Feelling sick after diving...

[gregt]

Thanks for taking the time to do that assessment, but I have to disagree.

There are far too many factors to use a software model to "completely rule out DCS". The old rule GIGO applies. You do not have enough data to properly make that statement, IMO.

You may be able to conclude that DCS is 99.9% unlikely, and your information is most certainly interesting, but you simply cannot rule it out without having more information than has been provided.

If you enter the numbers into a computer it can be proven that a 5 min mile is impossible. Much like Lance Armstrong somehow produces less lactate than a normal person, making his virtually impossible uphill climbs (according to the computer models) possible, you simply cannot know how the tissues of a given person may react by using a software model.

[luminary]

Originally posted by Tech Diver
In conclusion, we can completely rule out DCS as a cause of Condor's physical discomfort.

I think we had all pretty much agreed to that before hand, but thanks for doing the actual computations. It was very interesting (I was hoping someone might do something like that!)

My point was, that newer divers with a lack of understanding of how the effects of nitrogen absorption can accumulate may come away from this discussion with "I can never get bent from a 35ft/45min dive", and that's just not the case. If you way blow your no deco limits on a prior dive you certainly could get hit. Or if you exceed your maximum daily exposure. Or if you were drinking the night before. Or if you were excessively dehydrated. Or, or, or...

[Tech Diver]

Greg, Luminary:
In the interest of preventing divers from thinking they could never get bent at certain depths, I hereby revise my statement statement from

"In conclusion, we can completely rule out DCS as a cause of Condor's physical discomfort"

to

"In conclusion, it would be extremely unlikely that DCS was a cause of Condor's physical discomfort based on this particular profile and the assumption that there was no previous Nitrogen loading in the tissues or that any medication/chemicals were inhibiting the exchange of gases."

[condor13090]

On the Bermuda dive we just went straight up from 35 ft. after being down for 45 mins. and never stopped at 15ft. for 3-5 mins. I just think thats wrong and being irresponsible. This guy owns a diving operation so why would he have me do this. Is it possible that people from Britian just do things differently? I would think PADI and SSI would follow the same techniques no matter what part of the world your in.

[luminary]

Originally posted by condor13090
On the Bermuda dive we just went straight up from 35 ft. after being down for 45 mins. and never stopped at 15ft. for 3-5 mins. I just think thats wrong and being irresponsible. This guy owns a diving operation so why would he have me do this. Is it possible that people from Britian just do things differently? I would think PADI and SSI would follow the same techniques no matter what part of the world your in.

I don't think this is a matter of where the person was from or what certifying agency they were a part of. I think they were just being irresponsible. Remember, the doctor who finished last in his class could be yours . Not every dive op owner or instructor should be an owner or instructor. I think you just got unlucky.

[gregt]

Tech Diver,

I agree completely that the odds are almost nil. It's just important to also be aware of the limitations of software models.

Good discussion!

[Tech Diver]

Originally posted by gregt
...It's just important to also be aware of the limitations of software models...

Agreed. It should be understood by everyone that decompression modeling is merely an approximation for an extremely complicated system of interactions that take place at the molecular biology level. If you ever use decompression software you should be fully trained in technical diving. Although not a technical diving requirement, I personally feel it is important to have a very strong understanding of decompression theory to improve safety by knowing when to override the recommendations of the software. Even then, things sometimes happen that nobody can explain because this science is still not completely understood. This is also the reason why dive computers should not be followed blindly when approaching decompression limits because they mostly use the same algorithms and tables.

[drgabe]

Tech Diver... doesn't your model assume someone who is in good physical and medical health? Does it take into account those with vascular disease (diabetes, heart issues, venous disease)? I was under the understanding that people with these issues have impaired nitrogen gas release, thus increased risk of DCS over the general diving population.

[condor13090]

Good thread! I did drink at least 4-5 glasses of wine the night before...I know thats not good...it's probaly why I got sick as this happened once before many years ago on an ocean fishing trip in Oregon with 8 ft. swells, plus another guy who drank the night before also got sick. On the plus side the fish really started hitting and we caught 60 snappers in an hour...3 at a time! Some good chum...
Another factor could be the new wet suit...I had on a 1/2 mil skin and a 5 mil wet suit that was never worn before and over heating may have worsen the situation. What might be real comfortable at depth may overheat you struggling at the surface. Plus I felt so constricted with the suit and once I was winded I removed the snorkel and still couldn't catch my breath. It felt like a Boa constricter was choking me...

[Tech Diver]

Originally posted by drgabe
Tech Diver... doesn't your model assume someone who is in good physical and medical health? Does it take into account those with vascular disease (diabetes, heart issues, venous disease)? I was under the understanding that people with these issues have impaired nitrogen gas release, thus increased risk of DCS over the general diving population.

Yes, the software assumes that the diver is "normally" vasculated. Remember, this software is used for planning technical dives. Someone who has a vascular disease is definitely not considered qualified to be a technical diver, because the diminished capillaries definitely reduce the efficiency of gas exchange between the blood cells and the lungs. Furthermore, a person with a vascular disease should not partake in recreational diving either, because all dive tables and dive computers also assume a "normally" functioning circulatory system. As you correctly stated, there is an increased risk of DCS over the general diving population.

I presume that you noticed a statement that Condor made about taking heart medication. Although I do not know the details of the reason for this, I have been assuming that it is not for any sort of vascular disease. All candidates enrolling in SCUBA training who are on any prescription medication are required to get a physician's approval for taking the class. I can not imagine any qualified physician giving a patient with such a disease the approval to go ahead. Thus my assumption.

[Tech Diver]

Originally posted by condor13090
...I did drink at least 4-5 glasses of wine the night before...

Concor, I don't want to seem overly righteous here, but I must ask why you would go diving the next day after having that much alcohol? All open water training materials state clearly and repeatedly that alcohol and diving DO NOT MIX, and having "at least 4-5 glasses" is a pretty substantial amount. Please don't take this posting the wrong way; I am just concerned for your safety.

[condor13090]

Well that was the day before the dive so I wasn't drinking and diving, But I did feel a little off the next day.
As for the heart disease I did have a double bypass 2 years ago and that does concern me a little. I don't mind diving to 60 ft. but a friend wants me to do some wreck diving in the ST. Lawrence to 120 ft. and I'm not willing to push my limits so I'll pass.
As for my doctor allowing me to dive...the type of surgery I had does not limit me in any way. I'm in better shape than most 20 year olds and do alot of mountain climbing, hiking and biking for being 48.
I really appreciate all the positive comments...Thanks George

[drgabe]

Originally posted by Tech Diver
All candidates enrolling in SCUBA training who are on any prescription medication are required to get a physician's approval for taking the class. I can not imagine any qualified physician giving a patient with such a disease the approval to go ahead. Thus my assumption. [/B]

You'd be surprised. Most of my colleges dont have any idea what goes on during the physiology of diving. For one, they'd listen to the enthusiasm behind Condor's voice and give the ok, not knowing the true risks associated with such activity.

My assisstant for my open water dive had insulin dependent diabetes, congestive heart failure, and coronary heart disease, though he was very well controlled on medication. Still he dove as often as he could, though he could barely carry his rig to the boat/shore.

Dont presume that all physicians have a working knowledge of diving physiology. (As a side point we have a small chapter in physiology texts called "Diving Physiology" and it doesn't come close to covering recreational diving).

Condor, if you have had revascularization surgery in the past, I am going to presume due to a chronic disease please correct me if I am wrong, then you will have impaired gas exchange, peroid. Its great that you are in superb health otherwise, but I'd have to think long and hard before putting my signature on a release for diving on someone with new vascularture.

[luminary]

Originally posted by condor13090
Well that was the day before the dive so I wasn't drinking and diving, But I did feel a little off the next day.

Not to sound nit picky, but that is drinking and diving. The actual intoxication will have well worn off, but it's unlikely that you will be fully rehydrated, especially for a morning dive. When I dive, I keep my drinking to no more than 1 soft liquor the day before (1 beer or 1 glass of wine, absolutely no hard liquor). Of course, everyones physiology is different. You just need to remember that there is more to worry about from alcohol than just intoxication.

Originally posted by condor13090
As for the heart disease I did have a double bypass 2 years ago and that does concern me a little. I don't mind diving to 60 ft. but a friend wants me to do some wreck diving in the ST. Lawrence to 120 ft. and I'm not willing to push my limits so I'll pass.
As for my doctor allowing me to dive...the type of surgery I had does not limit me in any way. I'm in better shape than most 20 year olds and do alot of mountain climbing, hiking and biking for being 48.
I really appreciate all the positive comments...Thanks George

I would strongly recommend you pass on a 120ft dive at this time. Especially on a wreck in the St. Lawrence (I'm sure there are some easy ones, but most I've heard of are intermediate or advanced dives). Not because of your heart condition though...IMO you need to get a bunch more 60ft and under dives in with no issues before attempting a deeper water dive. There's no rush, let yourself gain some experience. Once you log 10, 20, 30, whatever dives in the sub 60ft range without incident then you can start slowly increasing your depths. Maybe try a 75 a couple times...then 90. Take it incrementally and see how your body reacts.

[condor13090]

Thats exactly how I feel...one step at a time. As a hang glider pilot of 27 years I know what the risks are and if it doesn't feel right we have a saying...live to fly another day! Another is; there are old pilots and there are bold pilots...but there are no old bold pilots.
Also airplane pilots cannot fly for 48 hours after having just one or more drinks because it takes that long to be sharp again...
Mental conditions should also be taken into consideration too...like just having a fight with the girlfriend or troubles at work...they all put another risk factor into anything we do.