Asthma and scuba,

Scuba Diving with Asthma

People with asthma can lead active lives, but they may have to take special precautions when engaging in particular activities -- including scuba diving.

Asthma and Physical Activity
Asthma is a chronic inflammatory lung disease. The inflammation of the airways can trap air deep within the lungs, resulting in their over-expansion. However, there are numerous asthma medications available to treat this inflammation and air-trapping. Many national and international organizations that publish asthma treatment guidelines stress that people with asthma should be able to lead active, healthy normal lives, including participating in many different sports and activities.
Asthma and Scuba Diving
Scuba diving has long been a popular recreational activity, with over 5 million certified divers in the United States and hundreds of thousands of people becoming newly certified every year. As asthma occurs in 5 to 10% of the population, many of these divers have asthma. In the recent past, however, people with asthma were told not to scuba dive due to the mostly theoretical dangers that are present.

People with asthma would seem to be more prone to accidents from scuba diving. Many asthmatics have air trapped in their lungs, which can expand during ascent to the surface, causing the airways within the lungs to to rupture (barotrauma). If barotrauma occurs within the lungs, air can get into the blood vessels, forming an air bubble that can lodge in the brain or other organs. This is called an air embolism.

Asthma attacks during scuba diving also seem likely, given that many people have worsening asthma symptoms during exercise, such as with scuba diving. In addition, scuba divers breath cold, dry, compressed air, which can cause worsening symptoms in asthmatics. An asthmatic who is scuba diving at significant depths could not possibly use a rescue inhaler for a long period of time until ascent to the surface was accomplished, which could theoretically make an asthma attack worse for the above reasons.

Aspiring scuba divers need a doctor’s medical clearance before becoming certified to scuba dive. Many doctors, or dive instructors, have been reluctant to allow asthmatics to scuba dive, mostly based on theoretical concerns. However, studies on scuba diving accidents have not shown that asthmatics are at an increased risk for injuries. This may be because people with significant asthma may choose not to scuba dive because the activity causes an increase in asthma symptoms.

Guidelines for Scuba Diving If You Have Asthma
Despite data not showing that asthmatics are at a significant increased risk for diving injuries, many diving medicine authorities recommend that asthmatics follow special guidelines:

•People with past or present asthma should see a doctor familiar with the risks of asthma in scuba diving for a complete physical examination and spirometry.

•Scuba divers should have normal spirometry at rest, and in response to an exercise challenge which can be performed in a doctor’s office. Those with abnormal spirometry at rest, in response to exercise, or those who experience asthma symptoms with cold/dry air exposure should not dive.

•Asthma should be controlled with medications before a person participates in scuba diving.

•A person should not scuba dive if he is experiencing an increase in asthma symptoms, or if he has needed to use a rescue inhaler in the past few days prior to a planned dive.
It would therefore seem reasonable for a well-controlled asthmatic, with normal spirometry and without the need for frequent rescue inhaler use, to participate in scuba diving. It is important for asthmatics to be aware of the possible increased risk for injuries during scuba diving, which could potentially be life-threatening, and to discuss these risks with their doctor.

Asthmatic scuba divers should have frequent, routine doctor visits with spirometry performed to ensure that their asthma is well-controlled prior to diving. It would also seem reasonable for an asthmatic to use a rescue inhaler approximately 30 minutes before diving as a preventative measure against asthma symptoms, just as many asthmatics do before other forms of exercise.

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