Search
Related Links

 

 

Informative Articles

Health - Top Herbal Supplements
Top Herb Supplements Sold in America Every year millions of people try and use herbal supplements. Herbal supplements are big business bringing in millions of dollars each year. Herbal supplements are usually not regulated by the government...

Help Your Immune System Fight Diseases With Natural Health Medicine
The benefits of taking care of yourself are some of the rewards you get from knowing that you are doing the best for your body. This includes the most important part of your body--the part which is in fact a mechanism that protects your body:...

History of Plastic Surgery
An Original Article Written By Owner and Webmaster of PlasticSurgeryOrg.com Charles Kassotis When most people use the term Plastic Surgery they more often than not use it in reference to cosmetic surgery. Few people actually stop to think that...

"THE 3RD BIGGEST CAUSE OF DEATH!"
It will surprise you! Did you know that if you become ill and you put yourself in the hands of 'mainstream' medical care and need to be admitted to a hospital that the chances of you dying from an unrelated problem are high? In fact, in the...

The Secret to a Happy Life
There seems to be an epidemic these days of depression. Everyone I talk to, it is experiencing some degree of depression. As I wonder about the cause of this twenty-first century phenomenon, I think of my great grandmother who raised my dad in the...

 
Diving with Asthma

Many asthmatics want to dive, but unfortunately, there are a number of concerns about the effect of asthma on dive safety. Dive physicians have traditionally taken a very conservative approach to asthma in dive fitness assessments. Mention of the word "Asthma" and potential divers were ejected from the surgery faster than you could say, "but it wasn't serious and it's gone away now"

More recently, some dive physicians have begun to take a more liberal, informed consent approach in assessing previous or mild asthmatics for diving. Some ex-sufferers previously prevented from diving can now dive, after making an informed choice about the possible risks. To understand this, it is first necessary to understand what asthma actually is. Asthma is a condition affecting medium to small airways in the lungs. In asthmatics, these airways are prone to narrowing, which impedes the flow of air into and, in particular, out of the small air sacs (alveoli) where gas exchange occurs. The trigger for these events is often an allergic response to a specific stimulus.

Some asthmatics also respond to physical stimuli such as exercise or a change from breathing warm air to cold air. The result is that the patient feels short of breath and there may be an audible wheeze due to airway narrowing which can cause severe breathing difficulty, which in severe cases, can certainly be fatal. One of the biggest problems in discussing asthma, and this is particularly true when discussing asthma in the context of diving, is that the spectrum of severity is extraordinarily wide.

There are three main concerns about asthma and diving. First, asthma may make divers more likely to suffer a dive-related illness. We are all taught that the most important rule in diving is to breathe normally and to never hold your breath. If a diver ascends while holding his breath, the expanding air can damage delicate lung tissue, and air may be introduced directly into the blood, travel to the brain and cause an arterial gas embolism (AGE).

There is concern that an asthmatic may suffer narrowing or blocking of small airways during a dive, and that expansion of any trapped air during ascent may lead to the same problem. There is also concern that use of reliever medication, such as Ventolin, prior to diving may cause the lungs to be less efficient at filtering out the venous nitrogen bubbles we all have after dives. These bubbles may then circulate through the lungs and reach arteries where they might, in theory, be more likely to contribute to the development of decompression illness.

Second, it is recognised that an asthma attack in the water may severely compromise the diver's safety by incapacitating him and causing an inability to function effectively. Indeed, it is hard to argue that difficulty breathing would not be a decided disadvantage if you were caught in a current that was sweeping you away from your boat.

Third, it is a plausible concern that diving itself could precipitate asthma. Asthma can be precipitated by the exercise associated with diving, or by the irritant effect of breathing a cold, dry gas. It is also recognised that regulators frequently leak a little salt water, and that some of this may be nebulised into a mist during breathing. This mist can irritate the airways and precipitate narrowing in vulnerable individuals.

The problem with all these very plausible concerns is that we have no idea how truly significant they are as there has been very little historic research. There is some data from retrospective surveys and these reveal many asthmatics (including active asthmatics) do dive, and that while their relative risk in diving may be more, their absolute risk remains reasonably low. e.g. one survey indicated that


asthmatic is twice as likely to suffer an AGE as a non-asthmatic. Sound bad? Maybe. But if the risk of AGE for a non-asthmatic is one in every 50,000 dives, then the risk for an asthmatic is one in 25,000; a clear illustration of the fact that not very much multiplied by two is still not very much.

In this day and age where people do not want to take responsibility for their own actions, the most prudent thing for a dive physician to do when an asthmatic walks into his surgery is to say "Bog off, you're unfit". This happens frequently, and who can blame the doctors? However, while it might be defensive medicine, it is not necessarily good medicine. Indeed, such subjective pronouncements often motivate the candidate to go to another doctor and lie about having asthma.

There is now an alternative informed consent basis of assessment. Fundamentally, this means clearly and comprehensively explaining the risks of diving to the candidate, and letting him make an informed choice about whether to proceed. However, there are some important provisos. In the context of asthma, most dive physicians would agree that the more active the asthma, the greater the risk in diving. Those candidates who suffer serious attacks, wheeze relatively often or who use reliever medications regularly, cannot be considered for diving, even on an informed consent basis, because rightly or wrongly, the risks are perceived to be too high.

On the other hand, previous asthmatics and milder cases may be subject to little extra risk, and it is reasonable to let them, as intelligent adults, make up their own minds on the matter. Every day of our lives we make decisions that inherently involve weighing risk against benefit. We choose to get on planes, we choose to play rugby, we choose to ride bicycles on busy roads, all because we decide the benefit outweighs the risk. There is no reason diving should be any different in this regard, although dive candidates are much less well-informed about its inherent risks than they are about these other intuitively obvious risk situations. It is the dive physician's role in this setting to sufficiently educate candidates so they can make an informed choice.

A sensible approach to the asthmatic dive candidate is to first take a detailed history of his problem. The obvious active asthmatics are told they cannot dive, and the reasons are clearly explained. Asthmatics who have not experienced symptoms of asthma or have not used medication for years are usually able to dive without any special investigations.

The most problematic are mild asthmatics i.e. those candidates who wheeze once or twice a year when they have colds; or who wheeze a little in the spring when certain pollens are around, etc. With these candidates, a long discussion about the potential risks in diving implied by their asthmatic history, is usually followed with tests to check that neither exercise nor the breathing of nebulised salt water (at the same concentration as sea water) provoke airway narrowing. If these tests are negative and patients exhibit a clear understanding of the issues and wish to proceed, then we should be happy for them to dive. Unfortunately, to conduct and document this process properly is a time consuming and expensive exercise, but at least it's better than being told to "clear off" without so much as an explanation.

About the Author

Sheldon Hey is the founder of Dive The World (http://www.DiveTheWorldThailand.com)and has been an passionate scuba diving professional for many years. Sheldon and the Dive The World Team would love to share their experience with you to ensure your next diving trip meets all your expectations. Follow this link if you would like to read more about Sheldon’s scuba diving experiences.

 

National Library of Medicine - National Institutes of Health
Part of the National Institutes of Health, the National Library of Medicine offers access to health information for consumer, patient, and physicians ...
www.nlm.nih.gov
 
Health and Medical Information produced by doctors - MedicineNet.com
Doctor-produced health and medical information written for you to make informed decisions about your health concerns.
www.medicinenet.com
 
Medicine in the Yahoo! Directory
Collection of sites for health professionals, with sections on specific disciplines, organizations, continuing education, conferences, publications, ...
dir.yahoo.com
 
MedlinePlus Health Information from the National Library of Medicine
Health information from the National Library of Medicine. Easy access to Medline and Health topics, medical dictionaries, directories and publications.
medlineplus.gov
 
Medicine - Wikipedia, the free encyclopedia
Medicine is a branch of health science and the sector of public life ... The practice of medicine combines both science as the evidence base and art in the ...
en.wikipedia.org
 
Journal Home - Nature Medicine
Nature Medicine has a vacancy for a Locum Assistant Editor for six months. The position involves working in all aspects of the editorial process, ...
www.nature.com
 
The New England Journal of Medicine: Research & Review Articles on ...
The New England Journal of Medicine (NEJM) is a weekly general medical journal that publishes new medical research findings, review articles, and editorial ...
content.nejm.org
 
eMedicine Clinical Knowledge Base
eMedicine features up-to-date, searchable, peer-reviewed medical journals, online physician reference textbooks, and a full-text article database in 62 ...
www.emedicine.com
 
Open Directory - Health: Medicine
the entire directory, only in Health/Medicine. Top: Health: Medicine (11429). Description · Medical Specialties (4888); Surgery (2265) ...
dmoz.org
 
the www virtual library biosciences medicine
www.ohsu.edu/cliniweb/wwwvl/ - Similar pages
 
Medicine - home
Bimonthly journal covering the latest results in clinical investigation relevant to hospital and office practice.
www.md-journal.com
 
Institute of Medicine
The Institute of Medicine serves as adviser to the nation to improve health.
www.iom.edu
 
ScienceDaily: Health & Medicine News
Medical Research News. Health news on everything from cancer to nutrition. Full-text, images, updated daily.
www.sciencedaily.com
 
Google Directory - Health > Medicine
Search only in Medicine Search the Web. Medicine. Health > Medicine, Go to Directory Home. Categories. Alternative Medicine (6308) Basic Sciences (66) ...
www.google.com
 
the world wide web virtual library biosciences medicine
www.mcb.harvard.edu/biopages/medicine.html - Similar pages
 
PLoS Medicine - A Peer-Reviewed Open-Access Journal
PLoS Medicine is a peer-reviewed, international, open-access journal published ... Every issue of PLoS Medicine contains a selection of readers' responses. ...
medicine.plosjournals.org
 
Medicine On-Line - Medicine Online -The International Medical Journal
Medicine Online - independent and peer reviewed journal published by Priory Medical Journals - priory.com.
www.priory.com
 
Entrez PubMed
PubMed is a service of the US National Library of Medicine that includes over 16 million citations from MEDLINE and other life science journals for ...
www.ncbi.nlm.nih.gov
 
Stanford University School of Medicine
Home Page of the Stanford University School of Medicine.
med.stanford.edu
 
Medicine OnLine
Meds.com offers medical information and education on cancer (lung cancer, colon cancer, breast cancer, leukemia) and HIV / AIDS for patients, ...
www.meds.com