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This is a multi-part message in MIME format. ------=_NextPart_000_0016_01C1AED5.6CE9C010 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit -----Original Message----- From: George_Irvine@ Mike, I will put out my repet post and the others in sequence, but first let me mention something here that is being missed. Gas does not transfer from tissues into arteries or veins, it does so into capillaries. The artilleries coming from the heart are huge, thick, elastic , pulsing conduits that get smaller as they branch out until they become capillaries, and then the return to the heart is through veins which are also thick and get larger as they combine to return blood to the right side of the heart. That blood is then sent to the lungs, where the massive network of tiny capillary beds located in about 45,000 square feet of surface area, act as a "filter" for bubbles. The "filtered" and now oxygenated blood which has passed its co2 and other excess gasses to the lung space, goes back to the heart to be pumper through the system again. The whole trip takes about two minutes to happen. You do not bubble into the arteries. If bubbles get into the arteries it is because they passed the filter or were "shunted" over through a PFO in the arterial walls, or because they were momentarily compressed enough momentarily to get past the lungs and then reexpanded as the pressure dropped prior to reaching the capillaries, in which case they lodge in the smaller and smaller vessels and block them. This occurs in bounce diving, as in doing a dive and then bouncing back down to retrieve something, like a deco bottle. This is why we do not allow bouncing in the WKPP, and why we require our support divers to stay out for 4 hours before diving shallow for support. * If somebody wants to put that post on here, go ahead* Most people get the greatest rush of bubbles from the tissues into the blood stream upon surfacing from 20 feet or so. This is why we do that differently, post to follow. Most people tend to bubble for hours after a dive. Most bubbles tend to grow from the surrounding supply of gas before they get smaller and disappear. If the bubbles are in the tissues, yo have pain. The way to prevent bubbles in the tissues is to properly decompress starting deep and at a rate that allows the bubbles to escape to the blood stream. Deep this needs to be done carefully and in solution, shallow you can press the gradient and allow offgassing in bubble form into the blood stream. The difference is that if you screw up shallow, you can go back a little and fix it. If it occurs deep, that makes it impractical and a huge waste of time for nothing. For people wight cardiac or pulmonary shunts, offgassing in bubble form is super dangerous. For those without, it is far more efficient. For those with PFO's, the risk is greatest AFTER they get out of the water for the reasons stated above ( growth of bubbles and continuation of bubble offgassing) I think you can see where I am going to tell you that you need to do your shallowest dives first, do your drills before yo do your dives, and why you can basically ignore repetitive dives using the correct deco. You can NOT ignore them with respect to oxygen exposure. This post is long enough , basic enough and preliminary enough. Now we can go on to the whole bit. ------=_NextPart_000_0016_01C1AED5.6CE9C010 Content-Type: text/html; charset="US-ASCII" 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=3Dus-ascii"> <META content=3D"MSHTML 5.50.4522.1800" name=3DGENERATOR></HEAD> <BODY> <DIV><FONT face=3DArial color=3D#0000ff size=3D2></FONT> </DIV> <DIV class=3DOutlookMessageHeader dir=3Dltr align=3Dleft><FONT = face=3DTahoma=20 size=3D2>-----Original Message-----<BR><B>From:</B>=20 George_Irvine@</FONT></DIV><BR><FONT face=3Dsans-serif size=3D2>Mike, I = will put out=20 my repet post and the others in sequence, but first let me mention = something=20 here that is being missed.</FONT> <BR><BR><FONT face=3Dsans-serif = size=3D2>Gas does=20 not transfer from tissues into arteries or veins, it does so into = capillaries.=20 The artilleries coming from the heart are huge, thick, elastic , pulsing = conduits that get smaller as they branch out until they become = capillaries, and=20 then the return to the heart is through veins which are also thick and = get=20 larger as they combine to return blood to the right side of the = heart.</FONT>=20 <BR><BR><FONT face=3Dsans-serif size=3D2>That blood is then sent to the = lungs, where=20 the massive network of tiny capillary beds located in about 45,000 = square feet=20 of surface area, act as a "filter" for bubbles. The "filtered" and now=20 oxygenated blood which has passed its co2 and other excess gasses to the = lung=20 space, goes back to the heart to be pumper through the system again. The = whole=20 trip takes about two minutes to happen.</FONT> <BR><BR><FONT = face=3Dsans-serif=20 size=3D2>You do not bubble into the arteries. If bubbles get into the = arteries it=20 is because they passed the filter or were "shunted" over through a PFO = in the=20 arterial walls, or because they were momentarily compressed enough = momentarily=20 to get past the lungs and then reexpanded as the pressure dropped prior = to=20 reaching the capillaries, in which case they lodge in the smaller and = smaller=20 vessels and block them. This occurs in bounce diving, as in doing a dive = and=20 then bouncing back down to retrieve something, like a deco bottle. This = is why=20 we do not allow bouncing in the WKPP, and why we require our support = divers to=20 stay out for 4 hours before diving shallow for support.</FONT> = <BR><BR><FONT=20 face=3Dsans-serif size=3D2>* If somebody wants to put that post on here, = go=20 ahead*</FONT> <BR><BR><FONT face=3Dsans-serif size=3D2>Most people get = the greatest=20 rush of bubbles from the tissues into the blood stream upon surfacing = from 20=20 feet or so. This is why we do that differently, post to follow. Most = people tend=20 to bubble for hours after a dive. Most bubbles tend to grow from the = surrounding=20 supply of gas before they get smaller and disappear.</FONT> = <BR><BR><FONT=20 face=3Dsans-serif size=3D2>If the bubbles are in the tissues, yo have = pain. The way=20 to prevent bubbles in the tissues is to properly decompress starting = deep and at=20 a rate that allows the bubbles to escape to the blood stream. Deep this = needs to=20 be done carefully and in solution, shallow you can press the gradient = and allow=20 offgassing in bubble form into the blood stream. The difference is that = if you=20 screw up shallow, you can go back a little and fix it. If it occurs = deep, that=20 makes it impractical and a huge waste of time for nothing. For people = wight=20 cardiac or pulmonary shunts, offgassing in bubble form is super = dangerous. For=20 those without, it is far more efficient. For those with PFO's, the risk = is=20 greatest AFTER they get out of the water for the reasons stated above ( = growth=20 of bubbles and continuation of bubble offgassing)</FONT> <BR><BR><FONT=20 face=3Dsans-serif size=3D2>I think you can see where I am going to tell = you that you=20 need to do your shallowest dives first, do your drills before yo do your = dives,=20 and why you can basically ignore repetitive dives using the correct = deco. You=20 can NOT ignore them with respect to oxygen exposure.</FONT> = <BR><BR><FONT=20 face=3Dsans-serif size=3D2>This post is long enough , basic enough and = preliminary=20 enough. Now we can go on to the whole bit.</FONT> <BR></BODY></HTML> ------=_NextPart_000_0016_01C1AED5.6CE9C010-- -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
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