Page 46 - AlertDiver_Summer2011_web

Q:

I recently had a concussion. Is it safe to dive? A:

The risks associated with diving after a head injury are directly related to the severity of the injury and the time elapsed since it occurred. The primary concerns for dive fitness are diminished cognitive ability and post-traumatic convulsions.

Even minor head trauma can cause brain injuries that may lead to unconsciousness or amnesia. In addition to diminished cognition, a post-concussive syndrome may manifest as recurring headaches, dizziness, poor concentration and memory, unsteadiness and irritability. Anxiety, depression and personality changes can also occur. Any of these symptoms have the potential to severely distract a diver and might cause diagnostic confusion with decompression sickness (DCS) if they were to occur after diving.

The likelihood of post-traumatic convulsions diminishes over time, so divers should delay diving for at least three years following a severe head injury, one year following a moderate head injury and one month after a mild, uncomplicated head injury. The severity of a head injury is determined by a physician and is based on the length of post-traumatic amnesia — the time from the injury until the beginning of uninterrupted memory. It is likely all symptoms will have resolved by the time these delays have been met, but if any symptoms persist, a doctor with specialized training in dive medicine should approve of diving before you return to the water. Deficits in memory, understanding and concentration are obvious risks

in diving. The extent to which such symptoms might impact medical fitness for diving can be estimated by social, school or job performance. If these skills are intact, it is unlikely your physician would restrict diving. Motor skills must be normal,

and you should not have any diminished ability to handle stress, prioritize or remain focused. Diving does not worsen the symptoms of head injuries. Q:

I am signed up for an open-water certification course but just found out I am pregnant. Can I at least participate in the pool sessions? A:

There are risks inherent to all dives, even those done in the pool. Dive injuries such as arterial gas embolism (AGE) and pulmonary barotrauma can occur in water as shallow as 4 feet, and both have the potential to cause serious symptoms.

AGE (which can occur with or without pulmonary barotrauma) is characterized by the presence of gas bubbles in the arterial circulation.

DAN Medics Answer Your

Questions about Dive Medicine

B y J o h n L e e a n d M a r t y M c C a f f e r t y

44 | SUMMER 2011

RESEARCH, EDUCATION & MEDICINE // F R O M T H E M E D I C A L L I N E