So what do we think about hydration and DCS now...?

[nimoh]

I've seen people on boat gulp water like it was air, telling me they don't want to get dehydrated. Until you've been out in the Sun and can no longer sweat or even get enough spit to moisten your lips you have not been dehydrated.
I've been doing a personal study by drinking way too much Diet Pepsi over the past two decades, including several in the hours leading up to a dive. In spite of my caffeine intake and several hundred deep air dives over the past 25 years I haven't been able to get bent. I'll let you know if I ever succeed.

If you want to get Pepsico to pay you for your study, I suggest drawing the conclusion that Diet Pepsi prevents DCS

 

[farsidefan1]

I don't have any studies to quote nor is my example apocryphal. It only involves one subject but I am intimately familiar with all the details associated with it. I had just under 200 dives at the time. I had been on a couple of live aboards doing 5 dives a day for a week at a time and never had any problems. I tried to maintain hydration by normal drinking of water. An extra bottle before and after each dive. On a trip to Coz I stayed bit out of town. I did not have a heavy dive load. 2 dives day one, 2 dives day 2 then 3 dives day 3.

Very mellow considering that on boats or at Cocoview I always got in my 5 daily dives. I never "overdid" things and never pushed the limits of my computer. The only difference of this trip *other than my unusually light dive schedule, was that day 2 after diving I walked into town for dinner. It was a long walk and it was in the August heat. I'm from Utah where high humidity is anything over 40%.

After my 3rd dive day 4 I felt quite a bit of pain and then some numbness. I called DAN and described what was happening and they gave me an address and told me to catch a cab. I was in a chamber within 20 minutes. Dr. Piccalo did an assessment (thanks to DAN he was there waiting for me) and sent me into the chamber with a guy to watch over me. Usual 6 hours followed by a day in the hospital followed by another 3 hours the next day. I checked in with him daily and after a week I was cleared to fly home.

The only thing I could see different was that I became quite dehydrated on that trip due to the long walk into and back from town in the heat. Later I was counseled to check in with a dr. to see if I had a PFO as dive doctors looking at my dive profile could see no reason for my "unprovoked attack". I did find that I had an ASD (same as a PFO but a slightly different location in the heart.

Given that I obviously had the ASD during all my previous dive trips and given that I was diving a MUCH kinder gentler profile that week I have to assume that lack of hydration was a very likely difference maker.

Just my experience but blasting away about no conclusive evidence or definitive studies won't change my mind. I think it can play a significant role! Been there done that and got the T shirt.

 

[danvolker]

I don't have any studies to quote nor is my example apocryphal. It only involves one subject but I am intimately familiar with all the details associated with it. I had just under 200 dives at the time. I had been on a couple of live aboards doing 5 dives a day for a week at a time and never had any problems. I tried to maintain hydration by normal drinking of water. An extra bottle before and after each dive. On a trip to Coz I stayed bit out of town. I did not have a heavy dive load. 2 dives day one, 2 dives day 2 then 3 dives day 3.

Very mellow considering that on boats or at Cocoview I always got in my 5 daily dives. I never "overdid" things and never pushed the limits of my computer. The only difference of this trip *other than my unusually light dive schedule, was that day 2 after diving I walked into town for dinner. It was a long walk and it was in the August heat. I'm from Utah where high humidity is anything over 40%.

After my 3rd dive day 4 I felt quite a bit of pain and then some numbness. I called DAN and described what was happening and they gave me an address and told me to catch a cab. I was in a chamber within 20 minutes. Dr. Piccalo did an assessment (thanks to DAN he was there waiting for me) and sent me into the chamber with a guy to watch over me. Usual 6 hours followed by a day in the hospital followed by another 3 hours the next day. I checked in with him daily and after a week I was cleared to fly home.

The only thing I could see different was that I became quite dehydrated on that trip due to the long walk into and back from town in the heat. Later I was counseled to check in with a dr. to see if I had a PFO as dive doctors looking at my dive profile could see no reason for my "unprovoked attack". I did find that I had an ASD (same as a PFO but a slightly different location in the heart.

Given that I obviously had the ASD during all my previous dive trips and given that I was diving a MUCH kinder gentler profile that week I have to assume that lack of hydration was a very likely difference maker.

Just my experience but blasting away about no conclusive evidence or definitive studies won't change my mind. I think it can play a significant role! Been there done that and got the T shirt.

Keep in mind that for many divers, a "long walk" before the dive could have caused muscle cramping if these walking muscles are not accustomed to this level of work load....all it would take for the DCS to occur, is muscles cramping or even just tightening up and impairing blood flow.

And--it would seem that the ASD could easily aggravate this problem all the more---without it, your lungs may have "filtered" the bubbling better, and maybe mitigated the issue ( but this aspect would need a Doc to comment on).

Good luck!

 

[Duke Dive Medicine]

Personally, I think many divers have a tendency to "over hydrate". I'm not saying this is a bad thing, more than necessary water is not a bad thing compared to too little. It's just that I see people CONSTANTLY "hydrating".

The body can use only so much water, the rest is discharged as perspiratin and urine.

My philosophy is to stay properly hydrated, that is consume the amount of water that the medecial sciences recommend for your particular age, weight, activity, etc.

Safe dives . . . . . .
. . . , safer ascents!

the K

We are in the process of demonstrating that overhydration can indeed be detrimental in individuals susceptible to immersion pulmonary edema.

There is little evidence to show that dehydration is a risk factor for DCS, even though it makes intuitive sense. DCS can cause dehydration via the inflammatory process so if a diver comes to us bent and dehydrated, it can turn into a chicken-egg thing. Dehydration often gets blamed for unanticipated/undeserved DCS hits but as another poster has observed, hydration level is subjective and is difficult to measure in the field so we take that with a grain of salt.

I will add to Dan's observation about sports drinks. These drinks are designed for exercising athletes who are burning a great deal of available glucose stores, not divers sitting around sweating in wetsuits. The high sugar content of some of these beverages can actually contribute to dehydration in some cases. We recommend that divers stay adequately hydrated; plain old water is sufficient in most cases. Sugar-containing sports drinks should be balanced with an equal volume of water.

Best regards,
DDM