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[H2Andy]

oh, sorry... the 10 ppm came from another article:

"Although CO levels in work environments should not exceed 20 parts per million, levels of CO in breathing air should not exceed 10 parts per million."

http://www.scubamed.com/divess.htm#anchor1722656

it's the third article down

 

[AtomicWalrus]

Interesting reading...

I hadn't thought of using hyperbaric treatment for CO poisoning, but if you think about it, it makes sense. Buy forcing more O2 into the tissues, you would accelerate the removal of CO.

The information does point out that the maximum allowed levels in diving are 0.002% though. Though when talking about 10PPM and 20PPM, the relative differences are still pretty small. I'd rather go with you figure for safety.

Yeah - hyperbaric treatment is pretty common for CO poisoning. Basically, with enough ppO2 you can carry enough O2 saturated in your blood plasma that you don't need the function of hemoglobin anymore. That's where it can potentially get REALLY scary - you get CO poisoning because of low level air contamination, but still get enough O2 because you're at depth. Then you surface, have to rely on your hemoglobin again (which is now saturated with CO), and you go hypoxic and pass out...

 

[Seabear70]

Basicly, I was trained fairly well on all of this in dive school, and I've taken some interest in it over the years, unfortunately my ex-wife messed up my chance to go to Dive Medic training so we are starting to get out of my depth. Wouldn't enough concentration of o2 at depth cause you to stop utilizing O2 in metabolism? If it effects you there, you are geting a lower volume on the surface, but the concentration would not change. Right?

 

[Seabear70]

Oops, diving doubles..

 

[Coogeeman]

Test the air that you go down with when you get a fill at the shop by breathing it, tasting it...unserviced or unloved compressors will have dirt, dust, oil and grease residue in its system and that residue can transport through to the air that you are breathing.

If it tastes bad at the test, get another tank. If that tastes bad inform the shop and move on. With regards to CO it takes very little CO to affect you: .002% in open air and .001% in confined (breathing) air.

Coogeeman

 

[nemisis77]

thanks all.... but what about the helicopter ride... does the height affect you if you have dcs or is it rare?

 

[Warren_L]

Actually, I've heard about a lot of instructors trying to pull students down. No one's ever tried that on me. If I want to go up, they let me, which is a good thing I think. Especially as my Ju-Jitsu Instructor used to make us practice underwater.

Don't mistake this for an instructor (or DM) slowing one's ascent. . One of the biggest concerns with a panicing diver bolting for the surface is too fast an ascent rate. If a student bolts to the surface on me, there might be little I can do to keep him down, so if he's going up, I make sure it is at a safe ascent rate.

 

[String]

Taste/Odour on the surface may well not detect a bad fill.

Only at depth with the partial pressure of the contaminent is increased may symptoms or side effects be noticed.

If you detect something on the surface you can be sure its a very VERY bad fill.

 

[Don Burke]

thanks all.... but what about the helicopter ride... does the height affect you if you have dcs or is it rare?

The chopper does have to stay low in order to avoid making DCS worse. For carbon monoxide, it would make little or no difference and spasms would not be the result anyway.

When I was on active duty, I served at several stations with chambers and we did more treatment for carbon monoxide than treatment for DCS. I talked to civilian hospital personnel and they told me that they do far more treatment for CO.

The spasms in the helicopter were the result of a screenwriter getting his reasons for a chamber mixed up. He added two and two and came up with seven.

 

[String]

CO poisoning and burns victims seem to be the main groups treated in chambers over here. It also helps make the symtpoms of MS a little better for a while.

Bent divers are actually a fairly low % of users for the average general chamber.