freediving and DCS

[mania]

This is not my story. It happend to a friend of mine. Please don't mind the translation (I'm not very good in medical terms in Polish - so in English it's even worse). I would like to know your opinion what was the reason of DCS. Is it possible that the freediving???? This the translation of his story:

I was in Egypt for a week. From the beginning I was planning 5 days of diving, Saturday and Sunday as lazy days. But diving was so great that I decided to get one more day – Saturday. I was supposed to fly back on Sunday night (precisely 1 am Monday). Everyday we had 2 dives, not deeper than 35m (I was deeper that 30m probably two times). Every time we did the safety stop. On Friday after 2 dives I went only with ABC to have a nice swim. I saw a dolphin so I dived from 2 meters to 10 -15 and one free dive down to 20m. The return swim to the boat was rather tiring. Next day – Saturday I did 2 dives – 11:30 am for 28m (total time 48 minutes) and the second one at 13:30pm, depth 28m, 53 minutes with a really long safety stop. Unfortunately on Saturday, after the first dive we found out that our flight was rescheduled to Sunday at 14:45. So it was precisely 24 hours after the last dive. Our plane had two intermediate landings. Anyway Saturday was a beautiful day, so I even stayed on the deck on the sun. I don’t remember how much water I drunk. I do remember that on Friday night I had two alcohol drinks but I wasn’t drunk, or anything close to it. My computer showed the end of “no fly time” 40 minutes before taking off. So I seemed safe. On the airplane I could feel pins and needles in my arm, so I was even joking that it’s DCS, but it passed so I didn’t pay much attention to it. I landed in Warsaw at 9:20pm on Sunday. During the night I felt some pain but I thought it was of fatigue. On Monday morning and during the day (till 3pm) everything was ok. Around 3pm I started feeling pins and needles in my right leg and arm. It was a horrible traffic so I was driving home an hour and a half. Later I called decompression chamber (it’s in Gdynia – Northern Poland) and they told me to contact the nearest hospital. I did it and I was checked by neurologist. At the same time the hospital contacted the decompression chamber and finally at midnight I flew there by a small medical plane ( we were flying at the height of 3000 meters). The flight took an hour. During the flight I was breathing the oxygen (10- 15 liters of oxygen per minute). Around 1:40 am I was in the decompression chamber. At 2am I was inside it and the plan of decompression was based on V US NAVY tables. I was supposed to stay there for 2 hours and 9 minutes. Me and the doctor were compressed at the 12 meters and I was breathing pure oxygen for 20 minutes. The regulator was working really hard and I felt like almost suffocating. So we had 5 minutes of break, again compression as for 18 meters and oxygen. Slowly the pins and needles were passing. After 15 minutes I got convulsions – the brain toxicity of the oxygen. The normal thing are gaps in the memory. I don’t remember how I left the chamber (unfortunately I remember vomiting in it) and how I got to the room and how I bite my tongue to the blood. On Tuesday morning I woke up with a drip but I didn’t come back to the chamber. After a whole day of observation I was let back home.

 

[Saturation]

This is not my story. It happend to a friend of mine. Please don't mind the translation (I'm not very good in medical terms in Polish - so in English it's even worse). I would like to know your opinion what was the reason of DCS. Is it possible that the freediving???? This the translation of his story:

I was in Egypt for a week. From the beginning I was planning 5 days of diving, Saturday and Sunday as lazy days. But diving was so great that I decided to get one more day – Saturday. I was supposed to fly back on Sunday night (precisely 1 am Monday). Everyday we had 2 dives, not deeper than 35m (I was deeper that 30m probably two times). Every time we did the safety stop. On Friday after 2 dives I went only with ABC to have a nice swim. I saw a dolphin so I dived from 2 meters to 10 -15 and one free dive down to 20m. The return swim to the boat was rather tiring. Next day – Saturday I did 2 dives – 11:30 am for 28m (total time 48 minutes) and the second one at 13:30pm, depth 28m, 53 minutes with a really long safety stop. Unfortunately on Saturday, after the first dive we found out that our flight was rescheduled to Sunday at 14:45. So it was precisely 24 hours after the last dive. Our plane had two intermediate landings. Anyway Saturday was a beautiful day, so I even stayed on the deck on the sun. I don’t remember how much water I drunk. I do remember that on Friday night I had two alcohol drinks but I wasn’t drunk, or anything close to it. My computer showed the end of “no fly time” 40 minutes before taking off. So I seemed safe. On the airplane I could feel pins and needles in my arm, so I was even joking that it’s DCS, but it passed so I didn’t pay much attention to it. I landed in Warsaw at 9:20pm on Sunday. During the night I felt some pain but I thought it was of fatigue. On Monday morning and during the day (till 3pm) everything was ok. Around 3pm I started feeling pins and needles in my right leg and arm. It was a horrible traffic so I was driving home an hour and a half. Later I called decompression chamber (it’s in Gdynia – Northern Poland) and they told me to contact the nearest hospital. I did it and I was checked by neurologist. At the same time the hospital contacted the decompression chamber and finally at midnight I flew there by a small medical plane ( we were flying at the height of 3000 meters). The flight took an hour. During the flight I was breathing the oxygen (10- 15 liters of oxygen per minute). Around 1:40 am I was in the decompression chamber. At 2am I was inside it and the plan of decompression was based on V US NAVY tables. I was supposed to stay there for 2 hours and 9 minutes. Me and the doctor were compressed at the 12 meters and I was breathing pure oxygen for 20 minutes. The regulator was working really hard and I felt like almost suffocating. So we had 5 minutes of break, again compression as for 18 meters and oxygen. Slowly the pins and needles were passing. After 15 minutes I got convulsions – the brain toxicity of the oxygen. The normal thing are gaps in the memory. I don’t remember how I left the chamber (unfortunately I remember vomiting in it) and how I got to the room and how I bite my tongue to the blood. On Tuesday morning I woke up with a drip but I didn’t come back to the chamber. After a whole day of observation I was let back home.

Its likely diver created too many micronuclei as a result of all the post dive activity, and freediving after diving is high risk for getting a DCS 2 hit. Whatever small and insignificant bubbles may be compressed by diving and enter into the arterial circulation. Vigorous swimming with freediving after diving could form bubbles in the spinal cord. The rapid ascents with freediving will tend to make small bubbles grow. Once in the brain or spinal cord, the bubble could have been too small to be off issue, but the change in barometric pressure made them grow enough to cause problems. If the bubbles cause bleeding or intermittently press against structures, it could explain the off-on symptoms. That diver received likely a USN TT5, a very mild recompression, and had good results suggest the bubbles were small, but were alas, in a troubling spot.

 

[Dr Deco]

Hello mania:

It seem to be what Saturation has indicated, namely, you friend had neurological DCS. Considerable activity on the surface will generate those tissue nuclei/microbubbles and cause trouble.
It is always best to avoid considerable strenuous activity. :sprite10:

Unfortunately, divers concentrate on dive tables and gas loading and then pay little attention to microbubble generation. looking at meters and table, one can see that they are more similar than different. This is probably the reason why we have not seen a difference between meters in terms of risk of DCS. To my knowledge, the risk is roughly independent of the brand of decompression meter.

Dr Deco :doctor:

 

[jplacson]

What's the story of freediving and DCS? I mean, are freedivers prone to DCS as well? How come they can ascend much faster (basically as fast as they want)

And how long AFTER a SCUBA dive must you wait before freediving? Is 12 hours enough after a normal dive?

I'm thinking of taking up freediving and doing a freedive on Sundays, after my Saturday scuba dives.

 

[sharkmasterbc]

jplacson - The reason freedivers do not get DCS is because they are not breathing compressed air. There is of course still nitrogen and other gasses being disolved into their tissues but not even close to the amount we have while on scuba.

 

[jplacson]

So even though guys like Pipen can stay down at 50' or so for quite a while... NO2 loading isn't significant enough that you can basically shoot up and not have any microbubble formation?

Freediving has always been interesting to me... watching them dive to depths of 30'-50' and stay for a minute or two... just finnning... no tank... no bubbles... no bulk. Almost like being on an RB, except $10000 cheaper!

 

[holdingmybreath]

Freediving has always been interesting to me... watching them dive to depths of 30'-50' and stay for a minute or two... just finnning... no tank... no bubbles... no bulk. Almost like being on an RB, except $10000 cheaper!

That's it in a nutshell. It's not unusual to hear of freedivers getting DCS, especially during spearfishing tournaments or rigourous freediving (short surface intervals, repetitive deep depths) but the likelyhood of getting DCS while recreational freediving is very slim. During competitions divers ascending from the depths will generally slow down during their last 30' or so to the surface.. especially if they have taken a sled ride down and a balloon ride up. Not quite your purest form of freediving, but freediving none the less.

 

[fins wake]

That's it in a nutshell. It's not unusual to hear of freedivers getting DCS, especially during spearfishing tournaments or rigourous freediving (short surface intervals, repetitive deep depths) but the likelyhood of getting DCS while recreational freediving is very slim. During competitions divers ascending from the depths will generally slow down during their last 30' or so to the surface.. especially if they have taken a sled ride down and a balloon ride up. Not quite your purest form of freediving, but freediving none the less.

Yes. There is also some information on freedivers and DCI in Bennett&Elliott (5th ed.) and the latest Edmonds, Lowry&Pennefather. Mainly on Japanese and Korean pearl fish divers.

 

[pipedope]

can be found on the WKPP site;

http://www.wkpp.org/articles/Decompression/why_we_do_not_bounce_dive_after_diving.htm

Don't take it as the final word but don't discount it either.