Asthma

Question:
Can you please give me some information on the situation for Asthmatics who wish to dive. I do not have bad asthma, but would be happier if I knew more about the situation. I am due to have a Spirometry test done by my GP as suggested by some PADI documentation I saw. What is the next step, as my GP is not sure. Do I have to go and see a specialist or can I be confident if I get a certain reading from this spirometry test. Do I need to have any other tests done?

Answers:
A simple spirometry would not be enough. The current practice is to consider asthma a relative contraindication to diving. Especially so if it is of allergic origin.
Normal Pulmonary Function at the time of the dive is the key, but it is necessary to exclude the possibility of asthma attacks due to stress (emotional or physical) or cold air breathing.
In general asthmatics can dive, when they are symptom free and the PF tests are close to normality. Strong bronchial reaction to stress or cold air breathing should be a matter of more caution.
DCI and Pulmonary Barotrauma risk in asthmatics is considered to be 2 - 5 times higher than in non asthmatics.
Consider these matters carefully with your GP in order to take an informed decision about your future diving activities.

Question:
I have a guest who has asthma, but is very keen on diving, so I thought I'd ask your opinion.
He uses Becotide 200 micrograms twice a day, and ventolin 100 micrograms at night. He says that it is only dust and bed mites that gets his chest tight, and that he works out everyday in the gym, with no asthmatic effects.Would it be advisable for him to dive or not ?

Answer:
From what you say, it would seem one of the asthmatic cases for which diving could be considered, with caution and only is absolutely symptom-free before diving. The fact that asthma is not stress generated is important and positive.
To be on the safe side, many such divers use to take a "puff" just before the dive, while continuing any other therapy...
However extreme attention should be paid to the risk of pulmonary barotrauma and very slow ascent must be the rule, avoiding ANY fast ascent, including ANY yo-yo diving.

Question:
I am a padi instructor and have been asked to find out about tests and reccomendations regarding asthmatics and diving.
I am led to beleive that there are specific allergy tests(dry air, salt water on air etc.)for defining the suitability of a person for diving or not diving as the case may be.
Could you please let me have further information on this subject and also where these tests can be carried out in the U.K. and the approximate cost involved.
The person concerned is a close freind and has wanted to learn to dive since childhood and while I would hate them to miss out on the experience safety is the primary concern.

Answer:
Asthma and diving is still under investigation and DAN is one of the organisations active in the research field.
At present the recommendation is that persons with active asthma should not dive.
Individuals with a history of the condition (other than childhood only who should be able to dive normally) should consult a pulmonary specialist experienced with diving who may decide to carry out a number of challenge tests such as that of nebulised saline, cold air, exercise and histamine/metacoline to see if there is any alteration is respiratory function.

Question:
I am writing to enquire about the dangers of asthma relating to diving.
I have recently been in touch with 'Asian Adventures', a diving company offering courses in Phuket, Thailand. They have suggested I contact you with my concerns. I am an asthmatic and would very much like to learn diving, in late November in Phuket. However, I have heard there have been cases when asthmatics who have been diving have got onto aeroplanes and died relating to their condition. Is it therefore safe for me to proceed to learn diving? Would it be best for me to see the doctor? I would be grateful if you could offer any advice on this matter, as well as, help to find reputable companies. I figure that provision of detailed itinerary is a key indicator of a good company, such as timing etc.

Answer:
Individuals with asthma have a propensity for the airways to constrict excessively in response to various stimuli, such as smoke, pollen, cold air, inhalation of water droplets or exercise. When the bronchi constrict, the resistance to the flow of gas increases, and gas flow is reduced, particularly during exhalation. In divers, this is compounded by the increase in density of the breathing gas. For example, at a depth of 10 meters, the breathing gas density is twice as high as at the surface. During ascent, a diver with asthma may not exhale alveolar gas rapidly enough. The remaining gas can expand and possibly rupture the alveolar wall, forcing gas into the blood vessels - AGE.

 

A gas embolism does not occur with every individual who has asthma. A conference held under the auspices of the Undersea and Hyperbaric Medical Society in April 1995 - called "Are Asthmatics Fit to Dive?"* - concluded that if a person with asthma has a normal breathing test before and after a provocative maneuver such as exercise, then the risk of gas embolism or pneumothorax is low.

 

Asthma and diving is still under investigation and DAN is one of the organisations active in the research field. At present the recommendation is that persons with active asthma should not dive. Individuals with a history of the condition (other than childhood only who should be able to dive normally) should consult a pulmonary specialist experienced with diving who may decide to carry out a number of challenge tests such as that of nebulised saline, cold air, exercise and histamine/metacoline to see if there is any alteration is respiratory function.