November 2000

By Ernest Campbell

Did Decompression Sickness Cause My Exhaustion?

On a recent dive trip, I made a dive to 40 feet for 30 minutes, and went to the same depth for the same amount of time on my second dive later that day. The next day I went snorkeling and made a free dive to 20 or 25 feet and forgot to exhale on my way up. I have been feeling tired lately--not extremely tired, but more than normal for me. I also have ringing in my ears, though I always have that. None of my joints ache. Am I overly worried? Could I just be worn out?
via e-mail

Fatigue should be considered when evaluating diving accidents. It is a symptom of decompression illness and often is the only complaint a diver has. Usually, when a diver receives recompression treatment for limb pain, the underlying fatigue disappears along with the pain.

Exhaustion is also a prominent symptom of many other illnesses. Given the dive profile that you describe, your fatigue is most likely not due to decompression sickness. If you continue to have problems, request an exam by a chamber physician and obtain treatment in a chamber. The fatigue might respond to the treatment.

Can DCS Cause Strokes?

A friend of mine suffered some strokes a couple of years after one doctor said she might have decompression sickness. At that time, she was an airline attendant and flew after a dive, supposedly with enough time in between the dive and flying to be safe. A few days after the flight, she experienced some symptoms of DCS. Her physician said she might have DCS, but that it was too late for recompression therapy. She has since had the strokes and had many tests. Some doctors say she has a connective tissue disorder, and others say it is because she got bent, and that she could die suddenly. The tests did find damage to her brain. If she had DCS, could it have caused the air bubbles to constrict blood vessels in the brain, leading to her strokes?
via e-mail

It's improbable that your friend's strokes are related to decompression sickness. The possible relationship to a patent foramen ovale--a condition where blood can flow from the right chamber to the left across the heart without passing through the natural filter of the lungs--might be the reason, but in this case it's impossible to prove. In a diver with a PFO, the bubbles could bypass the lungs and flow directly to the brain, where they could cause what are essentially mini-strokes. Over time, enough of these small strokes could cause neurological or cognitive deficits. If your friend has not been evaluated for an abnormal right-to-left shunt in the heart, then she should consider this. For more information on PFO, go to www.scuba-doc.com/pfo.htm.

Bubbles from a decompression accident don't linger, but are absorbed gradually. Recompression of the bubbles is done because this improves the outcome markedly--even as much as several days later. However, the damage that these bubbles cause with subsequent scarring can lead to residual neurological changes, varying with the part of the brain left scarred. It's impossible to say whether your friend's previous decompression accident or the strokes have caused her difficulties.

Can a Person Recover from Paralysis Caused by DCS?

A friend of mine got decompression sickness. One week after getting bent, after having three recompression sessions, six hours each, he still has no use of his legs. He is paralyzed from the sternum down. Is there any way he will be able to walk again?
via e-mail

A friend of mine got the bends while diving. He is now in a wheelchair. Is this reversible?
via e-mail

The answer in both cases is most likely no. The bends is what divers call decompression sickness. In its worst form it can cause permanent neurological damage to the spinal cord and brain. In the U.S. alone, Divers Alert Network (DAN) reported 590 cases in 1995. Of course, there are many millions of dives made each year by the estimated millions of divers in the U.S.

The condition is prevented by carefully following the rules of diving at all times and is treated by early recompression in a hyperbaric chamber. Treatment is generally continued until there is diminishing or no response to the treatment. Response is highly variable and not readily predictable. Oxygen administration after recompression treatment is helpful in reducing recurrences of DCS. Rehabilitation programs often enable paralyzed patients to return to some level of function. The attending physician should be able to tell you more about your friends' outcomes.

Can I Dive With a Congenital Heart Condition?

I am 12 years old and have a congenital heart blockage. Does this prevent me from getting certified to dive?
via e-mail

Bad news: You probably should not dive. I assume you are referring to "aortic stenosis," a congenital obstruction that prevents blood from getting from the left ventricle of the heart into the aorta. Any degree of this condition, other than extremely mild, is a contraindication for diving because the heart is prevented from pumping blood during exercise, and pulmonary edema and fainting can ensue.

Can I Dive With a Pacemaker?

I was born with a congenital heart defect between the ventricles and the atrium. I now have a pacemaker that regulates my heart at 60 beats per minute at rest. The maximum rate is set at 120 beats per minute, but that rate is uncomfortable for me and produces anxiety. Can I dive? Are there special considerations I should know about?
via e-mail

Generally, people requiring pacemakers should not dive because of their basic heart condition. Occasionally there are individuals with certain arrhythmias who have pacemakers who may dive. If no other heart disease is present, and the pacemaker is tested against pressure up to 130 feet and exercise tolerance is good, you might be able to dive. However, there are pacemakers that increase their rate when pressure is applied to the generator case, resulting in a heart rate inappropriate to the demand.

Unfortunately, it's impossible for me to advise you properly without a cardiologist's evaluation of your condition.

Can I Dive After An Ear Operation?

**I am 37 years old and have been diving for 12 years. I have completed just over 500 dives. Recently, I developed a ringing in my ears that specialists call otosclerosis. This ringing is not related to my diving. Instead, it appears to be a calcium buildup on one of my inner ear bones that is pushing the inner bones against my eardrum. This contact causes constant ringing.

The ear specialist said I could have an operation in which the problem bone and the calcium would be removed and replaced with a plastic bone. Most or all of the ringing would go away, but I'd never be able to dive again since the operation would involve cutting through my eardrum. The risk for further problems once you cut through the eardrum is too great, therefore I'd have to quit diving.

Is this true?**
via e-mail

Otosclerosis is the abnormal growth of bone of the inner ear. This bone prevents structures within the ear from working properly and causes hearing loss and ringing. Otosclerosis usually affects the last bone in the chain, the stapes, which rests in the entrance to the inner ear (the oval window). The abnormal bone fixates the stapes in the oval window and interferes with sound waves passing to the inner ear.

In an operation called a stapedectomy, a surgeon (otolaryngologist or otologist) bypasses the diseased bone with a prosthetic device that allows sound waves to be passed to the inner ear. The problem for divers is that the pressure changes from clearing the middle ear can force the prosthesis through the oval window due to the lack of normal muscular support. This could result in permanent damage to the inner ear.

Unfortunately, I agree with the advice you received from your ear specialist. The risk of injury from pressure changes would be quite high and could end in permanent deafness or severe inner ear damage.

What Do You Know About Star Otic?

I read that Otic Domeboro is the best product for preventing swimmer's ear, but it's expensive and available by prescription only. Solutions containing alcohol are readily available, but irritate my ear. A "home brew" mixture is a possible alternative, but I don't think this a prudent alternative. I did some research and found a product called Star Otic. It is a Modified Burow's Solution (essentially Otic Domeboro) and is available over the counter for about $5. I tried it on a dive trip a few weeks ago, and it worked great. Is it OK to use?
via e-mail

Star Otic is an alcohol-free solution and contains Modified Burow's Solution, a mixture of aluminum acetate, acetic acid and boric acid in a propylene glycol vehicle. Cost is significantly less--$3.79 per 5-ounce bottle--and it's safe to use.

Incidentally, a homemade solution of half vinegar, half peroxide is safe and effective. For more information on ear drops, go to www.scuba-doc.com/otext.htm.

Help! Diving Gives Me Gas

After I dive, I often suffer from large amounts of upper abdominal gas and bloating. Is this normal? Should I eat or avoid eating certain foods prior to or after diving?
via e-mail

I can think of two things that cause gas and bloating in a diver:

• Pressure from your wetsuit can cause gastroesophageal reflux, particularly if the suit fits poorly.

• As you descend, you swallow some air while clearing. This air is not a problem at depth, but when you ascend, it enlarges and can cause pain and bloating.

You might want to try to clear using methods other than swallowing. There are medications that a physician can prescribe designed to help eliminate gas.

To read more on this, go to www.scuba-doc.com/hrtbrn.htm.

Can Contacts Damage My Eyes While Diving?

My dive instructor says that pressure and dry air in a mask can dry out eyes, causing contacts to damage the eye. He says I should get prescription lenses. Is this true?
via e-mail

I'm afraid your dive instructor is wrong. The only real risk you run by wearing contact lenses under your mask is financial: If your mask floods, your tiny, transparent investments can be washed out of your eyes and into the great blue. Whether you decide to use prescription lenses or contacts is a personal preference. If your eyes are stable and your vision is not changing, the prescription lenses may be your best bet in the long run, though a corrective mask is useless before you put it on and after you take it off. With contact lenses, you never lose visual acuity, even on the boat. For more information, go to www.scuba-doc.com/diveye.htm.

Can I Take Allegra and Dive Nitrox?

I occasionally take Allegra for an allergy. Can I take this drug and dive nitrox?
via e-mail

Allegra has none of the effects that mimic adrenaline and is safe to use with nitrox. It reduces the risk of oxygen toxicity, unlike some other allergy medications that may actually increase the risk of oxygen toxicity. Another point: Allegra has fewer sedative side effects than other allergy medications.

What To Do When You Think You Have DCS

Use Oxygen
If you suspect any type of decompression illness, start breathing 100 percent oxygen as soon as possible. Oxygen kits are standard equipment on every reputable dive boat in operation today. Pure oxygen is first aid for any suspected decompression illness because it increases the rate of nitrogen elimination and decreases the size of offending nitrogen bubbles--buying you precious time until you can get medical help.

Call DAN
If you're not sure you have DCS, call DAN's nonemergency number (919-684-2948) to get expert assistance in deciphering your symptoms. DAN has doctors on call 24 hours a day who can help answer questions, as well as ask a few of their own, and arrive at some sort of decision about your complaints.

Diving: Does It Stress the Heart?

Underwater photographs often make diving look as effortless as floating in a pool. But think about what you do when you dive--swimming, walking with heavy gear, climbing ladders and sometimes performing heavy labor. Because exercise causes your body to increase its oxygen and fuel production, exercise taxes your heart and cardiovascular system.

In addition to the physical stress induced by exercise, merely getting into the water up to your neck increases the amount of blood flowing into your heart. Exposure to cold causes vasoconstriction and slows the heart rate. These factors may adversely affect cardiac function and put patients with heart disease at risk for accidents while diving.

Determining how hard your heart can perform may be necessary to find out if you have any limitations due to heart disease. An exercise stress test will reveal whether your heart can pump enough blood to meet maximum needs.

Exercise Stress Testing
Exercise stress testing measures cardiovascular reserve when assessing the heart. Used mainly to detect coronary disease, it also can be used for determining cardiac reserve in divers. A diver should be able to do the test on the treadmill without chest pain, severe shortness of breath or blood pressure changes.

Physical Fitness
What does it mean to be physically fit as a diver? You should be able to swim a reasonable distance with diving gear, without getting too short of breath, and be able to help a buddy who has been injured or requires assistance in returning to the boat. You should carefully plan your dives and avoid situations requiring physical exertion above and beyond your physical capacities.

A moderate exercise program that can be done four or five days a week is adequate for the casual diver. Swimming is great exercise, but jogging, walking, biking or rowing are also good for increasing your pulse rate, breathing rate and oxygen intake.

_Ernest S. Campbell, M.D., FACS, makes his home in Orange Beach, Ala. He is a retired surgeon, avid diver and webmaster of "Diving Medicine Online" (www.scuba-doc.com).

Please send your dive medicine questions to RSD, 6600 Abercorn St., Suite 208, Savannah, GA 31405. Fax: (912) 351-0735. E-mail: [email protected]._