Asthma

Asthma and Diving
I have asthma, and use a bronchodilator before diving. I experience exercise-induced asthma about once every two years, if that, and have had no problems in 40 dives. I lied to get certified, but now I wonder: How much danger am I in?

via email
Telluride, Colo.

When it was suggested that the dive community reconsider its stance on asthma and diving at Divers Alert Network's 26th diving accident and hyperbaric medicine course in May 1995, a hot debate ensued. Asthmatics have bronchial airway obstruction, some more than others. If you remember your diving physics when you were certified, you know that Boyle's law is operative; as the depth and pressure change the volume of an air-filled space has to change (it gets smaller as you descend, larger as you ascend). While breathing compressed air, an asthmatic with obstructed airways can suffer pulmonary barotrauma or a burst lung on ascent. This can lead to arterial gas embolism with devastating brain and heart damage, possibly death (see: www.scuba-doc.com/asthma.htm).

The recommendations that you read on my web page come from the Undersea and Hyperbaric Medical Society's workshop on asthma. I believe that they are conservative and for safety's sake, should be used.

Larry Martin, M.D., offers the following advisory: "A history of bronchial asthma is disqualifying if there have been any attacks within two years, if medication is needed for control, or if bronchospasm has ever been associated with exertion or inhalation of cold air."

It's always a mistake to omit information from your certifying agency and your dive instructor. These rules and guidelines are placed there for your protection (and the agency's). It doesn't mean that they are fixed in cement and cannot be altered if it can be shown that you are not in any danger. It would seem that with 40 dives that you have pretty much found out that it was OK for you to dive safely (given no out-of-air situations). I recommend that you get your lungs checked out carefully before resumption of diving—mainly to rule out terminal airway disease. Possibly a spiral CT scan or a methacholine provocative test would be beneficial in determining any obstructive manifestations.

What does all of this mean to asthmatics who dive, or want to start? Hopefully, the changing perception of asthma and diving will encourage more asthmatics to seek appropriate medical clearance for diving from a doctor with experience in dive medicine. This should result in the screening out of those asthmatics who should not dive under any circumstances, while allowing proper instruction and education of the rest.

Will Asthma Prevent Me from Becoming a Divemaster?
I am going to enroll in a divemaster course, but I have asthma. Could this be a problem?

via e-mail

You shouldn't have any problems tackling divemaster-level training if you have reached the rescue level without asthma problems. However, there may be restrictions imposed by your certifying agency. Historically, asthma has been an absolute contraindication to diving. Diving physicians have felt that the risk for developing arterial gas embolisms is high and that asthmatics should not be permitted to dive.

However, the Undersea and Hyperbaric Medical Society decided that asthma should no longer be considered an absolute contraindication to diving. Rather, divers must be made aware of the risk factors. The following recommendations were made:

    * Exercise- or cold-induced asthmatics should not dive.
    * Asthmatics requiring chronic medications (a bronchodilator within 48 hours of the dive) should not dive.
    * Mild to moderate asthmatics with normal screening spirometry can be considered candidates for diving.
* If an asthmatic has an attack, screening spirometry should be done, and the individual should not dive until his airway function returns to normal.

On the other hand, as in your case, many asthmatics can dive safely. It would seem that some of the old safety concerns have been overstated, and if your physician feels that you can dive, you will probably get along just fine. Based on the latest medical data, the YMCA protocols for asthmatics seem to be the most reasonable (www.ymcascuba.org/ymcascub/asthmatc.html). It isn't wise to dive if you can't meet these standards.

via email

Depending upon what you mean by "bad" air, the answer is you probably won't get bacterial respiratory infections. Bad air is thought of as having been contaminated by hydrocarbons from a bad filter, or carbon monoxide from a faulty motor. Even "bad" air is pressurized and it is improbable that it would contain bacterial pathogens. It would be more likely that such an infection would be contracted from a focus of infection in your own upper respiratory passages—such as a nasal, sinus or throat infection.

This having been said, however, respiratory infections of various types can be contracted from poorly cleansed and decontaminated gear. Bacterial, fungal and possibly some viral infections can be transmitted from tubing, regulators and mouthpieces.

For more information, go to:
www.scuba-doc.com/distrans.htm

       Is it better to use an asthma inhalator before diving or not use it at all? I read that asthma
       sprays can cause air bubbles to go from veins to the arteries and could cause embolisms.

                                                                via e-mail

  Asthma sprays do not cause air to move from the veins into the arterial circulation. And, in fact, sprays
  would be beneficial in opening up any blockage of the airways and in the process would decrease your
  chances of having pulmonary barotrauma and gas embolism (air into the arterial circulation).

       Q: My doctor says I need total knee replacement. How will this affect my diving after I've
       undergone rehab?

                                                                      via e-mail

       A: You should be able to return to diving after complete rehabilitation from your joint replacement.
       This would require a release from your surgeon for complete weight-bearing and physical rehab of
       the muscles with good joint motion.

       The joint replacement would not be affected by pressure, depth or gases since it is solid and
       contains no air spaces. Whether or not the scarring and surgical changes would tend to be a site for
       nitrogen accumulation due to altered blood supply is debatable. Other good advice would be to
       remove your gear in the water and ask for help on climbing into the boat. Conservative diving would
       also seem appropriate.

  I recently strained my leg. I'm supposed to go diving in a couple of days. Should I go?

                                                                     via e-mail

  Leg strains vary in severity and often are associated with blood clots. Some experts believe that there is
  an increased risk of bubble formation in regions of tissue where there has been some disruption of blood
  supply. Others say that leg strains generally don't impose any restrictions on diving. A severe strain could
  sideline you for several months if there are any blood clots. Check with your physician to make sure your
  strain is a fairly mild one.

  There are a couple of other factors to consider:

       Heavy scuba gear places significant strain on a diver's legs. Getting back into the boat might be a
       problem. Ask the divemaster if you can remove your gear in the water and hand it to a crew
       member.
       There is loss of muscle strength and sometimes actual muscle atrophy with a strain, which can
       affect your mobility in the water. Make sure you can fin easily in a pool before going diving. 

Does Scoliosis Affect My Ability to Dive?

       What can you tell me about scoliosis and how it may affect diving?

                                                                via e-mail

  Probably the main concern with diving with scoliosis is the possibility of decreased pulmonary function.
  Scoliosis varies considerably in the extent of the curvature. Some cases are so severe that the chest
  cavity is distorted and the affected person can have abnormal lung function. This would need to be
  assessed carefully to be sure that you don't have any airway obstruction that could possibly lead to
  barotrauma or a "burst lung."

  Another concern would be possible injury to the spine from lifting heavy weights and tanks. Proper gear
  fit, degree of physical capacity and cardiac reserve (the ability of the heart to handle stressful situations)
  might also play a part in your decision to dive.

  You will likely have more difficulty with gearing up, entries and exits, but this difficulty disappears in the
  relatively gravity-free environment of the sea. The advice of your personal physician should be sought
  with these factors in mind. 

  Can a Fracture Preclude Diving?

       Two years ago, my 20-year-old son broke his elbow in a skiing accident. He had surgery,
       and a small metal bar and screws were used to repair the broken bone. The bone has
       healed and he has no problems with his arm. The metal appliances are still in place.

       He is now interested in pursuing a career in commercial diving and has been asked to
       provide an X-ray of his arm before acceptance into the training facility. Could there be a
       problem with this injury and his choice of career?

                                                                via e-mail

  Whether the site of a fracture is a starting point for bubble formation because of changes in blood flow
  has been the subject of medical debate. There are no consistent studies that show that this assertion is
  valid. There is no good evidence that surgery, fractures or other injury increases the incidence of DCS in
  the injured area. Your son's elbow, even with a metal plate and screws, should not be affected
  disproportionately by the diving environment.

  The agency may be requiring an X-ray to have a baseline for comparison later, should the need arise.
  They may be using some guidelines that they have set up for the protection of the diver (and the agency
  itself).

  If his fracture has completely healed to the satisfaction of his doctor and he has rehabilitated his elbow
  adequately, your son should be able to dive without difficulty.

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.

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.

When we returned to the boat, my son's elbow pain had stopped and didn't return. Is it possible he was slightly bent on his first dive, and that he "decompressed" on the second dive? Also, is there anything about a growing child's physiology that would predispose him to DCS?

via e-mail

It is entirely possible that your child had bubbles in his elbow, particularly if there was no trauma or previous history of arthritis. Joint pain from DCS would improve with recompression but would most likely have returned and worsened after the ascent from the second dive. This is not something you can prove, although an MRI of the elbow might be good to have in case of further difficulty.

There are issues to consider with children diving, such as diving's potential effects on lung, bone and other developing tissue. Children divers should stick to dive profiles that minimize their DCS risk to eliminate possible injury to growing tissues, such as the growth plates of bones. There are no studies that indicate that these growth plates (epiphyseal plates) are a particular problem—just suspicion that an area of increased vascularity might be more susceptible to bubbles. Since the damage that can be done to bone is directly proportional to the length of time at depth, time and depth should be restricted in the growing teenager. A teenager's ascent rates and safety stops should be carefully monitored.

Also of concern is patent foramen ovale, which can allow venous bubbles in the right side of the circulation to cross over into the arterial side and cause clinical bends or arterial gas embolism. It is known that the rate of closure of a patent foramen ovale in the heart is highly variable and in some children, it will not have closed by age 7. This is something that your pediatrician can check.

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.

via e-mail

There is no evidence that surgery, fractures or other injury increases the incidence of decompression in an area. Risks of DCS are often predicated on unproven assumptions of bubble accumulation at sites of altered blood flow, either increased or decreased.

You will likely have more difficulty than usual with gearing up and doing sea entries and exits, but this disappears after you are in the relatively gravity-free environment of the sea.

If your surgeries have completely healed to the satisfaction of your surgeon—then you should be able to dive without difficulty.

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.

In the last few years, my back has been "going out," landing me in bed for about two days. The last two episodes occurred on a dive boat, just after a dive. Both times, I felt a "pop" in my lower back. I am 39 and in good health. I work out three to five days a week, riding a stationary bike and lifting weights.

An orthopedic specialist says I have some arthritis in my right hip joint. He is concerned that the chronic pain is because of a diving-related injury. He said I might have a form of bends, and each subsequent dive is aggravating the injury further. I have an MRI scheduled in a month to see if bubbles are concentrated in my lower back area. What do you think?

via e-mail

I think this is a mechanical back problem unrelated to diving. You need to be sure that the arthritis of the right hip is not dysbaric osteonecrosis. A thorough examination by a neurologist could settle this once and for all.
Since you describe your back "going out" with a pop, I don't think your back problem has been caused by a decompression accident, especially since you don't mention any neurological symptoms. I suspect chronic lumbosacral strain or arthritis. The orthopedist is correct in noting that your hip problem could be due to diving since there's the possibility of dysbaric osteonecrosis in divers who have made poorly controlled deep dives. This would show up on an X-ray, and should be relatively easy to diagnose.

Bubbles wouldn't show up in diagnostic testing as they don't hang around very long and are absorbed by the body. Their "footprints" remain as scars from the resulting tissue damage and as inflammation, which occurs with a decompression accident. Subsequent diving does seem to concentrate new bubbles in or around the areas of previous damage. The MRI might show damaged areas, but you would surely have had some neurological indication of this.

                                                                via e-mail

  Joint pain that is due to a decompression accident is caused by several things:

       the pressure caused by the actual presence of bubbles in the tissues around the joint

       the production of chemicals called kinins that cause an inflammatory response similar to arthritis

       tissue that is damaged when clotting and other protective systems are triggered, resulting in pain,
       increased blood flow and swelling.

  Compression, such as a blood pressure cuff or a tightly wound Ace bandage, usually causes an
  immediate decrease in pain. However, if left untreated, the pain has a greater chance of being caused by
  the effect of kinins, swelling and loss of blood flow. In this case, the pain might last for an indeterminate
  period—sometimes for weeks or longer. This untreated damage might also tend to make the diver more
  susceptible to subsequent episodes of decompression illness.

  Bubbles have been found in divers even after what was thought to have been successful treatment of
  DCS. Consequently, it would be wise to recompress every case of DCS using oxygen alternated with air
  (the oxygen replaces the nitrogen and is metabolized rapidly, reducing bubble size even more). 

via e-mail

Not entirely. There are many different forms of decompression illness. Some leave few indications of its presence; but some leave significant scarring, particularly in the central nervous system.

Many physicians believe a person should not return to diving if he or she has experienced severe neurological spinal or cerebral decompression illness (Type II) with residual neurological symptoms. One of the reasons for this is the known increased risk of recurrent decompression illness in the area of scarring from the previous sites of the bubbles.

The recommendations for diving after a bout with the bends:

# Type I DCS—If uncomplicated and produced by exceeding dive profiles or ascent rates, a diver may return to diving in four weeks.

# Type I DCS, unexpected—Should return to diving only after ruling out diseases and factors that might increase susceptibility. Change of diving to a more conservative pattern.

# Complicated Type I; neurological and other Type II DCS—Return to diving in a limited manner (no decompression dives, bottom times halved, maximum depth 50 feet and surface intervals of six hours) one month after identifying all causes and undergoing full neuropsychological assessment.

  The sixth Caribbean dive of our week started easily, but when I ran low on air, my fiancée and I
  ascended from 40 feet to our safety stop. Although we ascended slowly, we missed 15 feet. After
  hovering around 10 feet for a minute, we surfaced. The water was choppy, a strong current pulled us
  around, the warm air had cooled and it was raining. We used a towel to keep us somewhat warm on the
  chilly 10-minute boat ride back. After rinsing our gear, we did a brisk walk/jog up 200 steps to our
  hillside bungalow to shower and warm up. My fiancée mentioned that she had cotton mouth and was
  pretty thirsty. Shortly after she got out of the shower her fingers began to ache and were tingly. I ran
  back down to the dive shop and called DAN. They said my fiancée had felt the tingling because she took
  a hot shower when she was cold—more of a circulation issue than DCS. A couple hours later, her hands
  felt fine and there has not been anything wrong since then. Should she get checked out by a dive
  physician anyway?

                                                                     via e-mail

  I don't think so. Coming up cold and tired is typical after a dive. Even though her ascent might have been
  rapid and irregular due to the wave action and surge, increasing the risk of both DCS and pulmonary
  barotrauma (and possible gas embolism), I think DAN made the right call. Both the run up the hill and
  the hot shower can possibly release bubbles in the tissues. However, your fiancée's clinical picture does
  not indicate DCS.

via e-mail

If your husband has a condition called aseptic necrosis of the bone, which causes a collapse of the joint surface and results in joint pain, his diving accident could have caused it, even many years after the injury. This condition is relatively easy to diagnose once X-rays have been taken. When the surface of the joint (generally the shoulders, hips and knees) is affected by the necrosis, physicians usually recommend joint replacement.

  After a Caribbean dive trip, a lump and a bruise appeared on the back of my knee. We made 17 dives in
  a week, including two morning dives on the day before the departure. A lump of one-inch diameter and
  one-half-inch high appeared with sharp pain on the back of my knee when I arrived home. The lump hurt
  when touched, and appeared to be filled with blood (dark blue). The next morning, a bruise appeared
  around the lump; the bruise is now about five inches in diameter. The lump still hurts when I touch it, but
  is no longer blue. I called Divers Alert Network and was advised that I don't have to worry about DCS. I
  wonder if I have gas trapped in the tissue at the back of my knee. What do you think?
 via email, New York, N.Y.

  First, we would agree with DAN that this is not DCS; nor is there the possibility of gas being trapped in the
  tissues behind the knee. There are no air-containing structures in that area, and any nitrogen in the body
  would have dissipated by the time you arrived home.

  The most likely cause of the lump would be the rupture of a small superficial vein in the back of the knee
  caused by pressure from the airplane seat over a prolonged period of time. The small blood clot would
  then slowly spread into the subcutaneous fat, causing the bruise.
  This would have been more likely to occur if you have been taking aspirin or NSAIDS for some arthritic
  complaints.

  I don't think this is a diving-related injury. Your doctor might want to run a few studies on your
  blood-clotting parameters just to be on the safe side.

After two days of diving recently, I developed an irritated throat that progressed to a rather nasty condition—dry and quite sore—for another six days after returning home. Because I am scheduled to take a weeklong live-aboard trip soon, I need some advice on how to prevent dry mouth and throat irritation from repeated diving.

- via email  Allen, Texas

It may be that your problem was a viral pharyngitis or some other infectious condition. It also could have been caused by not swallowing while under water. Saliva can help prevent the dry mouth caused by the dry air in your scuba cylinder. Your saliva glands can be stimulated by using the SeaCure mouthpiece (www.seacure1.com) or placing minty toothpaste on your mouthpiece.

If your dry mouth was caused by dehydration, however, you need to examine your habits before you dive to prevent dehydration on your next dive. The air in your scuba tank is as dry as the Sahara, the moisture having been removed from it in order to protect the inside of your tank and regulator from corrosion. Each incoming breath of dry air picks up moisture from your throat and lungs and carries it out when you exhale, so every breath represents a loss of water.

How much? Not as much as you'd guess from the cotton-mouth feeling that results. On a four-tank day you'll breathe about 260 cubic feet of dry air (assuming 80-cubic-foot tanks—actually 77.4—and a minimum pressure of 500 psi). The maximum amount of water that much air could have contained (at 100 percent humidity, 86F) is about one cup. In fact, you probably lose less. Research reported in the journal Respiration Physiology suggests that most of this water loss occurs in the first 15 minutes when your upper respiratory tract dries out. Regulators that trap moisture in the second stage to moisten incoming air lessen, but probably don't entirely prevent, the drying effect of breathing tank air.
Hydration Hazard: Caffeine

Yes, a cup of coffee is mostly water. But the caffeine is a diuretic, sucking water out of your tissues and sending it to your bladder. As a result, drinking 12 ounces of coffee results in 12, 15, 20 or more ounces of urine and a net loss in your hydration score.

Caffeine is sneaky. It's in more foods and beverages than you might think. Popular soft drinks have a range of caffeine concentrations between 36 and 48 milligrams, with Jolt Cola the chart topper at 72. Coffee has the highest concentration, up to 180 milligrams per five-ounce cup. Tea can have as much as 50 milligrams per cup, and both tea and chocolate are loaded with substances called xanthines, which are also diuretic.

Divers with a severe dry mouth problem may want to consider another equipment solution, the SCUDA (self-contained underwater drinking apparatus) made by SCUDA Marketing. The SCUDA is a wine-skin type device that holds water and allows you to drink through your regulator—squeeze the bag and water squirts into your mouth. The SCUDA doesn't affect the breathing characteristics of a regulator, but because it attaches to the primary hose, it does affect regulator ergonomics. There's also the possibility that you'll gag on water squirted inadvertently or too forcefully into your mouth. The SCUDA is not a great idea for most divers, but those with serious dryness of the mouth may want to try it.

  When diving, I suddenly get the urge to pee, even though I voided only minutes before. Why do I need
  to pee so soon?

                                                                     via e-mail

  This physiological phenomenon is known as immersion diuresis, a fancy term for your body's response to
  feeling under pressure. Blood is shifted to your body's core, and the hypothalamus gland thinks this
  means your total fluid volume is too high and instructs your kidneys to make urine. What can you do to
  avoid immersion diuresis?

       Avoid diuretics like caffeine before you dive.
       Intentionally dehydrating yourself might seem like a good idea, but dehydration increases fatigue
       and predisposes you to decompression sickness.
       Try to stay warm. A side effect of your body's response to cold is the production of urine. Wearing
       a hooded vest under your wetsuit may save you from having to empty your bladder when you least
       want to. On the boat, stay out of the wind, bundle up and wear a hat.
       Be healthy, sober and rested. A variety of over-the-counter and prescription drugs can interfere
       with your body's heat conservation mechanisms, typically by preventing the constriction of blood
       vessels near the skin. Antihistamines are particularly suspect. Alcohol is worse.
       Although adipose tissue insulates well, allowing fat people to tolerate cold water immersion longer
       than lean people, it's better to be physically fit.

Deep Water Blackout

Why Did My Buddy Black Out?
My buddy and I (both very experienced divers) planned a deep canyon dive to 60 meters. At 53 meters, my buddy signaled that he had nitrogen narcosis and was going to ascend. He was ascending very fast, so I stopped him by grabbing his fins. At 30 meters, I grabbed his BC strap and signaled, "Are you OK?" but got no response. He was breathing and had some water in his mask. When we reached 12 meters, he regained consciousness. We continued to the surface, skipping the required safety stop. The dive lasted 12 minutes. We stayed one minute at 53 meters with no deco violation. My dive computer showed that I violated the ascent rate three times. At the surface, my buddy was breathing normally. As soon as we were on the boat I administered oxygen. After the dive ended, he told me that he had felt tingling in his body, that it was very hard to breathe and that he blacked out. What happened? Did I do the right thing?

via e-mail

This is probably "deep water blackout" given a normally functioning regulator. This condition has been described by "Diving Medicine Online" consultant Dr. David Elliott as a combination of low partial pressure of oxygen, high partial pressure of nitrogen and high partial pressure of carbon dioxide. Your buddy's improvement on ascent is revealing. Your quick action probably saved your friend from arterial gas embolism and possible death. I'm delighted to hear that you had oxygen on board, as this was the treatment of choice. Any possible benefit from recompression is a moot point now, of course.

The second stage of his regulator could have malfunctioned and this might have started the whole landslide of hypoxia and hypercarbia and the depth caused the high nitrogen. I have seen one similar case in an experienced diver at 90 feet, which resulted in the rescue and resuscitation from gas embolism due to a "lack of air at depth" and near drowning. His buddy was not as attentive as you, however, and pulmonary barotrauma occurred. He had plenty of air in his tank on surfacing.

  I heard a strange rumor that you should not dive for two weeks after getting a root canal—that on
  ascent, your tooth could explode or pop off. Is this true?

                                                                     via e-mail

  Your concern is not a rumor. If there is any air left in the end of the root canal, this air could implode on
  descent or do just the opposite on ascent. The air is subject to all the forces of Boyle's Law, just as any
  other air-containing structure in the body (sinuses, ears, lungs, intestine).

  If you are about to have a root canal or if you've just had one, follow these recommendations:

       All canals must be filled to the top to avoid accumulation of compressed gases and pain,
       especially on ascent.
       Try to finish the root canal in one visit. Multiple visits require the dentist to place a temporary
       filling over a cotton pellet in your mouth.
       If multiple visits are required, and cotton must be put into the tooth, do not dive. Diving must wait
       until all air spaces or potential air spaces are closed. Diving with an air space can lead to the
       implosion of the tooth.
       Once the root canal is finished, the dentist will fill the space with temporary cement and no air
       spaces. Following a root canal, a cap (crown) is placed on the tooth.
       Wait to dive for a period of two weeks or until there is evidence of complete healing without air
       pockets. 

via e-mail

The only concern about diving with dental implants would be whether you can clamp down on the regulator's mouthpiece without difficulty and without damaging the implants. If the procedure your dentist performed has been successful, and the implants can withstand normal biting pressure, you should be able to dive again. Your dentist can make this determination after he or she has given you the OK to resume normal eating and chewing.

via e-mail

You could try mirror biofeedback. Using a mirror, start with a snorkel, inhale to the count of 4 and exhale to the count of 6 (relax as you exhale). Watch your face relax in the mirror. If you see your face, jaw, eyes, neck and shoulders relax, then you are doing it right. Then try the same exercise with tongue depressors in your mouth. Finally, try it with your reg mouthpiece.

It may be that the mouthpiece of your reg needs to be trimmed. Remove any excess silicone that extends back to your back teeth and trim the excess that hits the roof of your mouth. Another option is to swim laps in the pool with a snorkel until the gag reflex goes away. If you only experience it with a regulator mouthpiece and not with a snorkel (having a virtually identical mouthpiece), it may be that the gagging is anxiety-related, and not anatomical or physiological in nature.

Some dentists sprinkle sugar or salt on the tongue or palate before making dental impressions to inhibit the gag reflex. A topical anesthetic works well—especially Dyclone, which is longer-acting.

Finally, if these suggestions don't work for you, consider getting a full face mask.

  Can Diving Cause Dental Problems?

       I dived for the first time this past winter (seven dives in two-and-a-half days) and since
       then I've needed a lot of dental work done. Do you think there's any connection?

                                                                via e-mail

  Your problem could definitely be related to diving. First, you may have already had dental work that was
  either loose or in need of repair. If there were any air pockets between your fillings and the tooth surface,
  then diving would definitely have caused some changes. The trapped air would change in volume as you
  descended and ascended in the water column, further loosening your repair work.

  Second, you could be using a poorly fitting regulator mouthpiece, causing the repair work to loosen. By
  the same token, you might have clamped your mouthpiece too tightly, causing some tooth damage.

  For more information: www.scuba-doc.com/dentprbs.html.

  Fire Coral Scars

  I came into contact with what I believe was fire coral in the British Virgin Islands about five weeks ago.
  Thinking it wouldn't be much of a problem, I didn't see a doctor until the rash worsened several days
  later, after I returned home. I have been using a prescription cream, Cormax, for four weeks and the
  rash is about 80 percent better. However, the entire area is still visibly darker, almost like a burn scar,
  with a couple bumps. Is there something else I should do? Will this scar completely heal?

                                                                     via e-mail

  Coral scrapes do have a tendency to become both chronically irritated and infected. Occasionally, coral
  scrapes and cuts will have trouble healing and break out in a chronic dermatitis or a weeping wound. This
  is thought to be due to the persistent toxic or allergic effects of the small bits of coral (often microscopic)
  that are embedded in the wound at the time of the injury.

  Initially, wounds should be flushed with large quantities of vinegar or whatever sterile fluid you have
  available. You should get a tetanus shot and treat the wound with a combination of triple
  antibiotic/steroid cream until healing occurs.

  If the wound does not appear to be healing after 24 to 36 hours, check with your doctor to see if you
  need to undergo a procedure called debridement (removal of foreign bodies). Hyperpigmentation (dark
  color changes) is more difficult to manage and requires the assistance of a good dermatologist.

  Cormax is the trade name for clobetasol, a topical steroid cream. It reduces or inhibits the actions of
  chemicals in the body that cause inflammation, redness and swelling. It is used to treat the inflammation
  caused by a number of conditions such as allergic reactions, eczema and psoriasis and would possibly be
  indicated for the coral dermatitis that you seem to have. People have varying reactions to the dermatitis
  and the medication. Most dermatologists are highly trained to manage conditions of this nature and a
  visit to one might be wise in the long run.

  What is seabather's eruption, and when should I worry about it?
  Hamilton, Ontario, Canada

  The skin condition known as seabather's eruption, also called swimmer's itch, appears as a rash of raised
  red bumps, often concentrated on areas of the skin covered by a swimsuit or wetsuit. Symptoms develop
  between two and 24 hours after exposure to the organisms that cause the condition and usually resolve
  within a week. Symptoms can also include nausea, vomiting, diarrhea, headache and muscle spasms.

  Seabather's eruption can be caused by various organisms that produce larvae with nematocysts, including
  jellyfish, corals, sea anemones, hydroids and Portuguese man-o-wars. Outbreaks in the Caribbean and
  southern Florida are believed to be caused by the larval form of the thimble jellyfish.

  Outbreaks of seabather's eruption occur intermittently between March and August in the Caribbean and
  southern Florida, but they appear to peak from early April through early July. There are many days when
  no infestations occur. Beachgoers should listen to local beach reports and read beach messages posted
  daily in affected areas.

  In other tropical waters, seabather's eruption appears to be associated with periodic anemone larvae
  blooms, and can occur throughout the year. See our chart for thumbnail sketches of the animals that
  sting under water, and what to do about the associated injuries. 

Answer: The short answer is—maybe.

Until the middle of the 1990s, the official medical advice was that diving with diabetes was too risky. Thanks to research by Steve Prosterman of the University of the Virgin Islands, the Undersea and Hyperbaric Medical Society, the Divers Alert Network (DAN) and the British Sub-Aqua Club (BSAC), we've learned a lot in the last few years, and today, it's a case-by-case decision based on how well the diabetic controls his condition.

If you're a diabetic who dives or wants to dive, the first step is to consult your personal physician to learn as much about controlling your condition as possible.

Question: How can diabetes affect a diver?

Answer: Diabetics can be at risk from the effects of both the condition and the methods of controlling it.

    * The possibility of seizures and loss of consciousness from hypoglycemia has been the big obstacle to certifying diabetics.
    * Insulin reactions and the resulting rapid onset of low blood sugar levels can impair judgment.
* Diabetics not in control of their condition excrete excess sugar in urine, a process that leads to dehydration and puts the diver at greater risk of DCS.

Question: So who can and can't dive?

Answer: Any diabetic who can't recognize hypoglycemia (low blood sugar), hyperglycemia (high blood sugar), or who is diagnosed with ketoacidosis (acidic condition from breakdown of ketones) or organ disease (kidneys, eyes, heart) must be disqualified. Sorry, the risks are still too great.

The good news: Diabetics who practice excellent self-management, understand the relationship between exercise and diabetes, and are disciplined enough to follow these guidelines are qualified for conservative sport diving without problem.

The Guidelines
Before Diving

    * Wear a medical ID stating that you are diabetic and also a diver.
    * Hydration is doubly important to the diabetic diver to prevent decompression illness.
    * Maintain good physical condition and good diving skills.
    * Don't dive if you: Can't recognize when you are having a reaction, don't completely understand your condition or if you have any concurrent illness.
    * Tell the divemaster. He or she must be aware that you're a diabetic and should also be informed of your intended profile.
    * Tell your buddy. The diabetic diver's buddy should be familiar with the diabetic, aware of potential problems and properly trained in responding to them.
* Monitor and stabilize blood glucose. Blood glucose should be monitored before every dive and stabilized at 150 to 180 mg/dl prior to the dive. Steve Prosterman, dive supervisor at the University of the Virgin Islands, recommends a minimum of three blood glucose measurements within one hour prior to diving (e.g., 1 hour, 30 minutes, and five to 10 minutes prior).

"The important thing is to find the direction of the blood glucose. Under no circumstances should a dive be performed if the blood glucose is dropping," Prosterman says. "If it's going down, take carbos to stabilize it. Usually it can be corrected after the second test."

If blood glucose levels are rising, aim for a minimum reading of 120 to 130mg/dl before diving.

* Pack a dive kit. This must include: two separate packs of oral glucose paste or tablets in waterproof containers; an emergency intra-muscular injection of glucagon to rapidly raise dangerously low blood sugar levels (make sure someone in your dive party is capable of administering the injection); and a glucose-measuring kit with instructions.

During the Dive

    * Always carry oral glucose under water. A glucose gel in a plastic container, like InstaGlucose, is recommended. Both the diver and his non-diabetic buddy should carry two tubes each.
    * Communicate with your buddy. The diabetic diver and buddy should have hand signals and an abort plan well established in the event of a reaction under water. Prosterman recommends an "L" sign for low blood sugar. When the sign is given, both divers surface and inflate their BCs. The diabetic immediately ingests carbos before the buddy team returns to the boat or shore.
* Limit your depth to 80 to 90 feet. This will help you avoid nitrogen narcosis, which may be confused with—or mask—an insulin reaction. Under no circumstances should diabetics engage in decompression diving, which limits the diver's ability to surface promptly in case of low blood sugar.

After the Dive

    * Check your glucose level. Correct as necessary. By tracking the drop in blood sugar after dives, diabetics can learn to better control their condition.
* Report any adverse symptoms. Symptoms of low blood sugar can mask decompression illness (DCI) and vice versa. Unless there is a reason to suspect DCI, Prosterman recommends treating for low blood sugar first, which will resolve in 10 to 15 minutes. If symptoms do not resolve with glucose, treat the case as a dive accident by administering 100 percent oxygen and calling for medical help.

Answer: Absolutely.

For years, diabetic divers have hidden their conditions in order to participate. As the dive community begins to recognize the new rules for diabetes, the safest—and most responsible—course of action is full disclosure. It's important that your buddy and divemaster be fully aware of potential reactions and how to respond to them.

What is Diabetes?
Diabetes mellitus, also called "the sugar disease," occurs when the pancreas can't produce enough of the hormone insulin to convert glucose from food into energy. It affects five to seven percent of the population.

There are two main types of diabetes. Type I, also called insulin dependent diabetes, normally affects children or adolescents.

Type II, also called non-insulin dependent diabetes or adult-onset diabetes, accounts for 90 percent of cases and usually occurs in overweight adults.

Treatments for diabetes include daily insulin injections to lower high blood sugar levels, oral medications, regulating the diet, exercise and constant blood glucose monitoring.

Are there diving programs for Diabetics?

There's no better role model for diabetic divers than Stephen Prosterman, diving supervisor at the University of the Virgin Islands. Diagnosed at the age of nine, Prosterman never let his condition get in the way of an active lifestyle. And when he moved to the islands more than 20 years ago, that lifestyle soon included diving.

His love for the sport led him to create the first protocol for responsible diving with diabetes, and this work spurred much of today's ongoing research. It also led to Camp DAVI, an annual summer program for diabetics 17 and older that uses diving and other adventure sports to teach campers how to tightly manage their condition. The program, overseen by Dr. Doren Frederickson of the Kansas University School of Medicine, also advances research into diving with diabetes.

For more information on Camp DAVI, call (340) 693-1399, e-mail Steve Prosterman at sproste@usvi.edu or visit the web site at www.diabetesnet.com/visle.html.

Warning Signs of Diabetes?
Adult-onset diabetes usually occurs in overweight middle-aged people. Sound like anyone you know? See your doctor immediately if any of the following symptoms apply to you:

    * Any family history of diabetes.
    * Frequent urination.
    * Unexplained weight loss.
    * Ravenous appetite.
    * Constant thirst.
    * Constant sleepiness.
    * Blurred vision.
    * Sticky urine.
    * Shakiness after a high-carbohydrate meal.
    * Easy fatigue and nausea.
* A tendency to get fungal and bacterial infections.

According to the National Diabetes Information Clearinghouse, 798,000 new cases of diabetes are discovered each year. Unfortunately, an estimated 5.4 million people remain undiagnosed and are at risk for the long-term damage that can result—including heart disease, stroke, high blood pressure, blindness, kidney disease and nervous system damage.

    * Go to the "Fitness to Dive" section of "Diving Medicine Online" at www.scuba-doc.com and look up the condition, illness or disease for which the medication is being given and find whether there are any prohibitions against diving with that condition or while taking that medication.
    * Determine whether the drug alters consciousness or causes alteration in decision-making ability.
    * Consider complex relationships between drugs, the individual, other medications, diet and the conditions for which the drugs are taken.
* Consult a physician who is trained in dive medicine. 

via scubadiving.com
message board

Benadryl is an over-the-counter medication that causes some side effects in some people. The fact that it causes drowsiness in some people does not indicate that it would necessarily be dangerous to all divers. Diving per se is not known to increase its effect. It is doubtful that the FDA would turn it loose if there was major danger. After all, there are a lot more drivers than divers.

Every drug or medication has some side effects on some people. One should not dive after taking this or any drug until their response to the drug has been determined.

However, since the mild depressant effects of antihistamines are additive to those of other drugs affecting the central nervous system, patients should be cautioned against drinking alcoholic beverages or taking hypnotics, sedatives, psychotherapeutic agents or other drugs with central nervous system depressant effects during antihistamine therapy.

Diphenhydramine should be used with caution in patients with a history of bronchial asthma, increased intraocular pressure, hyperthyroidism, cardiovascular disease or hypertension, all of which are clear hazards to divers if uncontrolled. Other listed adverse effects of Benadryl include: drowsiness, dizziness, dryness of mouth, nausea and nervousness. Other infrequently reported effects are vertigo, palpitation, blurring of vision, headache, restlessness, insomnia and thickening of bronchial secretions. Allergic reactions, diarrhea, vomiting and excitation may also occur.

ENT Problems

Trouble Clearing
This summer I made two quarry dives to 50 feet. On the second dive, I had trouble clearing my right ear. I went up and tried again, but still no luck. On the third attempt, I felt it clear--well, sort of. Instead of the usual pop, I heard a series of squeaks from my right ear. Could it have been caused by my mask and hood covering the area? I always take Sudafed an hour prior to diving as a doctor recommended many years ago after a sinus problem. On the way home, I had mild discomfort in that ear. That night I took two aspirin, and I was fine the next day. Do you think I damaged my eustachian tubes? Do they heal? Should I see a doctor?

- via email, New York, N.Y.

It is possible that you have some type of blockage of your nasal lining near the opening of your eustachian tubes, possibly polyps, bony growths, nasal septal deviation or allergic rhinitis. If it comes and goes, the most likely cause would be that the mucosa is swelling at various intervals, possibly as the result of allergy, irritations from fumes or from congestion from any of a thousand other sources. This may have caused some middle ear barotrauma, with swelling and serum accumulation in your middle ear.

If a good ear, nose and throat exam fails to expose any pathology in the back of your nose, then you might need to check into your diving technique. Descending feet-first on the anchor line or a down line can help you rise slowly just a foot or two to take the pressure off and help you clear easily.

Try a Different Clearing Technique

You might also want to try using a different technique for clearing your ears. The Valsalva maneuver--pinching your nostrils and blowing through your nose--is the most commonly used technique, but might not be the best one for you. One problem with the Valsalva maneuver is that it doesn't activate muscles that open the eustachian tubes, so it may not work if the tubes are already locked by a pressure differential (see illustrations). It's also easy to blow hard enough to damage something. Instead of using the Valsalva next time, try one of these:

    * The Toynbee Maneuver. With your nostrils pinched or blocked against your mask skirt, swallow. Swallowing pulls open your eustachian tubes while the movement of your tongue, with your nose closed, compresses air against them.
    * The Lowry Technique. A combination of Valsalva and Toynbee: While closing your nostrils, blow and swallow at the same time.
    * The Edmonds Technique. While tensing the soft palate (the soft tissue at the back of the roof of your mouth) and throat muscles and pushing the jaw forward and down, do a Valsalva maneuver.
    * The Frenzel Maneuver. Close your nostrils, and close the back of your throat as if straining to lift a weight. Then make the sound of the letter "K." This forces the back of your tongue upward, compressing air against the openings of your eustachian tubes.
    * Voluntary Tubal Opening. Tense the muscles of the soft palate and the throat while pushing your jaw forward and down as if starting to yawn. These muscles pull the eustachian tubes open. This requires a lot of practice, but some divers can learn to control those muscles and hold their tubes open for continuous equalization.

Try Medications

In addition, you can use medications that help reduce the swelling around the opening to the eustachian tubes. Most people use and get good results from oral Sudafed tablets. Afrin nasal spray, for a day or two only, also is helpful, but can cause troublesome rebound congestion. Taking oral Sudafed throughout a dive trip would not be harmful, nor would it cause rebound congestion. The newer antihistamines (Allegra, Claritin and Zyrtec) might be helpful, taken on the advice of your physician. Flonase is also helpful for some people.

For more information on dealing with ear troubles, go to: www.scubadiving.com/training/medicine/earproblems.shtml or www.scuba-doc.com/entprobs.html.

via e-mail

Unequal clearing usually indicates one of two things: poor technique or some abnormality in the back of the nose causing blockage of the opening to the eustachian tube.

Though you've tried various methods to help clear your ears, read "Pain-Free Equalizing," in case there is a method you haven't tried.

If it's an abnormality that's preventing you from equalizing, there is good news. Lots of these can be corrected easily, including polyps, allergic rhinitis and bony growths around the opening to the eustachian tube. A visit to an ear, nose and throat specialist can determine if you have one of these conditions.

via email
Greenville, S.C.

There are no scuba apparatuses or equipment that will perform the function that you wish. There probably are people who are born with congenitally small or narrow Eustachian tubes, but this would definitely be the minority. Most people have a correctable cause for their inability to equalize when diving. You are strongly advised to see a good ear, nose and throat specialist who is diving oriented and find out if you have some problem that can be altered surgically.

Blood in My Mask
I usually have some blood in my mask (it all comes from my nose) after diving. Blowing my nose usually reveals some orange stuff that doesn't seem to help me attract much positive attention from the ladies. I tend to equalize pretty slowly, but the presence of the orange stuff doesn't seem to be dependent on difficulty in descending.

I'm assuming it's a mixture of blood and mucus. Am I going to live? Will I ever play the piano again?

by email

The old "blood in the mask" gambit is guaranteed to scare the diver, get attention from his buddy, attract sharks and other top-of-the-food-chain animals, and turn off the ladies (and anyone else who doesn't like orangish-pink snot). You'll survive, though I don't know if you'll ever play the piano again.

All kidding aside, yours is a frequently asked question (because it happens frequently) and the simple answer is that it is harmless, usually caused by mask squeeze, sinus barotrauma or excessive nose-squeezing with clearing attempts. If you are concerned, it might be wise to go to an ear, nose and throat doctor and be certain that you don't have something that can be corrected—such as septal deviation, chronic rhinitis, polyps or tumors.

For more information, go to:
www.scuba-doc.com/otherent.htm
www.scubadiving.com/training/medicine/sickdive.shtml

       I apparently have an ongoing sinus infection that is only evident when I dive. I take the
       prescription drug Augmentin with me now when I go on vacation because without it I
       sometimes get pressure in my sinuses when I descend. Both my regular doctor and a
       specialist say that the infection is something that is most likely ongoing and will never be
       completely eradicated, only diminished with antibiotics. It causes me absolutely no
       problems topside. No allergies, no itchy, watery eyes, nothing. It only shows up when I
       dive. What is going on?

                                                                via e-mail

  You probably have something obstructing the outlet of the affected sinus—such as a deviated septum,
  polyp, scarring or other growth.

  This is apparently not a problem when you're not diving, but causes blockage due to pressure changes on
  descent and ascent. The lining of the blocked sinus is damaged by the pressure changes, resulting in
  swelling and hemorrhage and allowing a flare-up of any bacteria that might be lurking around in the
  sinus.

  The appropriate antibiotic depends entirely upon the type and kind of bacteria present—as determined by
  nasal cultures and sensitivities. Augmentin is a broad-spectrum antibiotic and should handle most
  bacteria of the kind living in the nasal cavity. However, some germs are resistant and this might cause
  your doctor to change to a more specific drug.

  This problem will continue until you find the cause and get it managed properly, possibly surgically.

       Q: I have been certified for one year and have completed approximately 30 dives. I was recently diving and sometime
       in the middle of the week had a strange experience. I started my descent and at about 15 feet started to feel an intense pain across my forehead, around the top of my mask. I thought perhaps my head was sore from wearing my mask on consecutive days. I continued my descent, equalizing as I went, hoping it would stop and wondering if I should abort the dive. I do not recall having ear pain. By the time I got to 60 feet, the pain was gone.

       I followed my group for the drift dive and sometime later realized there was warmth around my nose and figured I
       had a nosebleed. Since it was not bothering me, I continued the dive. When we surfaced, my husband/buddy was
       shocked to see blood in my mask. He didn't want me to dive again that day, but I cleaned up on the boat, stopped the nosebleed and did the second dive with no problems.

       Do you have any idea what caused the pain? Should I have aborted the dive? Should I have done the second dive?

                                                                      via e-mail

       A: Severe headache and nosebleeds associated with diving are almost always due to sinus
       barotrauma. Bleeding can also be caused by trauma from squeezing the nose too tightly during
       attempts to clear the Eustachian tubes. The sinuses are air-filled and are subject to the same
       pressure changes of descent and ascent as the ears. If the sinus cannot equalize due to blockage
       of the ostium (opening into the back of the nose), there will be damage done to the vascular
       mucous lining of the sinus. For more on headaches while diving, go to
       www.scuba-doc.com/headache.html.

       You should have aborted the dive if you bled enough to be unable to see through your mask.
       Rarely do nosebleeds cause enough bleeding to become dangerous to a diver, and then only if
       associated with severe hypertension or blood vessel tumor. The decision to make the second dive
       is debatable in light of the volume of blood and the history of the first dive.

       If bleeding is persistent and heavy, then you should seek medical consultation from a
       diving-oriented ear, nose and throat doctor to check for other problems, such as septal deviation,
       polyps, hemangiomas or tumors. The hard part might be in finding a doctor who knows something
       about diving medicine. You can call DAN and request a referral (919-684-8111). 

via email
Miami, Fla.

You'll want to refer to "The Diver's Complete Guide to the Ear" in which we describe all the methods for equalizing your ears. The Frenzel maneuver described by DAN is: "Adding air to the middle ear by closing the nose, mouth and glottis voluntarily, then driving the tongue backward, which acts as a piston to compress air into the nasal cavities and through the eustachian tubes." In other words: Close your nostrils and the back of your throat, and thrust your tongue against the soft palate. This gently forces air through the eustachian tubes.

via e-mail

You probably did the right thing. Nasal congestion and blockage can lead to sinus and middle ear barotrauma. And the resulting sinus infections and middle ear damage and infections can cause hearing loss and balance problems. 

What Is the Treatment for Middle Ear Barotrauma?

Is there a specific treatment for middle ear barotrauma to help eliminate the pressure and fluid in the ear? How long does this generally last?

via e-mail

Barotrauma of the middle ear occurs from swelling and bleeding after the ear is damaged from a diver's inability to equalize pressures on descent or ascent. Treatment involves reducing the swelling, draining the serum and blood through the eustachian tubes, and treating any infection that occurs when the eustachian tubes are blocked.

This treatment generally consists of oral decongestants and antibiotics. Antibiotics are used only when there is fluid in the middle ear and there is the possibility of infection. If perforation is present, oral antibiotics should be used. Ear drops are not advised if there is perforation of the eardrum.

Middle ear barotrauma usually clears up anywhere from several days to six weeks, depending upon the degree of damage done and whether or not there is a perforation of the eardrum.

Divers with middle ear barotrauma should not dive until all symptoms have cleared. If there has been perforation, do not dive for at least six weeks after the perforation has healed. No ear drops should be used in the event of rupture, as damage can be done to the middle ear.

Diving and Tinnitus (Ear Ringing)
I have heard that ear ringing after a dive may be a sign of something. What?

via e-mail

Ringing in the ears or "tinnitus" is one of the most prevalent and bothersome of symptoms related to diving. Tinnitus may be caused by damage or disease anywhere along the path of the auditory system. In divers, it can be related to TM joint pressure from clamping down on the mouthpiece, wax buildup in the ear canal with tympanic membrane irritation, barotrauma to the middle and inner ear, decompression illness involving the inner ear or rupture of the round window with perilymph fistula. It is most often found in association with vertigo (dizziness) and there is usually some deafness.

During the last two decades, hyperbaric oxygenation therapy (HBO) has been used in the treatment of sudden deafness and chronic distressing tinnitus, with mixed results. It should be emphasized that this and other newer methods of treatment are still under evaluation. At this time there is no universal, symptomatic or specific treatment for tinnitus.

What divers can do:

    * Get a good examination by a diving-oriented ear, nose and throat doctor. The tinnitus may not be from diving at all. If it is related to diving, early treatment may be helpful.
    * Check out your regulator mouthpiece for fit. Consciously avoid clamping down on the mouthpiece. It may be that your dentist can help. Try this yourself—clamp down on your teeth and hear the high-pitched whine.
    * The use of nerve stimulants is to be avoided. Therefore, excessive amounts of coffee (caffeine) and smoking (nicotine) should be avoided. Aspirin is a common offender.
    * Learn as quickly as possible to accept the existence of the head noise as an annoying reality and then promptly and completely ignore it as much as possible.
* Tinnitus is usually more marked at bedtime, when one's surroundings become quiet. Use any kind of masking noise-maker that won't keep you awake.

Additional information can be obtained from the American Tinnitus Association (P.O. Box 5, Portland, OR 97207-0005).

On the web, go to:
www.scuba-doc.com/inearprobs.htm

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.

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.

via email
Norfolk, Va.

Not all ear infections are the same, nor is all water that you dive in the same. I assume that your query concerns otitis externa, or infection of the ear canal. It may be that you haven't gotten rid of the first infection before you dived again. Sometimes these infections require a full 10 days of treatment with ear drops containing an antibiotic.

Ear canal infections can be easily prevented by the judicious use of ear drops after each dive. These drops are for changing the acidity and moisture of the ear canal so that organisms cannot survive. Cleanse external canals of occluding wax and avoid trauma from Q-tips, bobby pins, etc. Use a good ear solution to maintain a slightly acidic environment. SwimEar or Star Otic.

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.

Exercise and Diving

How Will Exercise Affect My Diving Experience?

I am an extremely fit 62-year-old who regularly works out at my local gym. I am planning a trip to Grand Bahama Island and would like to continue my regular gym routines coupled with extensive scuba and skin diving. How much is too much? I have 40 years of diving experience, but this is the first time I will have the chance to experience virtually unlimited diving in warm water. What would you suggest?

via e-mail

First, congratulations on keeping yourself fit. This is something that you can continue to do on your dive trips, with certain precautions. The results of some studies suggest that the risk of neurologic decompression illness is reduced by physical conditioning, and the effect is independent of differences in age and weight.

You definitely should not exercise in the time period immediately after a dive while off-gassing or within several hours after a series of dives. Also, scotch any plan for mountain climbing immediately after diving.

If you exercise and plan to dive following the exercise, it would be wise to allow for a cool-down and rehydration period.

via e-mail

Even if the race includes ascending to significant altitude, as might be the case on Maui, you can dive. Make sure you're completely rehydrated from your race, as dehydration is a real risk for decompression accidents. It is also recommended that you have a cool-down period of several hours between your dives and any strenuous activity.

You should not, however, run or hike to altitude soon after diving. Stay at sea level at least 12 hours after a single dive or 24 hours after multiday, repetitive diving.

via e-mail

We get asked this question a lot, especially from dedicated runners, swimmers, hikers and gym rats. It takes about 24 hours to eliminate residual nitrogen from your body. There is some debate about whether exercise, especially strenuous activities such as running or mountain climbing, is risky during that period of time. Those who advise divers not to exercise immediately after diving say that it might increase the chances of bubble formation from residual nitrogen levels.

The research on exercise after diving can be contradictory. There are some inconclusive reports that point to physical stress as the cause of DCS in some divers who exercise after diving. But there is also evidence that exercising while decompressing is helpful in reducing decompression accidents.