We were told of all of the symptoms you mentioned in Air Force pilot
training. And, though I flew a lot at cabin altitudes up to 25,000'
MSL, I always used a diluter demand mask and regulator and had no
symptoms whatever. Some on this group may dispute that!
I once had the joy of cabin decompression at FL450 but, other than
learning first hand about pressure breathing, suffered no ill effects.
An emergency descent kept the time at altitude to a minimum.
I made two glider flights to FL290 but was using a military mask and
regulator for those and had no ill effects or symptoms. I now fly often
to just below FL180 in my glider using a Mountain High cannula and
regulator. I set the regulator at 5,000' which, at Moriarty, NM, is
below ground level. I have noticed a rare head ache but I've attributed
those to dehydration since I don't always drink enough water.
Thanks for spreading the word about oxygen use and cabin pressure!
Dan
5J
On 3/13/23 17:06, danlj wrote:
Many of you know me as DrDan Johnson, once a regular SoaringRx writer, now languishing in retirement.
I very much want to hear from any pilot who may have had decompression symptoms, or know of any who has. I especially want to hear about pilots who became chronically crabby after a high wave flight.
drdan AT wwt.net or 715 556 2319 text or voice.
--- rationale ---
At SSA, preparing for a talk on oxygen, I found a brilliant paper on Altitude Decompression Sickness that revealed that many of us have tiny bubbles in our blood beginning at about 15,000 msl and most of us, in an unpressurized cockpit, will have
decompression symptoms above about FL212 -- if we care to pay attention.
DCS symptoms are: joint pain (60-70% of cases), especially knee, hip, and ankle -- or skull (~20% of altitude headaches). or
- weird skin sensations (15-30% of cases) of almost any kind, or skin rash (red blotches are serious and require hyperbaric treatment).
Serious DCS is rare but does happen, somewhat unpredictably: brain and lung. DCS has injured the brains of perhaps 2 wave pilots and many U-2 pilots (cockpit pressure FL250 until 2013, then FL150, which stopped their DCS events)
Risk for DCS includes
- altitude (doh) - has occurred in the teens, but is common above FL212
- duration aloft (generally more than an hour at altitude)
- rate of climb (scratching slowly upward decreases risk, a 5-10 kt elevator increases it, but actual risk hasn't been defined by research)
- failing to pre-breathe 100% oxygen or not using this during flight (hello, all wave pilots!)
Unknowns:
- age has not been evaluated over 40
- does canula O2 or casual face mask reduce risk? not evaluated
- Do the brain lesions with brain-DCS portend dementia? (They do with traumatic brain injury, but only bring it on ~3 years earlier than usual.)
Thanks!!
--- SoupGate-Win32 v1.05
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