From Air to Trimix at depth

[Pullnglide]

I have done 165' on air and was messed up worse than a football bat! Did a dive later that day to 175' on tmx and it was a night and day difference!


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[dreamdive]

Oxgen has a higher molecular weight and a higher density than nitrogen?

Here are some numbers for comparison:

Density in g/L:
Oxygen 1.428
Nitrogen 1.251
Helium 0.178

Density difference between Oxygen and Nitrogen is negligible.

 

[DiverRtNY]

Argh, i think my thought process is faulty with pneumothoraces and high oxygen and nitrogen washout. Oxygen is easier to absorb through the permeable membrane. Hence why under higher atmospheric pressure it is absorbed. nitrogen washout for pneumo works because in the pleural space is air. Give high oxygen and the nitrogen diffuses down gradient to lower concentration of nitrogen in pleural space. Oxygen in pleural space is then easier to diffuse and over time will alleviate the pneumo. My thoughts were wrong. Nitrogen still helps to keep airways open because it isn't diffused through the permeable membrane under 1 atm pressure.
Apologize for my misdirection and misconceptions applied to that concept. Density and mass is negligible :footinmouth::fail:

 

[dumpsterDiver]

Here are some numbers for comparison:

Density in g/L:
Oxygen 1.428
Nitrogen 1.251
Helium 0.178

Density difference between Oxygen and Nitrogen is negligible.

Yes, thank you for verifying the correctness of my comment.

I never said the difference was significant, but the comment was made that nitrogen's higher density has certain physiological consequences. I am not qualified to judge the veracity of those conclusions, but the premise of them certainly was faulty.

I would think oxygen might be more readily absorbed in an air space because it would be metabolized but I have no real basis for that guess.

 

[Storker]

Oxgen has a higher molecular weight and a higher density than nitrogen?

Yes.

opposite

No.

As I learned in high school chemistry (or was it my very first undergrad chem course?), M(O2) = 32 g/mol, M(N2) = 28 g/mol and 1 mol of any gas is 22.4L at STP.

Ergo...


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Typos are a feature, not a bug

 

[TONY CHANEY]

opposite

---------- Post added October 25th, 2014 at 09:39 AM ----------



What belief are you pertaining to? Debate away...

CO2 retainers and knocking out their hypoxic drive to breathe.

 

[DiverRtNY]

CO2 retainers and knocking out their hypoxic drive to breathe.

What part of the concept are you debating? I guess define what you feel is in question. I'll use ABGs for same co2 retainer...
option 1 : On 100% oxygen has a PaO2 of 64 w/ SaO2 of 92% w/ Ph of 7.36 PaCO2 of 67 HCO3 of 36
option 2 : On 50% oxygen has a PaO2 of 257 w/ SaO2 of 99% w/ Ph of 7.36 PaCO2 of 67 HCO3 of 36

Option one, although is receiving 100% by NRB is not hyperoxic but patient 2, also receiving 100% is hyperoxic. Option 2 will have impedement of hypoxic drive and GUARANTEE will go into hypercapneic respiratory failure before option 1. First cicumstance is clearly under a significant shunt but is stable with 100% oxygen/ Ph is norm for retainer, PaCO2 is norm for retainer and HCO3 is norm. Patient is given needed oxygen therapy. Option 2 is being over oxygenated and within a few hours will have an ABG showing more acidotic with more elevated PaCO2.
This is a good article... Oxygen: kill or cure? Prehospital hyperoxia in the COPD patient
This article is a warning for EMT crews and therapy but covers all the bases and concepts of hyperoxia induced hypercapnia