrine "pen" for self administration for just this sort of spell. It can be life threatening.

You don't get lasting brain damage if the oxygen saturation stays above ~60% in the asthmatic but if it gets much below that, WATCHOUT. It's why Chronic Obstructive Pulmonary Disease is a special issuance at CAMI.

The Airline cabin, though at 8000 pressure altitude, is not totally dry and therein lies the difference.

Smokers also have reactive airways. They get the pulse oximeter treatment, too.

 

[Pi1otguy]

I guess I'll have to invest in an oximeter and possibly a small portable (10-20 minutes?) "emergency" O2 tank for future pax. I will also have to ask her if she felt the "silent asthma" that Bruce mentioned since I didn't notice any wheezing or labored breathing that I normally associate with asthma attacks.

I'll assume we were no where near 60% SPO since she was still coherent and decently responsive.

Once I get the oximeter and O2 tank should I administer it at a certain %SPO (<88%?), after a certain drop from ground level %SPO, or based on behavior?
Should I suggest that my smoker friend avoid lighting up within 2 or so hours before the flight?

Looks like I'll have to add "If you feel euphoric, fatigued, or become incoherent of no apparent reason please notify the pilot." to my pax brief. It never stops growing.

 

[sba55]

Smokers are always hypoxic, even at sea level. It's like being at 8000' all the time.

Yet another reason not to smoke....

I went to the high altitude training that CAMI offers at Beale AFB a few months ago. You learn a ton about this stuff and get to experience hypoxia first-hand (if you go to the air force, you also get some awesome pictures out of it ). Highly recommended.

-Felix

 

[SkyHog]

Of course, if you listen to the FAA, standing on the ground in Albuquerque, you're hypoxic already. The FAA is a joke in regards to giving accurate information about hypoxia. Better to listen to folks who have experience or better yet, doctors.

 

[Pjsmith]

Of course, if you listen to the FAA, standing on the ground in Albuquerque, you're hypoxic already.

I have extended family there. This explains a great many things.......

 

[ScottM]

Of course, if you listen to the FAA, standing on the ground in Albuquerque, you're hypoxic already. The FAA is a joke in regards to giving accurate information about hypoxia. Better to listen to folks who have experience or better yet, doctors.

I moved to Albuquerque form England. Where I lived in England was 16 feet above mean sea level. Upon arrival in Albuquerque I went out for a run that first morning. I almost passed out from hypoxia. I eventually acclimated to the mile high altitude in the city. But those first few weeks were really rough.