Are you sure you mean hypoxia? Hypoxia is not normally a concern...
There may be other justification for our hypoxia concerns, especially when without a breathable atmosphere, while using a regulator and pressurized air (or SNUBA). That's a strange notion, "without a breathable atmosphere." Maybe as in a smoke filled room during a house fire; if the rescuers are wearing breathing apparatus and enter a dangerous atmosphere, they won't be able to remove the gear if the air supply is bad.
* excess exertion (body begins to demand more than capacities)
* cigarette addicts (carboxyhemoglobin note:
"Physiologists have found that smoking raises normal carbon monoxide levels in the blood three to 12 times. This can impair tissue oxygen transport and carbon dioxide elimination, particularly in people with coronary artery disease. Circulation increases so uncontaminated red blood cells can meet tissue gas-exchange requirements, raising blood pressure and heart rate. This is one reason why smoking stimulates the heart." ~ The Encyclopedia of Recreational Diving, 2008© PADI Inc., Chapter 5, The Diver Within, "the Physiology of Diving," pg. 5-17)
* moisture in the air tank
* illness (and/or prescription drug use)
* shallow breathing during the dive
* fear
* tank gasses not analyzed immediately before the dive
* amateur refills (Not filled per safety standards; such as OSHA or CGA)
* age of air in the cylinder (also non-diving cylinders or using condemned SCUBA tanks)
I've seen many compressor air intakes located with engine exhaust up-wind. What about technicians that eat a lot of beans before filling your air tank?
It may be impossible to determine if a person's death was caused by hypoxia (asphyxiation?) because issues may be cited as the cause of death that were identified by hypoxia being one of the symptoms. But I mention that to suggest the opposite; hypoxia may be temporary or not cause an incident that gets DAN's attention, and thus, becomes overlooked.
Wait. Um, that's not expressed clearly. I have an example of what I'm try to say:
1. I witnessed, what appeared to be a 12 year old girl (reported to be a "14-year-old"), arrive to the ER unconscious due to prolonged hypoxia caused by shallow breathing (dyspnea?) and inadequate heart rate which was the result of her having a reaction to what the estacy was cut with; she died a few days leter.
http://www.justthinktwice.com/itcant/irma.cfm2. Victims of confined space entry (without a marine chemist and/or a breathing apparatus) may die due to lack of immediate first aid to correct a slow heart rate and inadequate breathing caused by hypoxia from breathing air in the oxygen deficient confined space.
Is that expressed better? In both cases the victim looks as if merely sleeping soundly. In both cases prompt oxygen first aid, may have resulted in a rapid full recovery for either or both victims.
Would you be surprised to know at what O2 percentage we loose consciousness?
Would you be surprised to know how long an unconscious victim of hypoxia can go without first aid before permanent brain damage results?
Are you absolutely sure you have NEVER EVER been able to taste or smell the compressed air you were breathing on SCUBA/SNUBA, hard-hat, or SCBA systems?
Edited by Wakemaker, 11 September 2009 - 11:51 AM.
SDHH in Seattle this weekend? Hum? What did you say? I just need to know. Tell me it is so!