nitrogen narcosis

[wedivebc]

Me too...
Also, this statement make me wonder about partial pressures. So, say the loop had gas at 1ATA (just for discussion). If this gas was composed of 3 components (O2, CO2 and N2), in equal amounts (once again for discussion), they would each have a partial pressure of 1/3 ATA.

However, if we scrubbed out all the CO2 (just for discussion) in a closed system, that would leave only the O2 and N2 taking up the same space. Would the total pressure in the system drop below 1ATA, and would the partial pressures of O2 and N2 remain the same? (making the pressure of the total system like .66 ATA, 1/3 ATA + 1/3 ATA?)

First of all the pressure in the loop is ambient which we all know will be greater than 1ata when you submerge. In a semi closed system the scrubbed c02 is replaced by gas through the dosage device. In the event of high workload at let's say 2 ata your loop could contain a partial pressures more like:
po2 0.3 pn2 1.7.
Now what if we are at 115 ft (4.5 ata) and our loop is po2 0.5 and pn2 4.0? That gives us the same pn2 as 130ft on air.
One document says narcosis does not change due to fraction of o2 another says it does. Thats my point.

cheers,

 

[partridge]

Ive been reading up in this forum and noticed this thread was left hanging. Maybe 3 years later, someone has something positive to contribute.

 

[Xman]

I have something to contribute. Agencies contradict themselves.......quite often, and sometimes in print.
Since there is no absolute with narcosis, there are various theories. IMO the prevalent one seems to be that oxygen is just as narcotic as nitrogen. It would seem that the agency is question should review their materials and come out with a consistent view or their chosen theory of narcosis. Perhaps they already have? It has been a few years now.