BENDS EXPLAINED
HOW TO PLAN A SAFE DIVE
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BENDS EXPLAINED, Page 42 Men CASE 2. J.S. WAS SYMPTOMATIC YET HE FLEW AFTER DIVING. J.S. dove Grand Cayman in rough seas using two tanks of compressed air per day to a depth of 110 fsw. He, at the time, was a 30 year old professional, 70 inches tall and weighing 170 pounds, Body Mass Index 24.4 (there is a simple table in the ALMANAC to calculate BMI). He was certified by PADI as an open water diver, a basic certification. He had been diving for two years. He made 13 dives in the past year. He never smoked and had no contributing medical history. At the end of a week of diving, on December, 8 he dove to 100 fsw for 20 minutes (correctly he thought this was a no-decompression dive) and after a 30 minute surface interval he dove 50 fsw for 43 minutes (and incorrectly he thought this too was a no-deco dive). About 15 minutes after diving, he experienced a light-headed feeling that was soon followed by extreme generalized fatigue. Later that night he had pain in his knee. He continued to dive on Dec. 9 and then he flew home-to N.Y.C. That evening he had shoulder, elbow, and knee pain in addition to the light-headed feeling and extreme fatigue. He called DAN on Dec. 10. Was this a non-deserved hit? Calculate his diving on the day of his accident (it was no accident). He was a Repetitive Group D diver which added 14 minutes bottom time to his first dive. Add his times 14+20+43=77 minutes. 100 fsw times the square root of his time 8.8 is 880. Subtract 500 for no-deco dive and divide the remainder by 6=64 minutes of missed decompression. [If you add Residual Nitrogen Time to his second dive the missed decompression gets larger. My method just add the times of the dives plus the Residual Nitrogen Time for the first dive which is typically the deepest dive of the day. The square root of this number multiplied by the deepest depth of the dives gives an index number. The NOAA and 1993 U.S. Navy Air Diving Tables are constructed so a no deco dive has an index number (depth times the square root of the time is 500 for the U.S. Navy Air Diving Table) minus 500 then divide by 6 (an arbitrary number) to get the missed decompression time.] On his third dive on Dec. 9 after his "accident" he missed his decompression because he did not take his RNT into account. The 6th Revision of the U.S. Navy Diving Manual -soon to be revised and a free download-is slightly different. His initial treatment the day he called DAN, Dec., 10, was a U.S. Navy Treatment Table 6 for 284 minutes. His elbow pain was relieved by inflation of a blood pressure cuff at the point of the pain. He got temporary relief and this was repeated while he was under pressure-with success. Two subsequent modified U.S. Navy Treatment Table 5's now called U.S. Navy Treatment Table 9, formerly known as a Kindwall Protocol were administered Dec., 11 at 38 fsw for 93 minutes and Dec., 19 at 40 fsw for 90 minutes because the light-headed feeling returned. After three re-compressions he said that he had no residual symptoms. Comments: SOD (Surface-On-Deck) oxygen breathing should definitely be available for deep (over 80 fsw) repetitive diving. Perhaps he wanted to get the most diving for his dollar by compulsively diving twice a day as deep as he could. Perhaps he enjoyed the mild narcosis. A proper rest between dives includes rehydration and reclining for at least an hour. Tri mix today is readily available and I will add more information on that on my websites. Diving Medicine for Scuba Divers is also a free download, see SCUBADIVECHAMBER.COM for a link.
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About the Book
Details about many of the divers that I evaluated are included with comments on the way their dives got them into trouble and the chamber at City Island, NAHC. I discuss their treatment profiles and the results of their treatment. It presents a larger series of bent divers than any I am aware of. Should you find another comparable series contact me at avoidaccidents@ymail.com. Ideas about bends have changed from the concept that a bubble formed in the nervous system because of a rapid ascent or the joint by cavitation-negative pressure. Rapid ascent or joint motion caused the culprit to appear and pressure would make the bubble go away. Now we are focused on treating tissue damage with oxygen. But, we are still using pressure and oxygen to increase the partial pressure of oxygen in the affected tissue. The treatment of choice is the 5 hour long U.S. Navy Treatment Table 6 which washes out the nitrogen in the tissue and washes in the oxygen. Careful understanding of how my patients got bent and how they responded should make any diver more cautious regarding repetitive diving and a multi-day series of dives. Pressure at the deepest part of the dive washes in the nitrogen over time. Fatty tissue, that includes the central nervous system and peripheral nerves, absorbs more nitrogen than watery tissues such as muscle. Shaping-up to dive includes weight loss, abstinence during the duration of the series of dives, and improving lung function. Physical conditioning prevents tachycardia, a rapid heart beat, during exertion. A program of regular exercise two or three times a week prevents early fatigue during prolonged exertion, or increases stamina. Exercise such as walking 20 or more minutes a day for several weeks before diving is as important as paying for the trip. Swimming accustoms one to buoyancy, relaxing in the water, and adjusting temperature regulating reflexes such as vaso-constriction in the skin on immersion. Dive accidents sometimes do not have a treatable solution. Most "accidents" resolve after one re-compression breathing oxygen under pressure. Many patients were treated multiple times, and some did not get complete relief of their symptoms and/or neurological findings. Immediate therapy traditionally is in-water re-compression which has its drawbacks. It is difficult to administer and hypothermia, fatigue, and drowning are risks. Surface-On-Deck oxygen breathing from a face-mask or immediate re-compression in a chamber are always effective treatments. Transport to a facility has logistical problems and the destination chamber may not be functional when it is needed. The U.S. Navy Diving Manual Rev.6 Vol. 5 20-4.4.2.1 has procedures for In-Water Re-compression using AIR, 20-4.4.2.2 In-Water Re-compression Using Oxygen. Both sections advise going to 30 fsw and additional instructions for decompressing. If oxygen is used and the decompression has been completed then 3 hours of oxygen breathing is the procedure. One cylinder of oxygen and a face mask are good for one diver for 3 hours. Where are the other cylinders for other divers? The book is about the chamber that I personally operated and staffed. I was almost continually available. The number of bent divers that I treated, not all are included in the book because they were routine, speaks for itself. AAA, Avoid An Accident-Plan Safe Dives.
About the Author
New York City public schools: The William T. Sherman school, The Joan of Arc Jr. H.S., and The Bronx H.S. of Science. were all favorites of mine. After receiving my B.A. from Columbia College in N.Y.C. I received my M.D. from the University of Louisville School of Medicine. After a Straight Surgical Internship and a year of Neurological Surgery at N.Y.'s Mt. Sinai Hospital, under Dr. Leonard I. Malis, I served in the USNR as a General Medcal Officer and was promoted to Lt. Commander; A decade later, I took a tour in Japan in the U.S. Navy. I was a Fellow at the Cleveland Clinic in Neurology, Neurosurgery and Internal Medicine. After being part of the Peachtree Surgical Associates I was a Medical Staff Physician at V.AH. Tuskeegee. I was a "Doc in the Box" in Jacksonville, FL before moving back to NY. I completed a year of Internal Medicine Residency at Brookdale Medical Center and less than a year of a Nephrology Fellowship at St. Lukes Hospital both in N.Y.C. Andre Galerne appointed me a Consultant to the North American Hyperbaric Center in 1988. At NAHC, in the Bronx, I treated SCUBA diving accidents and a variety of medical conditions in the Iglu which is 20 feet tall with a wet pot in the lower half. It is 10 feet diameter. I have been an inside tender with as many as nine patients at once. The Diver's Alert Network referred all of the patients that I treated for bends. Local hospitals referred various patients with osteo-radionecrosis of the mandible and complications from diabetes mellitus (psoas abscess, diabetic foot, mucormycois and osteomyelitis of the foot). Andre suggested that having an unusual opportunity to use the largest hyperbaric chamber complex in the western hemisphere, I should develop a research project. I reviewed the medical magazines at the library of Mt Sinai Hospital and noticed a Mountain Bag engineered by Igor Gammow and manufactured by E. I. Dupont. It was, as you would expect, a nylon bag with a zipper inflated with a wooden bellows called a foot pump. At two psi gage it would simulate a 10,000 foot descent down a mountain. I persuaded Nazim, the machinist at IUC, to fabricate on his lathe some pass-throughs. I succeded in bringing oxygen into the chamber to a face mask and I utilized the 2 psig blow-off valve to vent the excess oxygen. HTI had purchased the patent for the Gammow Mountain Bag and with my help converted it into a portable hyperbaric chamber. Today the derivitive of that chamber is the most popular portable chamber on the planet (the Solace hyperbaric chamber (distributed by OxyHealth). My intention is to pay tribute to Andre by continuing to serve the diving community with my outlook on diving accidents. As most divers, I have had brushes with bends myself. A little insight may help divers recognize bends early and perhaps avoid more serious episodes. For example, if on the third day diving on air to 80-100 fsw one starts vomiting after a light breakfast, it might be a good idea not to dive that day. WWW,Scubadivechamber.com has more information. I relocated to Kissimmee, FL to enjoy a more relaxed retirement and raise Lilian who attends Osceola County School for the Arts, in a country environment. However Poinciana where I live has grown, almost into a city. I enjoy movies, outdoor swimming, and my wife's cooking. Her specialties are oatmeal cookies and Chinese food.