sleepy, scuba makes me very sleepy, zzz

[Northeastwrecks]

kelpmermaid once bubbled...
I am Nitrox certified and don't get to use it much, but when I have, I personally have not noticed a real difference. Northeastwrecks, could the after-effects of an adrenaline burn also have contributed to your fatigue after the rescue?

Your point is well taken, Adrenaline burn have contributed, but I don't think that it was a significant factor.

I'm familiar with the feeling of adrenaline burn letdown. That usually produces a relaxed feeling of relief and usually passes within an hour or so after the event. After the rescue, I felt total exhaustion that presented a couple of hours after I left the boat.

In addition, the circumstances of the dive suggest a bordeline profile. A new buddies' regulator failed at approx. 71 fsw (turns out she didn't have the tank valve on all the way). She panicked after accepting my primary and tried to bolt, so I went behind her, dumped her BC and started a controlled ascent. At about 40 fsw, I stopped for what was supposed to be a 1 minute hang (which was supposed to be followed by stops at 30, 20 and 10). Her boyfriend panicked when I stopped and hauled us both to the surface. We swam the conscious and apologetic diver to the boat, put her on O2 and called it a day.

As mentioned, I was so exhausted that I thought about getting a room. In hindsight, I should have.

 

[divemistress]

but i should have noted: this also takes place when i teach scuba in confined water, in a pool less than 15' deep! i can't figure that one out. except perhaps the usual: lack of sleep, cold, tension, inadequate hydration, etc.

as far as vacations, i do dive nitrox whenever possible, but i can and probably should:
* slow ascents
* increase frequency and duration of safety stops
* haul bottled water onto dive boats to drink. (the water and punch most operators supply is NASTY.)
* dress warmly. i do get cold very easily.

then again, i think hallmac and a few others have a point: this is vacation! i've probably stayed up most of the night pre-flight to get ready, not to mention working late hours for a couple of weeks.....sleeping is something my body needs, whether i dive or not.

that indeed is true. i've never had to pull the car over and take a nap post-dive. but i sometimes have to do it after work, at the end of the day.

thanks, y'all, i'll test this on my next trip.

 

[The Pirate]

divemistress once bubbled...
i'm not fatigued, not tired, but sleepy. after a few dives, all i want to do nap. (so i'm not a heck of a lot of fun on dive trips )
does anyone else feel this way?

Take it for what its worth, but you are experiencing a form of sub-clinical DCS. It is the result of excess nitrogen in your system. Try slowing your ascent, add some additional stops before you get to 20', and stay at 20' for at least 10% of your bottom time. If you really want it (the sleepiness), to go away, add helium to your gas to reduce the nitrogen, but only after you have received proper training in the use of helium based diving mixes, like the GUE recreational triox course. Good luck and sweet dreams.

 

[divemistress]

quote from me:
divemistress once bubbled...
i'm not fatigued, not tired, but sleepy. after a few dives, all i want to do nap. (so i'm not a heck of a lot of fun on dive trips )
does anyone else feel this way?



and from reefraff:
"Bent" doesn't necessarily mean hospitalized. Even if classified as mild or "sub-clinical" DCI, the short and long-term impact of micro-nucleated bubbles on your body is not good.


****************************************************
btw, what's "geezer gas"? nitrox?

 

[Drew Sailbum]

WARNING:I am no doctor, do take this with a big ol' chuck of salt.

Lots of things are happening physiologically throughout a dive and the period following the dive. We all know about nitrogen uptake and something about its elimination. I suspect that some cases of mild sleepiness may be related to to a physiological rebound of sorts that follows a dive.

(Side note: Nitrogen dissolves in fat tissues readily. Nerves are insulated inside a sheath of a type of fat. Muck up the insulation, and transmission of nerve signals can be effected.)

Our bodies experience a cooling in most every dive, and one of our primary responses is to constrict the blood vessels in our extremities and skin. Your body then experiences a neurologically mediated response to keep your blood pressure from rising excessively. Momentarily, your heart may slow and normally we all quickly adjust.

At the end of the dive, we go from the weightless environment of a neutrally buoyant dive back to the harsh gravity of the surface. The heart must now force blood up into the head against the force of gravity. The normal response is to comparitively constrict blood vessels in the lower body (as compared to those in the head) and another adjustment of heart rate. All mediated by nerves.

Here's my conjecture. Residual nitrogen may complicate an already delicate balance. There are known medical conditions in which this balance is affected resulting in alteration of heart rate and/or blood pressure resulting in fatigue or even loss of conciousness. I guess that the added strains associated with diving may cause some people to experience enough of a heart rate slowing to experience sleepiness.

That's the only physiological process I can think of, but the doctors around here may have a better idea.

 

[Irishdiver]

This thread is starting to worry me

I don't think the sleepiness I referred to earlier is sub-clinical DCS, though I'm open to the possibility. I know that it's possible to suffer DCS even when diving within all the rules and regulations.

My understanding of cold dives is that:
1. Allied to the vaso-constriction some of you referred to in earlier posts, extra nitrogen loading is incurred (because nitrogen becomes more soluble as the temperature decreases).
2. On return to the surface - at the correct ascent rate - the increased penalty kicks in because [apart altogether from the normal out-gasing process] the temperature has risen and therefore the nitrogen loses the additional solubility.
3. Due to the 'oxygen shunt', the excess nitrogen that has been taken on board takes longer than might otherwise have been expected to out-gas, leading to poor gas exchange and a relative oxygen deficit.

Although the cold dives I referred to are not 'working dives', the temperature is around 2C, so the effect of the cold on the body is quite extreme. As a result, we always make these dives very conservative and dive them to the Buehlmann (sp?) tables, factoring in the increased penalty for a cold or working dive as recommended.

I might add that the sleepiness I refer to occurs not after the first dive but only after a repeat dive. All my dives in this quarry have been in a 7mm semi-dry, so I have been climbing back into a wet, wet suit and feeling pretty chilled even before beginning the second dive.

In addition to this, the access to the quarry is up and down a pretty sheer 40 ft drop without steps (we have to use a rope to haul ourselves back up) and the access to the lakes involves a 250-metre hike in full gear with weights. Obviously, this physical exertion is not an ideal scenario and will probably add significantly to the DCS risk.

Observations?

 

[DocVikingo]

Yes, I have an observation.

Performing activities such as a 250-metre hike in full gear with weights to access the dive site, and then hauling oneself up a sheer 40' wall after each dive, often a very cold water dive, is rather ill-advised.

This sort of strenuous physical exertion involving the joints is well-known to increase the presence of tiny gas bubbles, also called micronuclei or seed bubbles, in blood & tissues. This free gas-phase of nitrogen is the proximal causative agent in DCS & is to be minimized at all costs.

Any ideas you could come with to reduce such a vigouous courting of micronuclei formation would be in your best interests.

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.

Best regards.

DocVikingo

 

[DocVikingo]

RE: "Guys like me have long used geezer gas for years because we feel better after diving on it. Some will tell you that the benefit comes from the increased oxygen intake, but the clinical evidence indicates that it comes from the reduction in nitrogen."

Could be please direct me to sources of a scientific nature demostrating that a reduction in N2 makes one feel better after diving?

Thanks.

DocVikingo

 

[The Pirate]

One other thing you should consider is severe hypoglycemia. If you as most people on dive trips eat some sugary snack before the first dive of the day, then do your dive, you probably come up sugar depleted. If you, like most americans then eat a standard breakfast or whatever with a lot of simple carbs, you could spike your sugar level which then drops rapidly an hour or so later, rendering you very sleepy. I call it a hypoglycemic coma. That coupled with sub-clinical DCS would render you completely useless.

 

[DocVikingo]

Calling it a "hypoglycemic coma" is inaccurate as this is a medical term referring to loss of consciousness secondary to significantly low blood glucose level.

Hypoglycemic fatigue would be a better term. BTW, this can occur at levels less than "severe hypoglycemia."

Best regards.

DocVikingo