hot tubs and diving (liveaboard question)

[farsidefan1]

Excellent information here. What a great site! RJP, you crack me up, thanks bud. Yes, I will be traveling solo this trip, as I often do and I hate to inconvenience others. I think RJPs advice is excellent. I just have to get over it and ask for help. I have the shirts and some under stuff that is supposed to be helpfull which I will wear under the wet shirt. I also purchased a hood which goes under the wet shirt which would avoid the hooded vest smothering problem (yeah, I know, a silly worry).

As to my original question (assuming the thing works) how about if I hot tubbed BEFORE diving? would that be a problem? Thanks again, Jay

 

[DocVikingo]

Hi Jay,

Interestingly, pre-dive exposure to high temperature may have a protective effect against DCS, but many parameters remain to be determined.

Here is my Jul '09 Undercurrent (Scuba Diving Magazine, Undercurrent Reviews Dive Resorts, Liveaboards, & Diving Gear) piece on a recent study of the matter:

"Can Saunas Prevent Decompression Sickness?

By adhering to conservative profiles like slow ascents, extended safety stops and appropriate surface intervals, the healthy, fit diver faces only minuscule risk of decompression sickness (DCS). Still, much has yet to be proven about the exact causes of DCS. According to a recent study, a long sit in a hot sauna may help to prevent it.

In their article published in the journal Aviation, Space and Environmental Medicine, researchers from France had 16 military divers take a 30-minute dry sauna heated to 49 degrees Fahrenheit. An hour later, the divers took a simulated dive to 98 feet in a hyperbaric chamber. Then, everyone did the same dive without sitting in the sauna beforehand. Post dive Doppler readings found that circulating bubbles were reduced by about a third in divers who had done the sauna/dive procedure. They also had significant reductions in systolic blood and pulse pressures.

Researchers opine that the decrease in inert gas bubbling may in turn decrease the risk of DCS. Possible reasons include changes in plasma heat shock protein and nitric oxide levels, and sweat dehydration. However, the findings can only be considered suggestive for the time being.

Even if these findings are replicable, various temperature levels will need to be tried to see if lower temperatures can produce similar results. There’s really no safe, workable way to subject the body to temperatures in the 150-degree range other than by dry sauna (wet environments at that level could cause burns). If the reported reduction in gas bubbling in fact does require temperatures at or near this extreme, you’d be out of luck if you don’t have access to a sauna heated to this temperature range.

As a final caution, it’s important not to confuse pre-dive with post-dive sauna, or even with post-dive hot tub, shower or other methods exposing the body to high temperatures. Excessive heat after a dive can accelerate inert gas elimination and increase bubble formation, and so should be avoided. Besides deep stops and slow ascents, spending your first hour of post-dive time in a warm, but not hot (or chilling) setting, is another way to keep DCS at bay. - - Doc Vikingo

“Predive Sauna and Venous Gas Bubbles Upon Decompression from 400 kPa,” by Jean-Eric Blatteau, M.D. et al.; Aviation, Space and Environmental Medicine, December 2008."

Regards,

DocVikingo

This is educational only and does not constitute or imply a doctor-patient relationship. It is not medical advice to you or any other individual and should not be construed as such. Consult with your physician.

 

[farsidefan1]

Thanks DocVikengo, I was hoping you would respond. Excellent. I will not get in a hot water situation till the next morning pre diving. That works for me. I will also follow the other extra conservative protocals (nitros using air tables, slow ascents with stops halfway up (unless current is taking me to PNG) and long (12.5 minute) safety stop at 15-20 feet. Also I will make sure my surface intervals are over an hour and closer to 2. I am still debating limiting myself to 3 dives plus a couple night dives. That is, going to be very tough. Probably will go to 4 a day.
Thanks again, Jay

 

[Doubler]

Define Hot tub. I look at that as water temperatures in the 100's. Hot tubs on the Aggressors are more like Luke Warm Tubs, doesn't quite have the same advertising appeal. The water sloushes out during travel so the tub isn't turned on to maintain heat, then if you want to use it, cold water is added to bring up the tub level. The hot shower on the dive deck is warmer. Advise don't worry about it and get a 3 mil.

 

[farsidefan1]

Luke warm is actually ok with me. I was just thinking it would be nice to take the mid week chill out of my body. I really do hate wearing full wetsuits. My soulder surgery involved a rotator torn in 3 places, a compresion injury, some arthritus and a bone spur. Makes wetsuits more than inconvenient. They are downright painfull. I have avoided them this long, Probably won't start now. The shirts I'm ok with. The additional hood, ok, maybe. I got a shorty but I'll have to get pretty chilled to use it.

 

[DocVikingo]

Define Hot tub. I look at that as water temperatures in the 100's. Hot tubs on the Aggressors are more like Luke Warm Tubs, doesn't quite have the same advertising appeal. The water sloushes out during travel so the tub isn't turned on to maintain heat, then if you want to use it, cold water is added to bring up the tub level. The hot shower on the dive deck is warmer. Advise don't worry about it and get a 3 mil.

Excellent points.

Regards,

DocVikingo

 

[Dr Deco]

Hello Readers :

Hot Tubs

That has not been much – any actually - laboratory research on the topic of hot tubs and DCS. There is not any funding for “recreational activities” when cancer and stroke loom as much bigger threats. That is easy to understand. None the less, I would expect to hear reports of divers with problems if there was a hazard from this activity, since divers have been using hot tubs for decades. Instead, what we get are queries as to safety.

Individuals are quick to point out that nitrogen solubility is reduced in a liquid as the temperature increases. While true, the solubility is changed a very small amount within the temperature ranges for human comfort.

Movie Script

Is it possible for a problem to arise? If asked, I could write this for a book or a movie script. Let us say for purposes of the plot, it is desired that a character have a terrible mishap following a scuba dive. This is not at all far fetched.

The diver undertakes several dives wherein the nitrogen gas loading is large. I must add that the diver is somewhat on the heavy side, that is, carrying considerable abdominal fat. This is loaded with nitrogen because of the nitrogen solubility in adipose [fat] tissue.

The diver goes into a hot tub following the dives and stays, let us say, for a half hour. The diver then exits the tub by pulling himself up while at the same time, holds his breath [as people often do when exerting themselves] and then releases it. This is essentially a Valsalva maneuver. Copious gas bubbles from the belly fat pass through the PFO and flow to the brain. The bad news is that he is experiencing a bubble load situation with a volume of several cubic centimeters. The bubbles initially pass through the brain capillaries, but the volume is too much. Soon, the vessels become occluded.

The diver slumps over, and expires, and a mystery is afoot.

Dr Deco :doctor:

 

[boulderjohn]

Since this is a 2 week trip I purchased a shirt with hood (I read about a guy who nearly sufforcated trying one on in dive shop so I'm a little apprehensive about it since I had major shoulder surgery a yr ago).

Was I the guy who nearly suffocated?

If so, that report was about 95% in pure jest. I was laughing my head off at my incapacity as it happened, and the guy who eventually peeled me out of it was laughing harder. I tried to get a laugh by publishing a mock accident report on it, and I succeeded. One time I taught a class and during the course of it made a reference to the experience, at which point one of my new students said "You're Boulderjohn!" She had run into my description on some humor web site somewhere.

It was a hooded vest that was seriously too small for me. I still have it, by the way. I have never warn it since that incident. If you are smaller than I am and are interested, I can give you a screaming deal. (Hopefully without too much screaming.)

But seriously folks, I always wear plenty of thermal protection when I dive. I am pretty cold tolerant so it doesn't take much, but even in warm Caribbean waters I wear a 3 mm full suit. I always wear full suits, too, because you never know when some stray jelly tentacle will nip you.

 

[Pegger]

Could hot tubs affect a persons blood pressure that might make it unsafe for diving?

Regards

 

[farsidefan1]

Rotflmao, thanks John, it may well have been your report I had flopping around in the back of my head. If it was too small for you there is little hope for me:fruit:I was mostly kidding too. My gripe with the exposure suit is with the shoulder I'm not great at reaching back and I truly hate coming off as a semi invalid that needs help getting dressed. I will be traveling solo so..., Yeah, I just need to get over it. I have a couple wet shirts and even have a 3 mil. Course I have never used the 3 mil