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As I sit writing this, only a few yards away through a brick wall and a foot of steel lie 2 of my patients. They are undergoing a Royal Navy Table 62 recompression. Both have decompression sickness. But what is unique about these two, boyfriend and girlfriend is that it was all so avoidable. Nick and Janet had qualified three months previously and apart from the four open water dives deemed necessary to get a certificate of competence they had done no more. Whilst on holiday last week the opportunity to dive again came up. Both keen to keep their log books ticking over, they went for it. At the dive shop they told the owner that they were inexperienced and asked to do a simple dive. This was no problem apparently as the shop had 2 groups going out, one to a 30 metre [100 foot] max, and the other to only 15 metres [50 feet]. They signed up for the latter. Gearing up, Nick was given a 12litre tank, whilst every one else was given 15 litres including Janet. Nick is over 6 feet tall, Janet, under 5 ½ feet. Down they went off the boat and their group levelled out at the prearranged depth. This is when it went wrong. The Divemaster then proceeded to go after the deeper group and beckoned to his less experienced charges to follow him. They did. They followed him way down to 40 metres[130 feet]. After well over 10 minutes there Nick noticed he was in the red zone on his pressure gauge, less than 50 bar. In his own words " I guess I was narked, though I've never experienced that before. So I panicked, over inflated my BCD and went straight up to the surface" He remembered to exhale, luckily, but managed to break the surface water waist high. Janet was dragged up too and hit the top still clutching Nick's leg. Amazingly neither of them suffered any problems immediately.

But later that day Nick started to get tingling in his arms and also noticed pains in his shoulder joints. He rang the dive shop and told them, but they said it couldn't possibly be a bend as he hadn't been deep enough for long enough. OK he thought, they must be right. He still had the problem 2 days later, and told them again. This time they let him have some oxygen, but for 5 minutes saying that was enough. He flew back home a day after this whereupon everything worsened. And there they both are with about another 3 hours to go on the table. They have both improved already, but through the chamber intercom they've asked myself and the outside attendant whether we want to buy any dive gear.

There are 2 lessons to this tale. Firstly what happened to them both is not isolated, it happens to a diver every day of the year. You are told one profile above water only to have it changed for no reason below. But you follow blindly even when you know it's going well beyond your experience. If you go into a bar and ask for a beer and pay for a beer, what would you do if they give you wine instead. Of course you would refuse and demand what you paid for. But why is it OK in diving to pay to do one thing and get something else. Well the answer is it's not. Nick and Janet should have refused to go deeper and indicated to the DM that 15 metres was where they were staying. Because the results of not trusting your own judgement and blindly following the leader are just a few feet away breathing 100% O2. There are situations where profiles have to change, in event of conditions or emergencies, but that wasn't the case here. Just a misguided shepherd and his flock. So next time you dive remember it's your dollar or baht and make sure you get what you pay for.

The second lesson is equally important. Dive tables are basically guidelines. Calculated by using lean fit US Navy volunteers. You can get decompression sickness even if you dive within the limits. Not very often, but you can. The most important thing as a diving doctor is what are the symptoms. If you are recently out of the water, complaining of tingling, numbness, fatigue or whatever, I don't really care exactly how long you were down or what your maximum depth was, all I want to know is could it be a bend from the symptoms you have. It was obvious Nick was bent from his symptoms and he should have been given oxygen as soon as he called the dive shop later that day. However before we blame the shop for misdiagnosing we need to make sure our own medical house is in order, and from my experience it's not. I have seen the most obvious cases of DCS sent away from the Emergency Departments of hospitals with a handful of paracetamol. One girl had obvious numbness and loss of power in her right arm, but was told that she was being hysterical. Another told that the joint pain in the ankle was probably a sprain, despite it coming on whilst he was lying on a sofa watching TV. Why do so many docs get it wrong? Well here's why. When I trained at med school the sum total of teaching on decompression sickness was 1 hour and that was in my second year of five. I never saw a case until I actually learned to dive myself, and the symptoms you learn about were always the extreme ones of severe crippling joint pain or total paralysis. Never the most common Type 1 symptoms of fatigue, skin rash, numbness, loss of balance or tingling. So if you have any of these sorts of symptoms after diving and are not sure whether it's a bend or not then take yourself to a diving doctor. You wouldn't ask an eye surgeon to fix a hernia and neither would you try to buy pork from a fishmonger as he sells "food". I asked Nick what was at 40 metres anyway. "Nothing" he said "I think the DM was just testing his new computer." Anyone need a cheap BCD?