Rescued PA Miners Recount Ordeal (***PICTURES***)

Thanks!

While the folloing info is from a report concerned with the gas mixtures used by deep divers, it is relevant for the general (and as yet poorly understood) long term effects of depressurizations.

(Source: Physiology and Physics of Helium, Robert Palmer, European Training Director, Technical Diving International)

LONG TERM EFFECTS OF DEEP DIVING
There are several potential long term effects of deep diving of which the recreational or professional trimix diver should be aware. Many of these are still postulated, and remain formally unproven, but enough evidence exists to suggest that damage may be done to the diver's body by a variety of pressure-related processes.
Capillary Atrophication and Aseptic Bone Necrosis
Perhaps the best known of the long term problems is Aseptic Bone Necrosis, where the destruction of capillaries within bone tissues causes local necrosis of the bone - that is, the bone tissue effectively dies and falls apart. Traditionally, the long bones (thighs, shins, arms) were most at risk, with the heads of joints at shoulder and pelvis especially at risk. At one time this was though to occur primarily in commercial saturation divers, but it has been fairly commonly recorded in recreational divers, where there is some evidence to suggest that it affects the center sections of bones rather than the ends. What causes it is not entirely known, other than it is associated with capillary Atrophication. Such Atrophication may be associated with rapid pressurization and/or depressurization, where different tissues within the bloodstream on and offgas at different rates. This means that certain of the blood's constituent tissues may at different times during descent or ascent act as effective dams within the smallest capillary beds, creating tiny local embolisms or micro-Atrophication. Though this is perhaps most crucial in bones, capillary beds also exist in other vital areas of the body such as the brain, soft tissues such as the liver, kidneys, eyes, etc. At present, alterations to capillary bed structure in these other tissues are best described as "change" rather than damage, until more research is done on both cause and effect.
Research on Aseptic Bone Necrosis shows that affects approximately 5% of divers (both recreational and commercial) to some degree or another. Deep mixed gas diving may be one contributory factor, as may rapid pressurization/ depressurization, but the increase in symptoms evinced in recreational divers who do not undertake such practices suggests that the problem still warrants further research before too many conclusions can be drawn.
BUBBLE FORMATION
Micro-bubbles forming during decompression, though not creating any formal symptoms of decompression illness, may result in long term CNS damage to the spinal cord. Postmortems in divers who have not reported any symptoms of DCI during life have still been found to have significant damage to the spinal cord and central nervous system.
Those who have had formal decompression events may have significantly greater long term problems, especially divers who have suffered multiple type II bends.
Such "invisible damage" may or may not be associated with deep diving. It is possible that now out-dated diving practices may have contributed to these (e.g. faster ascent rates) and that individual physiology may also play a part. To a degree, all life activity, above or below water, contributes to the eventual long term decay of the body, and the older we get the more damage has been picked up along the way. It is possible to overreact to physiological "possibilities", and it must also be remembered that diving of any sort has a very low incidence of long term serious physiological damage per individual diver when compared with other activities.
However, when formal damage does occur it should be treated seriously. Getting decompression illness may result in small localized damage or it may contribute to longer term damage, such as possible brain lesions, which may in turn create later problems from reduced mental or physical function to premature senility. Divers of all sorts, and mixed gas divers in particular, should be aware of current research in diving medicine, and should keep themselves up to date with changes in our knowledge and understanding of diving medicine.

Bumpin' for answered prayers . . .

Hooary and huzzah!

"So how common are hyperbaric chambers in trauma centers?"

Hopkins in Baltimore had two of them in 1983. One reason they told me was because drugs have an easier time getting into the bloodstream.
I got into a nasty accident on a bike and gotta helicopter ride to shock-trauma that year.
I needed a few operations to make things work again and I woke from most of those in the hyperbaric. I even had some hyperbaric therapy which was basically sitting in there for 2-4 hrs a day.
Seemed to work, I can walk again.

Seems to me that de-pressurization was not necessary because the conditions that necessitate it WERE NOT PRESENT. To wit, at an UNDERWATER depth of 250 feet below the surface, the (atmospheric) pressure on the body and the bloodstream is VERY HIGH. At 250 feet below the surface of the earth, with ventilation shafts to the surface, THE ATMOSPHERIC PRESSURE IS NEARLY IDENTICAL TO THAT ON THE SURFACE. Pretty basic stuff.

I seem to rememeber hearing that the space was pressurized -- it held the water at bay -- and that the ventilation and escape shafts were pressure sealed.

Initailly, they had to pump air down into the chamber at a pressure higher than atmospheric in order to maintain a "bubble" of air. However, as the water was pumped out of the mine, the water level dropped at about 1 foot per hour, which is close to the normal decompression schedule. And by the time of rescue, they were back at atmospheric pressure.

IOW, draining the water decompressed the miners.

Thanks for that explanation.