Scuba Diving and Decompression Sickness - A Brush With The Bends

Many activities in life are inherently risky and scuba diving is no exception. While serious injuries and fatalities are rare, they tend to be newsworthy. Many times the risk is blown out of proportion based on individual perception. For example, while there is a risk of running out of air and drowning, modern equipment, training and techniques should reduce this risk almost to nonexistent. When it does occur, it can usually be traced to an error in diver judgment. Another overhyped risk is that of shark attack. Sensationalized reports and sweeps week cable programming make sharks out to be nonstop eating machines always looking for divers to snack on, and this just isn't the case. However, there are very real risks involved, and proper education and information are vital to protect oneself.

One often misunderstood risk is the risk of decompression sickness. Commonly referred to as 'the bends', this condition arises from breathing air under pressure, specifically the nitrogen component. Under pressure, the nitrogen in air is absorbed into the bloodstream and tissues. While our bodies burn oxygen, as an inert gas the nitrogen stays in solution in our bodies until the pressure is relieved, which occurs as a diver surfaces. This is why divers surface slowly, and a 'safety stop' at a depth of about 15 feet for at least 3 minutes is recommended, to allow the nitrogen to come out of solution and be expelled by the lungs.

Even many non-divers are at least somewhat aware of the danger of surfacing too rapidly. Since the nitrogen does not have the time to be released, it comes rapidly out of solution inside the tissues and joints, causing a great deal of pain and other symptoms. However, many people are not aware that decompression sickness - or trapped nitrogen - can occur to any diver at any time, even when all safety guidelines have been followed. During a recent trip to Cozumel, I experienced this firsthand. Although all guidelines were followed, I developed decompression sickness and had to be treated in a hyperbaric chamber.

In February of 2009, my wife and I took a scuba trip to Cozumel. During that trip, we dove over 20 times, at all different depths, with no ill effects. Since then, I have also taken advanced training and been diving in Beaver Lake, Arkansas up to a depth of 70 feet, again without incident. In November of 2009, though, I developed symptoms after the first two dives of another trip to Cozumel, both at 45 feet or less. Missing the significance of the symptoms, we dove again the following day, this time to a maximum depth of 85 feet, with worse symptoms as the result.

A little background is in order. About a month before the trip, I accidently came into contact with some poison ivy and was prescribed Prednisone to combat the reaction and to speed healing. Normally, when I am exposed to poison ivy, I break out in hives on my arms, thighs and abdomen. I finished the course of steroids, and was warned to avoid too much sun exposure, as Prednisone can make you sun sensitive. I did my best to follow this direction, but it is virtually impossible to avoid the sun completely out on the ocean.

After the first day of shallow diving, I developed what looked like an allergic reaction on my abdomen about 2 hours after we completed our last dive. It looked exactly like the hives I normally get after poison ivy exposure, and itched just the same. I thought that it was a reaction from the Prednisone and sun exposure, so I took some antihistamines and laid down for about an hour, after which I felt pretty much normal. I mentioned this to the group of divers we were travelling with, which included our local dive shop owner, his wife (a nurse) and one of the dive shop instructors who was also on the trip. All of them have hundreds of dives, and not one connected these symptoms with decompression sickness. As we had all been diving in the same group, they all knew that we had not exceeded any safety guidelines, and had, in fact, been extra conservative as we had four first-timers with us. Additionally, none of them had ever known anyone who developed decompression sickness.

Since the symptoms had abated, I went diving the next day, to deeper depths this time, with no apparent difficulty. About one hour after the last dive, the 'rash' reappeared, accompanied by other symptoms. These included abdominal swelling, a bright red cast to my abdomen, severe itching and fatigue. Once again attributing this to sun sensitivity, I again treated with an antihistamine, and ended up sleeping virtually the entire afternoon. During the night I experienced random pain in my arms and legs, and the next morning I had dizziness and a headache. After consulting with the local dive operator, I was referred to the local hyperbaric medicine center.

It took the doctor about two minutes to conclude I had skin bends - decompression sickness involving nitrogen trapped in the skin and fatty tissues of my body. After a few more tests they also determined that the nitrogen had entered and affected my nervous system. I was immediately placed in the hyperbaric chamber for four hours and forty-five minutes, and had to follow up with three more days of two-and-a-half hour treatments. Finally, a week later, I was released to fly back home.

Everyone that I talked to, from the dive shop owner we were travelling with to the local dive operator tried to determine what I had done wrong, all to no avail. We had stayed well within the guidelines, to the point of being extra conservative on ascent rate and doing extra long safety stops. In talking with the doctors, they indicated that, as an extremely popular dive destination, Cozumel has about 120 cases of decompression sickness per year, on average. That sounds like a lot, until you realize that they average about 2,000 divers per day, each making 2 or 3 dives. Of those who develop decompression sickness, more than 90% have no identifiable cause, like mine.

There are a number of risk factors, but none of them seem to fit my circumstances. I am above my ideal weight, but we had heavier divers with us. I wasn't the oldest of the group. I didn't have any recent injuries, and one diver who had quadruple bypass surgery this year dove without problems. I wasn't noticeably dehydrated. I just happened to be the one whose body didn't release the trapped nitrogen.

There are lessons to be learned here, though. As all of the literature states, decompression sickness can hit any diver, at any experience level, at any time. No one is exempt, and there isn't always an identifiable cause. Also, if you don't feel 100% right after any dive or series of dives, don't brush it off. Get checked out. By not going to the doctor immediately, and diving again the next day, I worsened the effects and prolonged the treatment necessary. Also, educate yourself to all of the possible symptoms, and don't try to look for other causes.

At the end of the treatment, I was advised to be on very limited activity for two weeks and absolutely no thought of diving for six months. At that time, I will need to see a doctor who specializes in diver evaluation to get cleared again for diving. Between now and then, I'll have a chance to lose some of the extra weight, work on my cardiovascular conditioning and do some extra research on preventing a repeat. While I have every hope and intention of diving again, I will definitely be more aware of the preventative measures, as well as possible symptoms in both myself and others. Hopefully, this experience will mean no one else has to go through what I had to because of misidentifying the underlying cause of my symptoms.