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This is a multi-part message in MIME format. ------=_NextPart_000_007F_01C1B1FD.C298A370 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit As a dope's explanation of the oxygen window concept for you Marines, the best gas differential would be a vacuum relative to a partial pressure, right? Oxygen is the next best as it creates a similar effect in that the sum of the gas partial pressures is unbalanced by the fact that some of the oxygen is metabolized, more in a fit person. The greater the difference between the oxygen and the other gases up to the max differential described by the metabolism ( maximum window ) , the greater the propensity for whatever is in the cells to come out and be displaced. For a fit person, the widow is wider and by definition so is his vascularity and perfusion, so he decompresses better. These things are all tied together. You open the widow as wide as possible subject to 1) risk of tox or damage, 2) how long before the vaso constrictive effect offsets the benefit, 3) how long before the asthma like reaction sets in. You then alternate the process back to open up the vessels and lungs again, and repeat. All part of a good deco. Also it can be said that the sum of the inert gases is the other side of the oxygen window minus the metabolism drop of oxygen- there is no benefit to combining inerts - they act like one gas. Oxygen can be pushed to above its partial pressure effectiveness as a result of this imbalance for a "window" that then exceeds what would be the net effect of the partial pressures of the gases, and this is especially important in diminishing bubbles of inert gas as the pressure of the bubble can always be faced with a negative gradient or "tension" on the outside due to the fact that metabolized oxygen is creating a "vacuum" in the total sum of the partial pressures of the gases, leaving a consistent imbalance between bubble pressure and surrounding tension of any given inert. This is why oxygen ( pure, not 80/20) works so well in DCS cases after the fact to reduce bubbles, as well as the fact that saturation with oxygen tends to move that gas to where it is needed even if the vessels are blocked by damage. Capice? For you geeks, see Eddie Bryan's explanation. When you are done with all that, go back and see what I said about how to decompress. How is all the matters. ------=_NextPart_000_007F_01C1B1FD.C298A370 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=3DContent-Type content=3D"text/html; = charset=3Diso-8859-1"> <META content=3D"MSHTML 5.50.4522.1800" name=3DGENERATOR></HEAD> <BODY> <P><SPAN class=3D290453411-10022002>As</SPAN> a dope's explanation of = the=20 oxygen<SPAN class=3D290453411-10022002> </SPAN>window concept for you = Marines, the=20 best gas<SPAN class=3D290453411-10022002> </SPAN>differential would be a = vacuum=20 relative to a partial<SPAN class=3D290453411-10022002> </SPAN>pressure, = right?=20 Oxygen is the next best as it<SPAN class=3D290453411-10022002> = </SPAN>creates a=20 similar effect in that the sum of the gas<SPAN = class=3D290453411-10022002>=20 </SPAN>partial pressures is unbalanced by the fact that<SPAN=20 class=3D290453411-10022002> </SPAN>some of the oxygen is metabolized, = more in a=20 fit<SPAN class=3D290453411-10022002> </SPAN>person. The greater the = difference=20 between the<SPAN class=3D290453411-10022002> </SPAN>oxygen and the other = gases up=20 to the max<SPAN class=3D290453411-10022002> </SPAN>differential = described by the=20 metabolism ( maximum<SPAN class=3D290453411-10022002> </SPAN>window ) , = the=20 greater the propensity for whatever<SPAN class=3D290453411-10022002> = </SPAN>is in=20 the cells to come out and be displaced. For a<SPAN = class=3D290453411-10022002>=20 </SPAN>fit person, the widow is wider and by definition so<SPAN=20 class=3D290453411-10022002> </SPAN>is his vascularity and perfusion, so = he=20 decompresses<SPAN class=3D290453411-10022002> </SPAN>better. These = things are all=20 tied together.</P> <P>You open the widow as wide as possible subject to 1)<SPAN=20 class=3D290453411-10022002> </SPAN>risk of tox or damage, 2) how long = before the=20 vaso<SPAN class=3D290453411-10022002> </SPAN>constrictive effect offsets = the=20 benefit, 3) how long<SPAN class=3D290453411-10022002> </SPAN>before the = asthma=20 like reaction sets in. You then<SPAN class=3D290453411-10022002> = </SPAN>alternate=20 the process back to open up the vessels<SPAN class=3D290453411-10022002> = </SPAN>and lungs again, and repeat. All part of a good<SPAN=20 class=3D290453411-10022002> </SPAN>deco.<SPAN = class=3D290453411-10022002>=20 </SPAN>Also it can be said that the sum of the inert gases<SPAN=20 class=3D290453411-10022002> </SPAN>is the other side of the oxygen = window minus=20 the<SPAN class=3D290453411-10022002> </SPAN>metabolism drop of oxygen- = there is no=20 benefit to<SPAN class=3D290453411-10022002> </SPAN>combining inerts - = they act=20 like one gas. Oxygen can<SPAN class=3D290453411-10022002> </SPAN>be = pushed to=20 above its partial pressure<SPAN class=3D290453411-10022002> = </SPAN>effectiveness=20 as a result of this imbalance for a<SPAN class=3D290453411-10022002>=20 </SPAN>"window" that then exceeds what would be the net<SPAN=20 class=3D290453411-10022002> </SPAN>effect of the partial pressures of = the gases,=20 and<SPAN class=3D290453411-10022002> </SPAN>this is especially important = in=20 diminishing bubbles<SPAN class=3D290453411-10022002> </SPAN>of inert gas = as the=20 pressure of the bubble can<SPAN class=3D290453411-10022002> = </SPAN>always be faced=20 with a negative gradient or<SPAN class=3D290453411-10022002> = </SPAN>"tension" on=20 the outside due to the fact that<SPAN class=3D290453411-10022002>=20 </SPAN>metabolized oxygen is creating a "vacuum" in the<SPAN=20 class=3D290453411-10022002> </SPAN>total sum of the partial pressures of = the=20 gases,<SPAN class=3D290453411-10022002> </SPAN>leaving a consistent = imbalance=20 between bubble<SPAN class=3D290453411-10022002> </SPAN>pressure and = surrounding=20 tension of any given inert.</P> <P>This is why <SPAN class=3D290453411-10022002>oxygen ( pure, = not=20 80/20) </SPAN>works so well in DCS cases<SPAN = class=3D290453411-10022002>=20 </SPAN>after the fact to reduce bubbles, as well as the<SPAN=20 class=3D290453411-10022002> </SPAN>fact that saturation with oxygen = tends to move=20 that<SPAN class=3D290453411-10022002> </SPAN>gas to where it is needed = even if the=20 vessels are<SPAN class=3D290453411-10022002> </SPAN>blocked by = damage.</P> <P>Capice?<SPAN class=3D290453411-10022002> For you geeks, see Eddie = Bryan's=20 explanation. When you are done with all that, go back and see what I = said about=20 how to decompress. How is all the matters. </SPAN></P> <DIV><FONT face=3DArial size=3D2></FONT> </DIV></BODY></HTML> ------=_NextPart_000_007F_01C1B1FD.C298A370-- -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
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