asthma or not?

[HNITSUJ]

My wife is a fairly new diver. She is also an asthmatic. Her asthma is interesting because she plays softball all year and it does not induce a problem. Up until last summer she has never really been deeper than 20ft. Her only issue while diving is that she is concerned about equalizing. I have, as well as instructors, taught her how to equalize. I really believe it is in her head as she usually does very well equalizing. Last summer we did a deeper shore dive in Hawaii down to +/- 70ft. I knew we could get some depth so I was hoping she wouldn't pay much attention to the depth on her computer because I thought she may panic about her ears. We did the dive and she seemed fine, but I noticed she was watching her computer more and then she signaled that she couldn't breathe. Later she told me her chest felt heavyand that the water pressure was too high. Not taking any chances, I guided her on a very slow ascent up to 30ft where we stayed awhile to decompress. She seemed to snap out of it as soon as we ascended abit. She then proceeded back to checking out the reef. We then worked our way to 20ft and again stayed awhile. Watching her, I tend to think the depth freaked her out abit rather than an asthma attack. I have had a similar experience in very murky water down deep and found it was completely in my head. Anyone have any experience with a similar situation? I will never take a chance that its in her mind but I tend to think more experience will be the answer.

 

[DocVikingo]

Hi HNITSUJ,

Asthma can be triggered by a variety of events, including exercise, cold and very dry air, and SCUBA can involve all three of these.

If an actual asthma episode was experienced on the dive described, then these need to be ruled out as precipitants

However, as I'm sure you know, the typical asthma attack is not simply a sensation of "heaviness" in the chest region and a sensation of not being able to breathe when in fact objective observation suggests that breathing is not impaired. A diver in the throes of a bona fide asthmatic event generally would not be expected to be able to make a very slow ascent from 70' to 30', snap out of the "attack" as soon s/he ascended a bit, fin along the reef for a while and then stay a while at 20'.

Just food for thought.

Helpful?

DocVikingo

This is educational only and does not constitute or imply a doctor-patient relationship. It is not medical advice to you or any other individual, and should not be construed as such.

 

[fisherdvm]

I would wonder if her symptoms are anxiety. I know that I always have had anxiety of drowning. Ever since my older brother drowned when I was eleven, that memory sticks to me. He drowned in a gravel pit in a warm day in May. My mom has always been terrified of my drowning, so it affected me.

I swim about 3 miles a week, but in a 4 ft shallow pool, I can do 400 yrds in about 9.5 minutes. But last week, I took my divemaster swim test, and had to do 400 yrds over the deep end of the pool. I know that I was short of breath from anxiety. After 300 yrds, I had to switch to the breast stroke because I was short of breath. I always feel anxious over deep water. I was not out of shape, simply the anxiety affected my breathing.

In the same way, I wonder if your wife had a spell of anxiety.

 

[HNITSUJ]

anxiety is exactly what i was thinking

 

[shakeybrainsurgeon]

At depth, air viscosity increases as the inspired air increases in density. After a cursory web search, I found a very old article (Journal of Applied Physiology 9:5-10, 1956) which measured airway flow in people within decompression chambers. At air pressures simulating 99 feet depth, air viscosity reduced airway flow at normal inspiration by 50% in normal lungs. In other words, this is hardly a trivial effect...the feeling that it is hard to breathe at depth can be quite real, not anxiety. In people with normal airways, this reduction can be tolerated, but in people with reduced airway diameter, like an asthmatic, baseline airflow may be reduced such that it feels like they are breathing through a straw. Not a good feeling (try it, it's weird).

Furthermore, if we overlay anxiety, two things happen: 1) the person tries to inhale harder and more rapidly which, due to the airfoil effect (faster moving air has less pressure) causes the airways to collapse further) and 2) hyperventilation reduces carbon dioxide as induces a feeling of breathlessness, which aggravates the problem more. The airfoil effect can also be simulated by breathing through a paper straw...too fast and the straw collapses. With practice, you can breathe through a straw with slow, low speed and prolonged inhaltion/exhalations, but it is disturbing and exhausting.

The difficulty breathing at depth here may signify that your wife had narrow airways going into the water (even aymptomatic asthmatics may have significant airway narrowing that is not apparent clinically).

Suggestion; if she does not have a personal spirometer, get one. They are cheap and easy to use. Before diving to 2 or 3 atm of pressure, she should blow a spirometer and see what her air movement is like. If it is poor at sealevel, it isn't going to be any better when she's breathing thick, dry air. If she can use an inhaler to get it back to normal before diving, this may help.

Again, this is just my opinion, not official advice. "Officially" many doctors consider asthma and diving a dubious combination, although modern thinking is that asthamtics can, in most cases, dive safely.

 

[headsqueeze]

When SBS was posting I too was doing a search in med lit. A couple of things to add... heliox has been used in hospitals to facilitate air exchange for COPD, Asthma and other pulmonary diseases. So you have SBS's viscosity @ depth, and clinical benefit of heliox on land shown to improve diseased lung function. Is Henry's law w/ pulmonary inflammation (Asthma) important?

Trust what your wife is telling you --- "I can't breath!". She might be right and it's not worth a gamble. A personal spirometer, is a peak flow monitor (one of several parameters to understand lung function) and will get you in the ballpark. You might ask your wife to consider a pulmonary function study in a physician's office both before treadmill and after peak exercise.

In summary I would:
1. attempt clinical control of her asthma (3 months to do it right) and
2. dive the depth your wife finds fun and easy.

 

[Dive Junky]

Is she a diagnost asthmatic that is on medication?