More technical stuff re: asthma [Archive]

gsclarke

19-10-2006, 13:14

TerryH

19-10-2006, 13:28

Well I'm still reading and learning and here is my latest question(s)

If nothing has changed I know my asthma problems are confined to the upper respiratory tract. I hadn't given it much thought until now but looking at the definition of that, it suggests that the lungs themselves aren't affected.

All this of course presupposes I can actually get signed off, but I feel that if my problems are upper respiratory only, perhaps my risk factors aren't quite so high?

Any comments?

Upper and Lower Respiratory Tract.
The upper respiratory tract consists of the nose, nasal cavity, frontal sinuses, maxillary sinuses, larynx, and trachea. The upper respiratory tract carries air to and from the lungs and filters, moistens and warms air during each inhalation.
The lower respiratory tract consists of the left and right bronchi and the lungs, where the exchange of oxygen and carbon dioxide occurs during the respiratory cycle. The bronchi divide into smaller bronchioles in the lungs, the bronchioles divide into alveolar ducts, the ducts into alveolar sacs, and the sacs into alveoli. The alveolar sacs and the alveoli present about 850 square feet of space for the exchange of oxygen and carbon dioxide that occurs between the internal alveolar surface and the tiny capillaries surrounding the external alveolar wall.

Well if that's the case then it comes down to anything that might restrict
the flow and that's either a contaminent (dust house mite, pollen) or an
induced condition (cold, stress).

If it's the former then no probs. Air is filtered several times so very unlikely
to have a problem. If its the latter then you might be resigned to no diving
or at best warm-water, easy shallow stuff.

Again it's down to the Doc, but worth asking around as to what they are
like. I know one doc who wont under any circumstances look at an asthma
suffererer, while another will happily do the tests and weigh up the risk.

TerryH

PS: It might be an idea to put very roughly which area of the UK you are in
on your profile. Might get some more info on the local Docs.

gsclarke

19-10-2006, 14:05

I hope you are right Terry. I'm thinking that maybe the risk of air embolism etc. is not so high if my problems are upper respiratory only and since I don't actually have problems breathing I'm keeping my fingers crossed.

I'm confident it's not exercise induced and hopefully not cold either. I have a feeling food may play a role. I know I get a bit stuffy after dairy products. I had a lot of cheese yesterday and my peak flow, which my GP thinks will be up from 240 tomorrow after dosing me with steroids, has actually gone down a bit today.

Although it's a nuisance that it doesn't respond to medication, in some ways it's comforting to know that it's quite stable without.

MSutcliffe

19-10-2006, 18:19

gsclarke,

Your right - Asthma is a disease of the airways, not the lungs. However. that means it affects flow of gas. No flow = No breathing = No life. You need to take expert advice on your personal risk and come to a decision yourself as to the risks involved. No-one has yet worked out how to make inhalers work underwater.

The Diving doctors have spent 10 years plus studying physiology/medicine in order to be able to understand the issues involved in this - whilst I don't want to patronise your impressive desire to read about the subject yourself - it will be extremely difficult to match the udnerstanding these guys have. Please. go and see one of them!!!!

gsclarke

19-10-2006, 18:43

The Diving doctors have spent 10 years plus studying physiology/medicine in order to be able to understand the issues involved in this - whilst I don't want to patronise your impressive desire to read about the subject yourself - it will be extremely difficult to match the udnerstanding these guys have. Please. go and see one of them!!!!

I hear what you are saying but the point is:
1. Until I can get my FEV/FVC ratio to 70% they won't even see me. No point.
2. Even at 70% and passed for diving, I still want to understand what risks I run rather than just accept that I can now dive.

I don't know Dr Clamp personally although she has been very helpful on the phone. However if you have problems for years, like ME and asthma, which the medical profession haven't been able to treat, it does kind of make you want to understand a bit more about what's going on.

I'm in the fortunate position that I took BUPA cover earlier this year before I found out just how poor my lung function was. I suspect when I see Professor Pavord on Monday I will get a lot more opportunity to ask all sorts of questions that I probably wouldn't get time for on the NHS, and hopefully an answer as to exactly what my problem is before too long.

What I'd like to able to do is know what questions to ask and have enough knowledge to understand the answer. ;)

TerryH

19-10-2006, 18:48

Please. go and see one of them!!!!

Actually that's a good point.

To gsclarke .....

In

http://www.bsacforum.co.uk/forums/showpost.php?p=44943&postcount=1

You talk of matching your Instructor when diving.
How did you get past the disclaimer???????

PADI & BSAC both have a tick box system and you would have definately
fell foul of that and been asked to see a diving doc.

So what did you do?

gsclarke

19-10-2006, 18:55

PADI & BSAC both have a tick box system and you would have definately fell foul of that and been asked to see a diving doc.

So what did you do?

Don't panic - I didn't do anything naughty. ;)

I ticked all the appropriate boxes and my GP (it was a locum at the time) signed my forms to me to dive to 3 or 4 metres. When I saw I was fine (more to do with the ME than asthma since I have no breathing problem as such), I then faxed my GP for permission to go to 5 metres to complete the Padi Scuba Diver.

It was only when I got back and said I wanted to go to 18 metres to finish the open water course (2nd November) that the lung function test was done.

gsclarke

19-10-2006, 19:05

Actually I should maybe make a couple of things clear before you all think I'm lunatic that won't go to the right people.

First Dr Clamp is our local diving refereee and I am talking to her. I do need to get my ratios up before anything else though.

Second Professor Pavord at Leicester is one of the best respiratory consultants in the area and I see him Monday.

So I'm not asking you guys what you think as an alternative to seeing the right people, just that I like to hear what you all think.

Plus I'm VERY frustrated at what has developed so I guess a little of that is coming through too as I cling onto the idea that I can get this sorted in time to dive but in my heart I know it's not likely to be sorted in a couple of weeks.

Guess who's going to be a grumpy old ***** watching my husband finish his course when I'm not allowed to dive :(

MSutcliffe

19-10-2006, 23:24

Matt-75

20-10-2006, 01:16

The ultimate decision really should be your, but must be made with the full knowledge of your buddy - if he gets in trouble - and you panic - and have a panic induced asthma attack - then he dies.

And if you have a panic induced asthma attack, chances are you arent going to fair much better than your buddy.

That point really depends on how many asthma attacks you've had in the last 20 years or so. If you've had any in the last 10 years then i wouldnt risk it, but if you haven't then chances are you've adapted to that side of things. Some people outgrow the severe side of things with age and learn to deal with it before it ever becomes an issue, therefore avoiding the problem. But it isnt a catch all by any means, these things can happen at the damndest times when you least expect them.

gsclarke

20-10-2006, 08:31

(I expect to get flamed for this statement). I for one think it is time that folk stopped talking about "Medical permission to dive." It is a certificate of "Medical fitness to dive", and as I stipulate above, it is an individual doctors opinion only based upon the information available to them at the time of the assessment.

No Flaming - at least not from me. It would kind of defeat my objective if I only listened to what I wanted to hear and disregarded the rest.

You're quite right. Whilst I won't dive without getting the appropriate paperwork there is also an element of one doctor not being quite as picky a another and as I said before, the difference between a no at 69% FEV/FVC and a yes at 70%, is negligible.

I can only learn as much theory as I can and get as much info. about how I respond, and make an informed decision not only as to if I dive but how when and where.

I already know (assuming I can get past the medicals) that I will have to be aware of my limits because of ME.

...how many asthma attacks you've had in the last 20 years or so. If you've had any in the last 10 years then i wouldnt risk it

Well this is the frustrating thing. I've never had an asthma attack as such in my life. Just a 30 year old cough and a poor peak flow. 8 years ago I got a bit wheezy and stuffed up and after yet more tests with no response to medication, I took a Buteyko breathing course which was brilliant. At that point they just called it mild non-responsive upper respiratory asthma, prior to that every time time it failed to respond to inhalers and steroids they did a u-turn and said it wasn't asthma at all. Frustrating or what :mad:

This is why I'm so keen to gather as much understanding as I can. I am hopeful that with being privately funded this time, time and resources will mean a more definitive diagnosis.

On the other hand, if I can make the grade for the medical but still no clear answers as to if it is asthma etc., then I guess there is only me that can make the decision.

The ultimate decision really should be your, but must be made with the full knowledge of your buddy - if he gets in trouble - and you panic - and have a panic induced asthma attack - then he dies.
I guess that is uppermost in my mind. I made special arrangements in Egypt to do the 2 day course split over about 10 days and also for Dave and I to have an instructor to ourselves.

To be honest even then I kept looking to see if she was watching Dave. I kind of had a concern that whilst I was absolutely fine, she might worry about me and miss something if Dave was in trouble.

Our local club makes a point of splitting husband and wife so they can concentrate more without worrying about their other half.

Mike Halligan

20-10-2006, 10:06

I jsut want to point out - Medical advice is just that - ADVICE. Once you have taken all of the information, then frankly, it should be the decision of yourself AND your buddy as to wether to dive.

The paternalistic decision that it is not safe for certain groups should be considered wholly unnaceptable in this day and age.

Not flaming :)

You are right, there should be and in fact there is no 'class' ban. Everyone is welcome to complete the self-declaration and then, if appropriate, be examined by a referee. If a referee declines a "Certificate of fitness" then the subject is unlikely to be taken diving by any agency.

In our own case, members of the BSAC, it would be a foolish DO, Centre operator, Instructor or buddy who ignored the fact that a certificate has been declined. Beside the blindingly obvious, that of putting the buddy in significantly greater danger than normal whilst diving, the probability of vicarious liability for any consequence lying with buddy, Instructor, DO and/or Centre operator is raised to the n'th degree.

So, I believe that we are as inclusive as it is safe for us to be. The term 'safe' applying to all members, not only the person who approaches us wishing to dive or learn.

We need, perhaps, to cut our DOs a little slack here and recognise that they bear a heavy burden of balancing facilitation of all with safety of all. I'm sure there is no accusation in this thread and do appreciate the frustration caused when one's expectations are impeded. However, our duty of care extends beyond the individual.

Hope this helps,

Mike Halligan

gsclarke

20-10-2006, 11:54

In our own case, members of the BSAC, it would be a foolish DO, Centre operator, Instructor or buddy who ignored the fact that a certificate has been declined.

Hi Mike

It's good to hear your views and I totally agree. Even in the simplest cases it must be a tough call for a GP to sign some-one off to dive when they are borderline, especially given the inclination for people to sue at the drop of a hat nowadays, not that I would imply that is uppermost in anyones mind.

As regards declined certificates, I think (or would hope) that no-one here (me included) would even think of trying to dive if a certificate had been declined.

I've just got back from my GP and he thinks it isn't asthma as I got no steroid response. [You wouldn't believe how many times I've heard that over the years. What chance do I have of understanding if they can't make up their minds :confused: )

I have what they call a 'mild obstruction' although the nurse was fascinated at how long I could make a breath last on the tests. When I see Professor Pavord on Monday, I will ask him to spell out for me exactly what that means. Since he's being paid a healthy amount by BUPA for his services, I don't intend to leave until I understand what's happening. I hope his artistic skills are good as it may come down to him drawing diagrams so I can understand properly ;)

My GP says he's happy at 3 metres so I can do the pool work. The local club, quite rightly so, would like him to sign to that effect. To be honest I'm unclear about whether even 3 metres presents a risk. I don't suppose your average GP thinks further than the chances of an attack and a mad rush to the surface whereas even with my limited knowledge I'm thinking if the air can't get out what difference is there between 3, 5 or 10 metres. It still can't get out can it?

At that level though I equate it to when I do my lifeguarding stuff or snorkel. If I'm only spending short times at 3 metres is there a lot of difference?

Unless I hear anything to the contrary here or from Prof.Pavord on Monday, my GP will sign for 3 meters and I will content myself with that for a while. At least I can do some skills in the pool. We start the BSAC stuff Tuesday which shouldn't be too hard having done the PADI.

On another matter, it's kind of fun to see how the theory of air compression fits into a real life situation when diving at say 3, 5 or 10 metres. When I think it terms of how much extra air goes in and ergo how much has to come out, it kind of seems more real.

mmm Might start another thread to see if I've got my calculations right.

Thanks for the input everyone, Gay

TerryH

20-10-2006, 13:01

gsclarke,

(I expect to get flamed for this statement).

I jsut want to point out - Medical advice is just that - ADVICE. Once you have taken all of the information, then frankly, it should be the decision of yourself AND your buddy as to wether to dive.

The paternalistic decision that it is not safe for certain groups should be considered wholly unnaceptable in this day and age.

Admittedly - if a Dr won't sign you off, then the BSAC won't insure you (neither will any other insurer) - but if you choose to take the whole risk on personally, that's your choice.

I for one think it is time that folk stopped talking about "Medical permission to dive." It is a certificate of "Medical fitness to dive", and as I stipulate above, it is an individual doctors opinion only based upon the information available to them at the time of the assessment. The ultimate decision really should be your, but must be made with the full knowledge of your buddy - if he gets in trouble - and you panic - and have a panic induced asthma attack - then he dies.

Err no it's the decision of the DO or pro-school/guide if you dive. The only
time you can make that choice is if you go off on your ownsome.

Of course if it's on holiday then you can throw away any insurance. When
you do eventually get back then dont rely on your life insurance or medical
plans, they wont want to know. Even if you did agree with your buddy,
better get it in writing, cause post-incident the spouse will be after you big
time for lack of care and of course seeing as you flouted the most basic
of rules I dont think BSAC's insurers will be that bothered with you either!

Of course you can dive without following basic rules, but unfortunately our
financial wellbeing is conditional on us following such rules.

You'd have to be really dumb (or very selfish) to put family and friends
through such a nightmare.

T.

Gareth

20-10-2006, 15:02

Gay

Just for clarity, ignoring being asthmatic or not at this point.

If you take a full breath on the surface (lung volume = 6l)
Then you descend from the surface to 10m (easy numbers).
The ambient pressure doubles.
The lungs are compressed by the ambient pressure so the lung volume halfs (you now have 3l of air in your lungs at twice the surface pressure).

If you now ascend there is no risk to your lungs the volume will return to 6l at the surface pressure. i.e. there is no over expansion.
This is what happens when swimming or snorkelling.

If however at 10m you inhale from an aqualung.
At 10m you now have a lung full of air (6l) at the ambient pressure (twice that at the surface).
If you now ascend holding your breath, the ambient pressure will fall, the air will expand, the end result would be your lungs would expand to contain the 12l of gas. DO NOT EVER DO THIS.

The end result is overexpansion lung injuries, everything from burst lung to CAGE (Cerebrial Arterial Gas Embolism).

One of the reasons (as you already are aware) that asthmatics & others with lung / breathing problems have difficulty getting diving medicals is that you want NO IMPEDIMENT, to the air escaping from the lungs during the ascent phase.

This explaination only relates to pressure & volume, not to nitrogen or its effects.

Final note.
This is why its not recommended for untrained snorkellers to swim down to Scuba divers & take a breath of the DV prior to ascending!
This is why in the dive briefing you are always told NEVER HOLD YOUR BREATH ON AN ASCENT WHILST USING AN AQUALUNG!

Gareth

MSutcliffe

22-10-2006, 19:27

TerryH

The BSAC have decided upon a policy of exclusion - they define a minimum medical standard and stick to it. There is, apparently, no room for personal decision making.

I think this is absolutely and completely wrong.

It is attitudes like this which mean that the decision making is taken away from the individual, and how can that be right.

gsclarke - I, personally, would be happy to dive with you as your buddy if, after discussion with appropriately qualified indivuduals, you decided that the risk was a reasonable one for you to take. Obviously, if you don't meet the minimum standards medical standards laid down by the BSAC, then it owuld have to be outwith the BSAC and outwith any other formal organisation - but then that's OK, because There is no law in the UK which prevents you from walking into a shop and buying the kit, nor is there a law which says you need a qualification to go diving.

Adrian Kelland

22-10-2006, 19:48

The BSAC have decided upon a policy of exclusion - they define a minimum medical standard and stick to it. There is, apparently, no room for personal decision making.
The BSAC use the UKSDMC advice. To not do so has the potential to open all kinds of problems regarding negligence.

As to personal decision, this is not just about the person with a condition, but any buddy too. Hazard, risk, mitigation and all that. Which is why we have the referee system to review individual cases.

Adrian

gsclarke

22-10-2006, 20:03

The BSAC have decided upon a policy of exclusion - they define a minimum medical standard and stick to it. There is, apparently, no room for personal decision making.

I think this is absolutely and completely wrong.

It is attitudes like this which mean that the decision making is taken away from the individual, and how can that be right.
In some ways I think you are right and ultimately there should be SOME leeway for personal choice. As I said in another thread, everyone's attitude to risk is different.

Also the world is full of anomolies. We are made to wear seat belts (and yes I do wear mine;) ) but allowed to smoke 60 fags a day in the same room as our babies or go and blow all our wages at the bookmakers leaving our kids eating bread and jam. Just picking those 2 as examples re. the financial risk as well as a health risk.

I suppose I sit on the fence with this but if I had to choose I would say there would be much to be said for some-one being 'advised' against diving being allowed to sign a disclaimer with the proviso that they weren't endangering anyone else. (I'm thinking more of Dive Centres here, certainly the ones I've come into contact with have never mentioned anything other than you MUST be signed off if you have any health issues.)

For example, once I have all the facts, if I decide to dive being OK'd at 70% FEV1/FVC but a year later it drops to 69%, I would really like to make my own decision on something that borderline.

gsclarke - I, personally, would be happy to dive with you as your buddy if, after discussion with appropriately qualified indivuduals, you decided that the risk was a reasonable one for you to take. Obviously, if you don't meet the minimum standards medical standards laid down by the BSAC, then it owuld have to be outwith the BSAC and outwith any other formal organisation - but then that's OK, because There is no law in the UK which prevents you from walking into a shop and buying the kit, nor is there a law which says you need a qualification to go diving.
Thanks for that comment. (If my hubby decides I'm too big a risk I'll drop you a line. How old are you? I'm 54 - I could do with a toy boy :cool: Just kidding)

gsclarke

22-10-2006, 20:31

One of the reasons (as you already are aware) that asthmatics & others with lung / breathing problems have difficulty getting diving medicals is that you want NO IMPEDIMENT, to the air escaping from the lungs during the ascent phase. ...... This is why its not recommended for untrained snorkellers to swim down to Scuba divers & take a breath of the DV prior to ascending! This is why in the dive briefing you are always told NEVER HOLD YOUR BREATH ON AN ASCENT WHILST USING AN AQUALUNG!
I hear what you are saying, but leaving aside the issue of an untrained person or diver in a panic holding their breath, I previously thought the risk was no different for an asthmatic (or any-one where breathing blockages may occur, even a simple cold) when diving at 3 or 4 metres in full gear or diving to that depth when snorkelling or doing life-saving skills in a 3 metre pool.

From discussions on this forum, I understand that the air compresses instantly.

However thinking about it properly, of course the snorkeller or swimmer has no opportunity to take the extra air into the lungs so it is quite different.

I have a feeling my GP hasn't quite taken this on board when he says I'm fine doing my diving skills in the pool but not the sea. I was going to ask why I couldn't do them in the sea but I think I may be asking the wrong question there.

Hopefully when I see Prof.Pavord I will get the opportunity to try and understand just how dangerous it would be, for example, to take on an extra 20%, 30% air etc. and have difficulty releasing it. Also the question of severity of blockage of course.

Talking totally theoretically now, if I have a lung capacity of 6 litres and dive to a depth where I take on two extra litres and struggle expelling half of it, it's possible he will say at this level it's would be unpleasant but not major or fatal - or I would have to have a real bad attack to be so blocked that this would be dangerous - or that it was unlikley I could have an attack bad enough to cause a major problem without being aware of it and ascending before it became an issue.

These are the sort of things I would like to understand more about rather than rely on a black and white cut off point of 70%FEV/FVC.

There is also the question of people who have been signed off to dive providing they haven't needed inhalers or wheezed in the last last x hours.

Just how indicative of a potential attack is that? Just because you've been clear this week says absolutely nothing about next surely?

TerryH

23-10-2006, 19:57

The BSAC have decided upon a policy of exclusion - they define a minimum medical standard and stick to it. There is, apparently, no room for personal decision making.

I think this is absolutely and completely wrong.[/B]

Yes you are right, it is absolutely and completely wrong. BSAC dont have
a policy of exclusion, they have a policy of refferal. It is the UKSDMC that
draws the line and decides when to exclude.

It is attitudes like this which mean that the decision making is taken away from the individual, and how can that be right.[/B]

I find in incredulous that a Doctor would even question this. You above all
people know that in almost every arena Doctors do not self-certify.
However in a situation where not only a buddy, but lives of a rescue team,
RNLI and coastguard/helo may be put at risk, it is apparently ok for an
individual to make that choice?????????

T.

Mike Halligan

23-10-2006, 20:19

The BSAC have decided upon a policy of exclusion - they define a minimum medical standard and stick to it. There is, apparently, no room for personal decision making.

The BSAC, along with SSAC and SAA, accepted the advice of the UKSDMC and adopted that organisation's self-declaration and medical referee system.
This is not medical exclusion but conscious, responsible setting of a reasonable target.

Neither is this social exclusion. The BSAC accepts anyone who can provide a satisfactory self-declaration or referee's certificate. From that point, we work with members to accommodate disability and provide them with the best advice, instruction and support.

In the fulness of time, a Branch DO must decide how to manage dives (taking account of the circumstances of the Branch) and thus needs a reliable datum from which to judge. The UKSDMC system provides precisely that. Within the BSAC, it is not for one individual to deliberately place another's life in danger. In each instance, medical target, disablity provision and dive management, I believe that the BSAC is behaving entirely inclusively.

Mike Halligan