Teenager with DCS, mother in denial, treatment delayed

[Celt]

LOL. He keeps changing what he is saying. Good luck pinning him down!

Don't tell me you looked in your crystal ball again and saw what I was thinking.

 

[kaylee_ann]

This is a very real thing and specifically what made me switch to helium in my breathing gases below 100 feet.
Many years ago, I was doing a dive in Lake Erie on a wreck at 160'. This is a dive I had done 10 times before. I was using air just as I had always done in the past. On this dive, while swimming down the hogging arches, my vision narrowed and I got extremely uncomfortable, I have never figured out what caused it on this dive, but my solution was to abandon my dive partner and high tail it back to the down line, go up and start deco. My partner caught up to me at 20' with a WTF look. On the boat we were discussing what happened and I had no answer to why I bailed and left him for dead.
On that dive, I had driven 6 hours, paid a charter, bought two nights in the most expensive dump of a hotel known to man and then didn't enjoy myself because I decided to save $40 on breathing gas.
That was my last dive on air below 120.
It wasn't a new site, it wasn't a new boat, it wasn't a different gas, it was just a different day.

that's freaky how you can just go in to such a different/impaired state of mind with no warning. it just happens, and before you know it, you're reacting too quickly to stop. that can be really dangerous- I'm glad you're okay!

 

[PirateFoxy]

Problem is, muscle weighs more than fat so someone that’s in very good shape could weigh more than someone who’s, well, not.

Yeah, there’s much better metrics for assessing fitness than weight, especially if you’re talking about a population that may tend towards being more athletic (muscular) anyway. Plus spending a lot of time in the water changes fat distribution so even someone who does have a few extra pounds may not be carrying them in places where it makes a big fitness difference. (AIUI you basically tend to have more subcutaneous fat - it’s why many Olympic swimmers, in spite of being in insanely good shape, have a softer muscular look than other athletes of similar fitness levels. More fat stored under the skin for insulation instead of in other places.)

Depending what aspect of fitness you’re interested in exactly, waist-hip ratio can be good - it’s more predictive than BMI for cardiovascular issues.

 

[boulderjohn]

Depending what aspect of fitness you’re interested in exactly, waist-hip ratio can be good - it’s more predictive than BMI for cardiovascular issues.

Quite a few years ago, Dive Alert magazine published DAN studies on dive fatalities that correlated fatalities with fitness as measured by the BMI. I wrote a letter challenging the use of the BMI for that, and I actually got a phone call in response, with an editor saying they had just encountered some sources supporting my position and wondering about my participation in a follow up article. I declined because I have no credentials in that field.

So they got an MD to do the follow up article, and he wrote an article compared methods of measuring personal fitness. It said the BMI is the very worst for measuring individual fitness because, as people noted earlier in this thread. It starts with a very, very thin and not very strong ideal weight and height ratio and then assumes every pound over that very thin, weak ideal comes from fat. The BMI is really only useful for comparing large populations, where individual differences can even out.

About the time of that article, I was at a weight and fitness level I wish I could attain today. The BMI had me as seriously overweight. I did a hydrostatic body fat test (the gold standard for that), and it had me in excellent condition for my age. That test also had a chart identifying what my body fat index would be if I lost weight by losing only fat. According to that chart, if I dropped to 0% body fat, I would still have been overweight according to the BMI. The only way I could get out of the overweight category on the BMI would have been to lose muscle mass.

 

[PirateFoxy]

Quite a few years ago, Dive Alert magazine published DAN studies on dive fatalities that correlated fatalities with fitness as measured by the BMI. I wrote a letter challenging the use of the BMI for that, and I actually got a phone call in response, with an editor saying they had just encountered some sources supporting my position and wondering about my participation in a follow up article. I declined because I have no credentials in that field.

So they got an MD to do the follow up article, and he wrote an article compared methods of measuring personal fitness. It said the BMI is the very worst for measuring individual fitness because, as people noted earlier in this thread. It starts with a very, very thin and not very strong ideal weight and height ratio and then assumes every pound over that very thin, weak ideal comes from fat. The BMI is really only useful for comparing large populations, where individual differences can even out.

About the time of that article, I was at a weight and fitness level I wish I could attain today. The BMI had me as seriously overweight. I did a hydrostatic body fat test (the gold standard for that), and it had me in excellent condition for my age. That test also had a chart identifying what my body fat index would be if I lost weight by losing only fat. According to that chart, if I dropped to 0% body fat, I would still have been overweight according to the BMI. The only way I could get out of the overweight category on the BMI would have been to lose muscle mass.

Exactly. I am definitely actually overweight at the moment due to exercise difficulties from arthritis, but even before my arthritis flared up and I gained weight, I was always “overweight” per BMI because I’m naturally quite muscular. Between that and the boob fairy being overly generous, I’d have to be quite unhealthy to get down to where the BMI charts say I should be. We are supposed to have *some* bodyfat.

If I’m remembering right, waist-to-hip ratio just measured with a tape measure is better because it’s measuring where your fat is stored - abdominal fat is correlated with more cardiovascular health problems. (It’s been a while since I read about it.) Thought it is still a very simplified metric and obviously a proper medical evaluation with appropriate testing and blood work is most appropriate if people want to really know what is going on for fitness assessment purposes to plan dives or any other significant physical activities. Especially if we’re talking about things that might influence circulation and heart health, like cardiovascular disease, as it is entirely possible to be quite slim and still have things like partial blockages that become a Major Problem when you start needing more blood flow than usual.

 

[ginti]

Plus spending a lot of time in the water changes fat distribution so even someone who does have a few extra pounds may not be carrying them in places where it makes a big fitness difference. (AIUI you basically tend to have more subcutaneous fat - it’s why many Olympic swimmers, in spite of being in insanely good shape, have a softer muscular look than other athletes of similar fitness levels. More fat stored under the skin for insulation instead of in other places.)

I wasn't aware of this phenomenon; does it have a name? could you explain a bit more, especially how and why it happens? Do you have any references for that?

Thanks a lot

 

[PirateFoxy]

I wasn't aware of this phenomenon; does it have a name? could you explain a bit more, especially how and why it happens? Do you have any references for that?

Thanks a lot

I read about it a while ago related to one of the summer Olympics, I’ll see if I can turn it up again.

 

[Dr Simon Mitchell]

Oh, it works alright and in all the case I am personally familiar with, not hard to prove it does.

Sorry, I have been travelling and missed this, so coming in late. A number of themes have emerged in this thread that deserve a comment.

1. Efficacy of in water recompression. This has been a controversial topic for decades, but the diving medicine community finally appears to be coming to an evidence-based consensus on it. There is now good evidence that very early recompression (which is the one advantage of doing it in water) is effective, and that administered early, a short, low-pressure recompression on oxygen (not air) is usually effective. The evidence alluded to is detailed here, and the international consensus on the place of IWR in DCS first aid is available here.

2. Who you should call and what should happen when DCS is suspected after a dive. The answer to this question is context sensitive.

If there is clearly a life threatening emergency (eg unconscious diver) then immediate EMS contact is critical.

With a sick but non-critical diver, I would always recommend involving someone with diving medicine knowledge (e.g. DAN) in the discussion early. Considerable experience tells me that left to their own designs, EMS will sometimes get this wrong as will ER staff with no specific training in diving medicine (and no one gets any at medical school!). For example, a paralysed diver taken to a hospital with no recompression facility, or a well-looking diver with stable vital signs in an ER gets triaged to a non-urgent pathway where no-one does an early neurological examination and thus progressive leg weakness is missed.

In addition, in relation to a comment by @formernuke depending on the symptoms and circumstances, it is not unusual (or wrong) for a diver with seemingly mild symptoms to be directed to somewhere local simply to facilitate a competent neurological examination. This allows informed decisions to be made about what to do next, particularly if accessing recompression is going to logisitically difficult or even hazardous. This approach is codified in a Figure from a recent review article [1]:

Finally, @Kay Dee I'm sorry, I remember the IWR kit, but I don't have a photo of it!

Simon M

Reference:
1. Mitchell SJ, Bennett MH, Moon RE. Decompression sickness and arterial gas embolism. New Eng J Med. 2022;386:1254-64.

 

[formernuke]

@Dr Simon Mitchell

Was is good that I sat at the ER for 8 hrs with absolutely nothing waiting for said neuro exam?

That was what got me if I had gotten the bends that delay could have had very bad consequences.

 

[John the Pom]

This is a very real thing and specifically what made me switch to helium in my breathing gases below 100 feet.
Many years ago, I was doing a dive in Lake Erie on a wreck at 160'. This is a dive I had done 10 times before. I was using air just as I had always done in the past. On this dive, while swimming down the hogging arches, my vision narrowed and I got extremely uncomfortable, I have never figured out what caused it on this dive, but my solution was to abandon my dive partner and high tail it back to the down line, go up and start deco. My partner caught up to me at 20' with a WTF look. On the boat we were discussing what happened and I had no answer to why I bailed and left him for dead.
On that dive, I had driven 6 hours, paid a charter, bought two nights in the most expensive dump of a hotel known to man and then didn't enjoy myself because I decided to save $40 on breathing gas.
That was my last dive on air below 120.
It wasn't a new site, it wasn't a new boat, it wasn't a different gas, it was just a different day.

There is a big difference between 100' (30 metres) and 160' (nearly 50 metres). I have only experienced / seen very mild narcosis at 30 m, while I have seen an experienced diver unable to function safely at 50 m on air (e.g. on a twin tank / twin regulator set-up, trying to swap regulators to balance his air consumption but kept putting the same regulator back in his mouth. and couldn't understand why one SPG was reading low while the other one wasn't changing. He was fine by the time we took him back to the first deco stop, BTW.)