The Diving Medical

By Dr. Sawatzky

The purpose of a diving medical is quite simple. It is to determine if it is safe for a specific individual to dive. The details of how you actually do this are much more complex! For example, when I perform a diving medical, I am actually NOT trying to determine if it is SAFE for the person to dive, I am trying to determine if there are any reasons it would be UNSAFE for the person to dive. There have been several books written about how to conduct a diving medical and they still leave many questions unanswered. Therefore, I am going to give you a philosophical approach to the diving medical, hopefully the same approach your physician will take.

There are some medical problems that are incompatible with diving. The physician can and should declare these people unfit to dive, no discussion. For example, a person has a spontaneous pneumothorax (collapsed lung) while walking down the street. He (usually tall males) is taken to the hospital, treated, and makes a full recovery. Two years later he turns up in my office for a diving medical. These individuals are born with weak areas near the tops of their lungs and often suffer repeat collapsing of their lungs. If this happens while they are diving, they have a high probability of dying. Therefore, I will make him unfit for diving, for life (unless he has some forms of treatment that are beyond the scope of this discussion).

However, many problems are not so black and white. In some cases, the individual has only a slightly increased risk of experiencing difficulties while diving. The physician should identify the potential problems and fully explain them to the diver. It is then up to the individual to decide if they are willing to take up or continue diving, given the increased risk. For example, a 25 year old woman comes to see me for her diving medical. While taking the history, I learn that she had some problems with asthma as a child. However, since age twelve, she has only had to use an inhaler a couple of times (when she had bad bronchitis), the last episode being two years ago. She also wheezes when she's around cats. This lady has no exercise limitations, does not wheeze when she runs in the cold and I hear no wheezing when I listen to her lungs. This is a much more difficult case to determine whether it is safe for her to dive. I would want full pulmonary function tests and if they were essentially normal (I would expect mild small airway dysfunction), I would strongly counsel her that she should not dive when she is sick or when she is wheezing. I would also emphasize that even when she is not sick or wheezing, she has an increased risk of pulmonary barotrauma. This risk can be reduced but not eliminated if she always ascends slowly, especially the last 20 feet to the surface. In this case, it is up to the individual to decide if they are willing to accept the increased risk of diving with their medical problem.

In other cases, the individual has a medical problem that might prevent them from attaining the required knowledge or performing the required skills to dive safely. For example, a 45 year old man comes in for his diving medical. He had a lot of trouble with school and only finished grade nine. As I am talking to him, it becomes quite clear that he is going to have significant difficulty with the academic portion of dive training. In this case, it is up to the instructor to determine if the person can learn what he needs to know to dive safely and the only way to do that is to let him try the course. The doctor should explain the potential problems to the student (and alert the instructor) and the instructor should explain to the student the first night that he might not pass the course.

Let's look at a second example. The doctor sees a diving candidate who broke both arms as a child and who now has moderately severe limitations on their range of motion and some weakness of the arms. Diving is not going to make this person worse and therefore, the doctor should declare the person fit to dive (depending on the injury, there might be a slightly increased risk of DCS). However, there is some question as to whether this person will be able to perform all the skills required to dive safely and to help their partner in an emergency. The instructor must make this determination during the course. The instructor and the physician should be working together on these difficult cases (I am also an active scuba instructor and therefore know both sides of this situation).

To clarify this even further, the diving medical should determine if the person has a medical problem that will be made worse by diving, or if the person has a medical problem that increases their risk of dying while diving. The diving instructor should determine if the person has acquired the required skills and knowledge to dive safely. Doctors declare people "medically" unfit to dive, instructors must declare people "practically" unfit to dive. Some students should and must fail diving courses.

During the diving medical, we are trying to identify problems that would make it unsafe for the person to dive. Most references go through the systems and attempt to list and discuss all the medical conditions that might be problematic with diving. This is impossible in a few hundred words. Therefore, in this discussion, I will work backwards, from the skills and abilities required to dive safely, to the medical problems.

First, to avoid barotrauma, you must be able to clear all of the gas spaces in the body. Therefore, on the diving medical we need to search for any history of problems in these areas. Is there anything to suggest problems clearing the ears and sinuses? Any history of stomach or lung problems (including smoking)?

A diver also needs to remain conscious and alert. Therefore, we look for any loss of consciousness or any disease that might result in loss of consciousness (epilepsy, seizures, trauma, diabetes, hypoglycemia, etc.). We also need to look for any indica tions of panic, phobias, drug abuse (including alcohol), psychotic problems, and we need to examine the person's motivation to dive.

A diver needs to be able to move their gear, get in and out of the water, help their buddy or anyone else having difficulty. Therefore, we need to check for any musculoskeletal problems, although it will usually be the instructor who needs to determine if the person is capable of diving safely. A diver needs to be able to hold a regulator in their mouth (check teeth, etc.) and of course should NOT dive while pregnant.

As should now be obvious, a diving medical is primarily a hunt for any medical problems. These problems then need to be evaluated to determine if they are compatible with the form of diving the person is planning. Depending upon the problems identified, consultation with a more experienced diving medical physician may be required. The bottom line is that no matter how "good" the doctor is, the decision as to whether a person is fit to dive or not is based primarily on the history given to the doctor by the patient. Of course you can "forget" to mention your asthma or "forget" to mention all of the drugs you are taking and the doctor will most likely sign you off as being fit to dive. However, you are the one who will die if you are truly not fit to dive, not the doctor.

The last point I need to make about the diving medical is that the "standards" depend entirely upon the type of diving the person plans to conduct. For example, the recreational diver can usually choose the time, place and water conditions of the dive. They are not usually required to work hard during the dive and they usually dive to relatively shallow depths. In addition, there is usually minimal financial or peer pressure forcing the person to dive. Therefore, the recreational diver can easily decide to cancel or abort a dive. The commercial diver does not usually have these options and therefore the medical standards are much higher for a commercial diver.

When I perform a recreational diving medical, I am "working" for the diver, trying to determine if it is safe for them to dive. When I perform a commercial diving medical, I am "working" for the company, trying to determine how often the diver is going to be unable to dive (costing the company money) and how likely it is that the diver is going to suffer a problem while diving (and sue the company). In commercial diving, there is also a "supply and demand" factor. If there are lots of divers and only a few jobs, only the medically "perfect" divers will get work. Technical diving falls between recreational and commercial diving. The diver is essentially doing "commercial" types of diving and therefore requires a higher level of medical fitness. However, they are not usually getting paid and therefore they can decide not to dive on a particular day more easily than a commercial diver.

In conclusion, the purpose of the diving medical is to determine if it is safe for a person to dive. The fitness of the person depends upon the medical problems identified and the type of diving the person is planning. Remember, the doctor determines if it is SAFE for the person to dive, (is the act of diving likely to harm the person) while the instructor must determine if the person is CAPABLE of diving safely.