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Well, I had the opportunity to attend the Dive Philadelphia show this last weekend. All I can say is "Very Impressive!". Congratulations to Dr. Jolie Bookspan, et. al. for putting together a first rate event. The show was on Saturday, October 15 and Sunday, October 16. There were PA area and local dive clubs and shops represented, as well as operations from other dive meccas in NC and FL. There were a few vendors and manufacturers present, Zeagle sticks in my mind. Nice stuff. Both days offered free (after the $8.00 show admission) seminars on topics that ranged from northeast wreck diving to basic photography and dive computers. I particularly enjoyed seminars on "Equipment Modification for Wreck Diving" by John Comly and "Submerged Rescue Equipment" by Lipschultz of the Telford Dive Unit. I came away from the session with Comly with no small number of ideas on equipment modifications to make. It was also interesting to listen to Lipschultz talk about diving the Mark 5 and Mark 12 hard hats. There was also the part about diving in substances other than water - like the by-product tank at a slaughter house. (_YUCK_ 8-*) I have saved the best for last. I attended the UHMS symposium that ran all day Saturday. The topic was the "Medicine and Physiology of Diving". Dr. Bookspan brought in several speakers, each with remarkable credentials, to speak on various aspects of the effects of the diving environment on the body. Together, the presenters gave a startling view of exactly what diving does to the body. Now, I am not a doctor but I am smart enough to know that Aseptic Bone Necrosis is not a good thing! The first speaker was Dr. Fred Bove. Dr. Bove spoke on the realities of diving with such maladies as asthma, epilepsy, heart disease, lung disease and diabetes. A common thread throughout his presentation was that the existence of some conditions should not be an automatic disqualification for diving. For example, a single incidence of juvenile epilepsy brought on by high fever or head trauma. This kind of episode is caused by a short- lived event and often has no long-term consequences. Currently, most dive shops and instructors will not allow you to dive if you have ever had an episode for any reason. Dr. Bove indicated this kind of knee-jerk reaction to something in a persons medical history is inappropriate. Instead, he advocates a personalized approach for each diver. For instance, if the diver had only the one episode, is medication free and shows no abnormality during testing then there is no reason why the individual should not be allowed to dive. He described several shades of grey where there could be a system of informed consent or even outright denial when warranted. The next speaker was Dr. Jim Clark. Dr. Clark spoke on O2 toxicity and its effect on the body. He gave results on studies performed by himself and others. Much data was presented from the book "Oxygen and the Diver" by Donald. An interesting point he made was that if you profile the sensitivity of the entire diving population to a single dose of O2, it closely matches the sensitivity profile of a single diver over multiple exposures. He also pointed out that simple immersion in water markedly increases susectibility to O@ toxicity. The exact mechanism for this effect is still unknown. Following this session was Dr. Maurice Cross. What a delightful speaker. His presentation was on the neurological effects of deep diving. Actually, he touched on several organs, including bone, brain, spine and eye. Part of his job is to autopsy divers. He presented evidence of damage done to various systems long before full-blown DCS is evident, much of it quite startling. Images of dead nerve cells, fluid-filled gaps around blood vessels (lacunae?), loss of capillary density and pigment epithelial lesions in the eye and other good stuff. And all this without a single symptom. Kinda sobering. Dr. Owen Oneill was up next to talk about the "Beneath the Sea" medical chamber at St. Agnes hospital at the New York Medical College. This facility is staffed by divers, for divers and is DAN listed. He provided a brief overview of the mission of BTS, which includes 1)representing every segment of the diving industry - medical, retailers, agencies, captains, clubs, technical divers, sport divers, commercial divers, etc, 2) support divers needs - education, safety, reassurance, treatment 3) national hyperbaric certification, 4) diving referrals and 5) divers exams. They currently have a monoplace chamber, but will complete an upgrade to a multi-place during the first quarter of 1995. Dr. Lawrence Martin spoke on asthma and the diver. Dr. Martin touched on the various medications used by asthmatics and the effect on the diver. He went on to address whether the label of being an asthmatic or personal status should be used to determine fitness for diving. He went on to quote various studies performed by Farrell/Granville, Skin Diver Magazine and DAN. Studies indicate that 1)yes, asthmatics do dive and 2) no, they do not seem to be at any greater risk. Dr. Lawrence emphasized that these studies were in no way conclusive, either pro or con the asthmatic diver. On another note, 1,183 autopsies of divers revealed no asthma related deaths. They were almost always out-of-control or out-of-air problems. Interestingly, Australian and New Zeland studies show that 8% of 124 diver fatalities involved asthmatic divers. Medical researchers are currently investigating this. Dr. Lawrence continued to say that we cannot infer that diving is safe for asthmatics. Obese divers and divers who smoke are similarly at increased risk. In his opinion, if there is no evident impairment in spirometry and there have not been any recent asthmatic episodes, then there is no reason why a well-informed person cannot dive. Dr. Thomas Doubt spoke on the effects of cold on the diver. Dr. Doubt seemed to relish in the obvious (and so he said during his presentation). He observed that "... when you dive in cold water, you get cold.". Okay, I'll buy that. He presented warmth as a combination of thermal balance and exercise efficiency. Basically, the more you work, the more heat you produce and the less heat you lose the more you keep. Okay, I can follow this. Then he started showing graphs of exercise rate verses heat loss verses time and I got completely confused. Evidently, the warming from exercise lasts only for a while since muscle action pumps more blood which drains heat away from the body. He further presented evidence that it is not really possible to insulate extremities like the hands from cold water and still be able to use them. Dr. Doubt also talked about "non- freezing cold injury" which permanently sensitizes a part of the body to cold. Once sensitized, the body will shut down blood flow at temperatures much warmer than the temperature that caused the injury. He closed his presentation by speaking on the synergistic effects of cold and narcosis. Dr. Tom Schaffer was the last speaker. His topic was liquid breathing. He talked of early efforts to use hyperbarically treated saline to ventilate test animals. He only briefly spoke of the successes and problems. Suffice it to say that there were some problems. Technology evolved a liquid version of teflon called a perfloric hydrocarbon. These substances are purely synthetic in nature, are chemically inert, radio opaque, odorless, tasteless and non-bioreactive. PFC's have been used for several years as a blood substitute and carry more O2 and CO2 than blood. In tests with mice breathing PFC's, they survived a trip to 1,000 feet for 10 minutes without decompression. In the movie "The Abyss", the mouse really was breathing the liquid. It is interesting to note that the human actors were not. The PFC's are about twice as dense as water, so respiration can be difficult. On the positive side, the lungs can be completely inflated with less pressure using PFC's instead of air. It also has the benefit of not washing out the surfactants that allow our lungs to inflate with air. Currently, there is experimental use of PFC's in patients with chronic and severe lung impairment and is used for pre-mature infants as well as adults. The study is still in the "do no harm" phase and has been very successful. Well, I am sorry this post got so long but there was so much information presented. Rest assured, I could have written much more. I do not pretend to understand a lot of what was said during this seminar. Indeed, most of the questions were asked by other medical professionals. But I did get a glimmer of understanding that water is not our natural environment. Not only must we learn to continuously adapt, we must adapt to continuous learning. Only then can we truly be at ease in our planet ocean. :~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~:~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~: :Patrick Murphy : murphy@un*.sl*.un*.co* : :Unisys, Government Systems Division :"With their absence, the calm waters, : :McLean, VA :having no memories, no wonder, closed : :(703) 847-2545 :over the spaces they had just occupied: : Opinions expressed are mine alone :as if they had never been there." : ~~~~~~~~~~~~~~~~~~~The score: Opinions-3 A**holes-1~~~~~~~John E Conn~~~~~~~
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