Dive Medical Questions

What an interesting set of opinions.

Firstly let me state that in all of my years ( the last 25 ) involvement in the Diving Industry I have never been pressured by an employer or operator and have never pressured any one else on this matter in spite of the financial consequence of that come from denying a diver - lost income which can be real tough if it's in the quiet time.

Once the dreaded box has been ticked - you need to follow the process through to completetion and accept the outcome.

They must visit a hyperbaric specialist for clearance to dive. It's easy in Cairns as there are about 10 of them here.

It is never a pleasant thing to tell someone who has their heart set on doing a course, or completing an introductory dive that they need medical clearance.

Never pleasant to be questioned what would you know ........... I travelled around the world to do this ............. You have ruined my holiday ............. I 'll tell every one about you and you second rate...............

All these things have been said many times in the past and will continue.

I would ask people to think about the unpleasant side asthma induced salt water aspiration .

Consider the first responder - it's never pleasant for him even with a successful outcome. Never pleasant for the other people out having a day's diving. Never pleasnt for any person involved and that is with a positive outcome.

What about the worst case - a life changing experience for the victim ( dead ), , fine you might say, what about the people involved in trying to save the person.................. what about their buddy ...........

I think that some people are less suited to diving than others, and that some people just shouldn't dive.

Let the Hyperbaric specialist's decide on an individual basis.

Here a few notes on the subject.

South Pacific Medical Society - Workshop on Asthma.

Introduction

The Society's workshop on asthma and diving was held as part of the 1995 Annual Scientific Meeting at Castaway Island, Fiji. The open forum component of the workshop was prefaced by a series of presentations (a single written submission was received from Dr Douglas Walker) which are published in this issue of the Journal.

Considerable consensus was apparent from these presentations. In particular, it was clear that there are few controlled data on which to base risk assessments for asthmatics who dive (let alone a consistent definition of asthma) and that some data sets (e.g. BSAC survey) were of little or no value (at the least being rich in selection bias).

Drs Fred Bove and Andy Veale agreed that what data did exist suggested that the relative risk for those asthmatics who dived was about twice that of the non-asthmatic population (not withstanding the observation that these data did not reach statistical significance) and that it was important to remember that this was in effect a doubling of a very low rate of injury and illness.

Dr Sandra Anderson described various provocation tests and in particular, exercise and hypertonic saline challenges. The most interesting aspect of her presentation was the report that regular budesonide (Pulmicort) inhalation eliminated the hyperresponsiveness in many asthmatic patients. The fitness of such a patient to dive is obviously difficult to determine. It is noteworthy in this context that the Undersea and Hyperbaric Medical Society (UHMS) has just conducted a similar workshop and it was agreed at this forum that asthmatics who are well-controlled (i.e. not responsive to exercise or salt water) on inhaled steroids are "fit for recreational diving".

The utility of provocation testing was also discussed in their presentations by Drs Cathy Meehan, Graham Simpson, Peter Chapman-Smith and Robyn Walker. Despite the differences in approach, it was clear that there was a significant false negative rate in asthmatics (and especially those on regular steroid medication). Again, it is worth mentioning the UHMS Workshop, at which there was considerable support for exercise as the primary form of provocation testing (remembering that inhalation of hypertonic saline is a "model" of exercise-induced asthma).

SPUMS policy statement on the prevalence of asthma in Australasian diving candidates

1 A history of asthma is common in diving candidates.2 The assessment of risk for a diving candidate with a history of asthma should be conducted by a medical practitioner who has had training in diving medicine (i.e. suitable for admission to the SPUMS list).

SPUMS policy on the importance of asthma in diving

1 Asthma is a potential cause of morbidity and mortality in divers. The level of risk in this context needs to be measured.2 Diving may precipitate (an) asthma (attack).3 Asthmatics may have limited exercise capacity and are at risk of shortness of breath, panic and drowning on the water surface.4 Asthmatics who dive may be a self-selected (i.e. survivor) population and hence their experience may not be representative of the risks of diving for the general asthmatic population.5 Current information (from descriptive databases) suggests that the relative risk for asthmatics who dive (compared with non-asthmatics) for a decompression illness is about 2.

SPUMS policy on the assessment of risk for a diving candidate with a history of asthma.

1 The determination of risk for diving in someone with a history of asthma requires a gradation of the severity and currency of their asthma.2 Risk stratification for someone with a history of asthma who wishes to dive will require a thorough history and examination and often lung function testing, which may include provocation testing (and especially with exercise and/or hypertonic saline). This may need to be repeated if the person elects to dive.3 Provocation testing with exercise and/or hypertonic saline (rather than with histamine and methacholine) may be more specific for asthma that is of concern in diving. The significance of a positive result is more easily understood by the diver.4 As the risk for diving in someone with a history of asthma is uncertain, permanent records should be retained as part of a SPUMS-sponsored study.

Bvanant, it does appear that in the US it's up to your personal physician to decide. They're likely to follow the DAN guidelines as it's a US-based organisation. For asthma, DAN guideline will allow you to dive in some circumstances. There's significant country to country variation, however. According to the DAN site, UK is the most lax and Australia the most stringent when it comes to asthma, although as I've noted the French appear to consider it an absolute contraindication.

Giles asks:

"And what does your personal Physician know about diving !!

it works both ways when you say a divemaster doesn't know medicine."

Maybe a little, maybe a lot. I note the DAN course in is Little Cayman, and involves a two tank dive every afternoon. It sounds like fun! Australian docs are supposed to attend a 5 day course to become official SPUMS docs. As the MJA study shows, there's little consistency amongst dive docs when presented with the same case, despite this (fairly limited) training.

The problem in making dive fitness assessments again comes down to the evidence on which to make the assessments. The UHMS and SPUMS guidelines are expert opinion, which in medical parlance is called 'Level 5 Evidence'. Here's a hint - on the scale of 1 to 5, this is not the best sort. In the case of the SPUMS guidelines, I note it's a bunch of guys getting together in Fiji:

"Considerable consensus was apparent from these presentations. In particular, it was clear that there are few controlled data on which to base risk assessments for asthmatics who dive (let alone a consistent definition of asthma) and that some data sets (e.g. BSAC survey) were of little or no value (at the least being rich in selection bias). '

"Drs Fred Bove and Andy Veale agreed that what data did exist suggested that the relative risk for those asthmatics who dived was about twice that of the non-asthmatic population (not withstanding the observation that these data did not reach statistical significance) "

ie. "We don't really have any data at all on which to base this guideline."

I've decided that this thread - as the expert opinion of a group of divemasters, divers and physicians - should be elevated to the status of "Level 5 Evidence", and in future the WETPIXEL Expert Panel Consensus Guidelines for Diving with Asthma and Dodgy Ears (WEPCGDADE, but I'm working on a cooler sounding acronym) will hopefully be mentioned in dive medicine journals along with the the SPUMS, UHMS and BSAC efforts.

Allow me to make an incidental observation:

I have been amazed at the difference in "asthma" between the US and Australia. I know that asthma represents a spectrum of reactive airway diseases, but it seems that the threshold at which someone is described as "asthmatic" differs greatly between the two countries.

It seems to me that many many people over here (meaning the US, and in Eurpoe as well) have a seasonal, fairly mild bronchospasm disorder that causes mild shortness of breath. And they call this asthma (or seasonal asthma). There is also a huge number of people here who have "seasonal allergies", particularly in the south (where I live, and have developed "seasonal allergies", much to my chagrin).

Things may have changed from when I was a young aussie, but the asthma kids always used to be way sicker than the asthmatics I meet nowadays. I think that the Australian environment tends to provide less of an allergen load than the US, and the lower severity "asthmas"/allergic reactive airway diseases just aren't seen as much in Oz. So when we hear someone say they have asthma, we think of the weedy kid in the back of the bus going blue and dying because someone stole his ventolin inhaler, when the person actually has mild shortness of breath during the late spring early summer...

Of course, I'm just a disreputable veterinary gastroenterologist, and my observations should be taken as just that :wink:

EDIT: After I posted this, I looked more closely at Whitey's post above, and see that the experts seem to think the same thing...

"Considerable consensus was apparent from these presentations. In particular, it was clear that there are few controlled data on which to base risk assessments for asthmatics who dive (let alone a consistent definition of asthma) and that some data sets (e.g. BSAC survey) were of little or no value (at the least being rich in selection bias). '

 

"Drs Fred Bove and Andy Veale agreed that what data did exist suggested that the relative risk for those asthmatics who dived was about twice that of the non-asthmatic population (not withstanding the observation that these data did not reach statistical significance) "    

(not withstanding the observation that these data did not reach statistical significance) ROFL I wish I could write back to editors sometimes and say "But I am Dr Craig Ruaux BVSc PhD MRCVS MACVSc DiplECVCP and thus you should accept what I say, not withstanding the observation that these data did not reach statistical significance. That would be sweeeeeet.

Not to get too involved with the experts and doctors here, that's not my area of expertise. Just a quick mention of several troubling aspects to this issue from an instructors viewpoint that I have personally witnessed.

Parents have a moral obligation to protect their children from hazards they may not understand. In the US, parents review and sign a medical waiver with their kids, a doctors physical is not required unless a customer answers "YES" to a pre-existing medical condition listed on the form. I have seen numerous examples of parents improperly filling out forms and intentionally denying knowledge of existing medical conditions in order for their kids to participate in diving. These conditions included asthma, heart problems, blood, brain and mental disorders in adition to the more usual "My son just turned 12 last week" when he actually just turned 8. Parents all seem to think that their kids are bigger, stronger, smarter and healthier than other kids and therefore the normal rules just don't apply to them, regardless of the risks involved. The only qualified person who is able to judge the health of candidate to dive is a professional physician with knowledge and training specific to asthma and diving. In Mexico our shop refered candidates to a local asthma specialist and diver whom we supplied with related medical medical books from DAN, a signed note from the hotel's house doctor "This person Jon Doe etc is OK to dive" would not be suficient. This is why instructors should help their students by A. Finding a local specialist to refer your students to. B. Calling the physician and setting up the apointment for their students needing medical clearance. C. Providing the physician with the needed RSTC medical clearance guidlines and forms, and D. Follow up with a call to the physicians office and ask to have the clearance form faxed back to the dive shop directly. This prevents the student or their parents from signing the form themselves (which I have also had happen to me).

Proper medical oversight of the diving business protects our students, shops, ourselves, and the diving business as a whole. Even a small dive center pays thousands of dollars per year in liability insurrance for their stores, staff, and boat operations. Failure to properly utilize established industry protocols (forms, medical clearance) hurts all dive profesionals by raising our liability rates and by telling the general public that we are irresponsible and do not care about our students and our industry.

Douglas Kaufman

PADI Course Director CD-31169

Giles: Actually, my personal physician is a diver and has spent at least one year sabbatical at Duke with the DAN guys. Your recommendation that you tell people the risks and let them decide is OK only if you think the people who are making the decisions are capable of understanding the risks which in most cases they are not. We make medical devices for a living and you would be surprised at what people will do with things even though we try to explain to them as best we can how to use the things. I would suggest that most folks do not have the slightest ability to understand relative risks (this is well published) and that allowing divemasters to make medical decisions about disease states is ludicrous. Maybe all docs are not capable of understanding the vagaries of diving but most divemasters that I have met are equally incapable of making medical judgements.

Bill