Intern@tion@l Dre@m.net

By Sam Shelanski, M.D.

Don't Panic! | Be Intelligent | Overconfidence Kills | Avoid Heartbreak | The Bottom Line

Alphabet Soup | U.S. Fatalities By Year

How safe is scuba diving? This is a question that I am often asked by non-divers. The answer is complex because nobody--no matter what they claim--knows how many people are really diving each year, making it hard to compare accident rates to other sports. But it is clear that we can learn much from the trends in diving accidents found in the annual "Report on Decompression Illness and Diving Fatalities" from the Divers Alert Network (DAN).

First, the numbers. In all, DAN collected data on 483 diving accidents and 85 diving-related deaths in 1996, the latest full year of data. The 85 deaths represent a significant drop from the previous year when there were 104 scuba-related fatalities. In fact, 1996 saw the fewest deaths since 1988, when there were 66. Since we don't know how many people were diving in each of these years, it's hard to say whether this decrease in fatalities means safety is improving--or if it simply means fewer people are diving.

Of the accidents treated in 1996, there were 122 cases of Type I decompression sickness (DCS); 303 cases of the more serious Type II DCS; and 58 cases of arterial gas embolism (AGE) (see: "Alphabet Soup").

More important than the raw numbers are the lessons all divers can learn from these accidents. The latest DAN report shows four preventable factors related to the majority of mishaps.

(Top)

Don't Panic!

As is true every year, a significant number of the injuries and deaths are attributable to divers panicking under water. While exact statistics are not available, panic is accepted as the main reason why divers make uncontrolled rapid ascents. Rapid ascents in turn were admitted to by almost 60 percent of the divers who suffered arterial gas embolisms in 1996. In addition, panic was listed as a contributing factor in over 20 percent of the dive fatalities upon which DAN had data for 1996.

So how do you beat panic? By being physically and mentally prepared for the dive. Physical preparation involves having the proper equipment and making sure it functions correctly before the dive. While this may sound all too obvious, fatalities cited in the DAN study included a diver who entered the water with only 1,000 psi in his tank; two cases of divers who entered caves without a means to locate the exit; and a diver who tried to retrieve a fishing net but became entangled and drowned when he could not cut himself free.

Mental preparation is also important. If you do not feel comfortable diving in a certain situation, don't. If you do not have the training to dive under certain conditions, don't. In 1996, 10 scuba deaths involved certified divers who were performing dives they weren't qualified to do. This included cave, wreck and deep dives. Each year, five to 15 divers die trying to dive beyond their limits. If your buddy is a certified cave diver, wreck diver, or cold-water diver, and you want to join him, get the necessary training first.

(Top)

Be Intelligent

I realize that most of us dive a few times a year while on vacation, and that huge amounts of time, effort and money are expended on these trips. Unfortunately, we sometimes let these factors cloud our judgment and put the dive ahead of our safety.

The DAN report describes 17 divers who had severe neurological problems from DCI, but continued to dive. They include two divers who had numbness in their legs and difficulty walking, a diver with difficulty speaking and facial tingling, and another who was light-headed and coughing up blood. Despite these not-so-subtle hints, they continued to dive without seeking medical attention.

If there is something obviously wrong--whether or not you think it's diving-related--don't dive until you've seen a doctor. I don't care how much time and money you spent to get to the fabled reefs of Outer Brou-Haha, there is no dive worth your life or your health.

(Top)

Overconfidence Kills

You're no newbie. You've seen it all, done it all--twice. And while some 30 percent of injuries and 40 percent of deaths happen to divers with fewer than 20 dives, the fact remains that about 46 percent of the injuries and 33 percent of deaths occur in experienced divers--defined as having 61 or more lifetime dives. It's unclear whether this is due to overconfidence or a statistical blip (maybe these divers perform most of the dives?), but it is clear that dive injuries and fatalities should not be written off as something that happen only to beginners.

One chilling statistic that does involve beginners: divers under an instructor's supervision accounted for nine percent of reported diving injuries and a staggering 15 percent of deaths.

(Top)

Avoid Heartbreak

Cardiovascular disease, or heart problems, continue to be one of the most common contributors to diving fatalities. From 1990 to 1995, fully 26 percent of the fatalities involving divers over the age of 35 listed cardiovascular disease as the leading, or a significant contributing, cause of death. The percentage didn't change in 1996: 16 of the 60 dive deaths for which there is autopsy data listed heart problems as causing the diver's death or contributing to it.

Diving is perceived as a sport that places little strain on its participants. Unfortunately, some divers are ill-prepared to face the unexpected current, long surface swim or other situation that may require significant physical exertion. Divers who aren't used to daily physical activity may have no clue as to their limitations, and under water is no place to suddenly become aware of your heart disease.

The risk factors for heart disease are well-known. They include:

·        Age--if you are a male over the age of 45 or a post-menopausal female

·        Smoking

·        High blood pressure

·        Diabetes

·        Family members with heart disease

·        High cholesterol

I suggest that any diver over the age of 40, or with two or more of the listed risk factors, be evaluated by a physician prior to starting diving, and every three to five years thereafter. Ideally, divers should have an exercise stress test to look for any evidence of heart disease during exercise. Diving should be considered a potentially strenuous sport, and people who wish to participate should be screened accordingly. If your physician doesn't understand the specific risks associated with diving, then contact DAN's medical department at (800) 446-2671 for a list of doctors in your area who may be able to help.

(Top)

The Bottom Line

Overall, the numbers are encouraging. As divers we speak of dozens of deaths, and hundreds of injuries as opposed to the thousands of deaths and hundreds of thousands of injuries attributed to sports like skiing, roller-blading and bicycling. But whether this means that diving is safer than these sports, or that there are simply fewer participants, really doesn't matter. What is important is that through proper training and awareness of risk factors, divers can avoid injuries and continue to make the sport safer.

(Top)

Alphabet Soup

Alright, I give up! What do all of those letters and acronyms stand for?

DCI: Decompression Illness. This is a catchall term to describe all the injuries caused by ascending from a high-pressure environment to a low-pressure environment. It includes DCS and AGE.

AGE: Arterial Gas Embolism. This term refers to small air bubbles in the bloodstream. This is almost always the result of a rapid ascent, with or without breath-holding, which causes the lung tissue to tear and allows air into the blood vessels.

DCS: Decompression Sickness. This is what has classically been referred to as "the bends." This is broken down into two types:

Type I DCS: This is DCS that results in joint or muscle pain, extreme fatigue or skin manifestations.

Type II DCS: Includes any DCS hit that has neurological or cardio-respiratory symptoms.

(Top)