Metabolic Rate or Aspirin Effects

[mccabejc]

A couple of questions:

Anyone know if there is a coorelation between a person's metabolic rate and decreased risk of DCS? My non-medical mind was conjecturing that if your metabolism is high you might tend to offgass N2 more quickly or more efficiently.

Also, could the blood thinning effects of aspirin be a benefit in N2 offgassing, similar to the way that hydration helps the process?

 

[Dive-aholic]

Both good theories, but neither tested or proven either way.

Your first premise makes sense. Look at Navy Dive Tables and current tables. Current tables a little more conservative. Navy tables were designed based on young, fit sailors...who probably had high metabolic rates.

I've seen lots of articles on the ASA effect. No proof because no one has tested it. But the general consensus I've found is that there is no harm in taking a baby ASA (81mg) each day when diving.

Did I not answer your questions adequately?

 

[tb]

A couple of questions:

Anyone know if there is a coorelation between a person's metabolic rate and decreased risk of DCS? My non-medical mind was conjecturing that if your metabolism is high you might tend to offgass N2 more quickly or more efficiently.

Also, could the blood thinning effects of aspirin be a benefit in N2 offgassing, similar to the way that hydration helps the process?

Asprin isn't a blood thinner; it reduces platlett aggregation (stickiness) which is thought to afford a degree of protection against DCI by lessening part of the reactive process set in motion during a hit. So it's not so much a contributor to off-gassing as I understand it. But yes, asprin or anything else that decreases platelett aggregation can be prudent along with adequate hydration, good cardivascular fitness and all of the other practices that constitute dive safety.

 

[Saturation]

A couple of questions:

Anyone know if there is a coorelation between a person's metabolic rate and decreased risk of DCS? My non-medical mind was conjecturing that if your metabolism is high you might tend to offgass N2 more quickly or more efficiently.

Also, could the blood thinning effects of aspirin be a benefit in N2 offgassing, similar to the way that hydration helps the process?

Its long known in decompression, higher metabolic rates cause high consumptions of 02 and increases the size of the oxygen window for decompression.

During dives per se however, higher metabolic rates equally increases the demands for gas for the same level of dives, thus they are often 'gas hogs.' A fit diver who can 'zone out' or relax completely during dives can substantially reduce gas consumption. If quiescent rates of gas consumption are high, it also suggests poor fitness or an underlying disease process that cause 'hidden' 02 consumption demands.

There are no studies to show a difference between folks of various metabolic rates on decompression.

The only known correlate to decompression effectiveness is fitness as measured from V02max.

ASA remains with unclear benefit in DCS. Worse case, it could enhance neural injury by causing mostly ischemic infarcts to become hemorrhagic, leading to higher chances for lasting disability. Most DCS injuries do contain hemorrhagic areas. Its used commonly, as with other analgesics, to relieve residual pain after recompression.

Articles such as this are a dis-service and do not quote studies that showed no benefit for these therapies. While the effects on aggregation are well known, what isn't known is whether aggregation itself is a factor in DCS.

http://www.inspired-training.com/aspirindiver.htm

There is ONE study showing a benefit of a type of NSAID during recompression.

http://www.ncbi.nlm.nih.gov/entrez/...&dopt=Abstract&list_uids=14620099&query_hl=27

Bottom Line:

If a diver is on ASA daily for general health reasons, there is no need to discontinue same to dive, since its protective use is for other diseases.

For a healthy individual to take ASA or an NSAID to enhance decompression efficiency or peri-compression outcome is not advised because BENEFITS are unknown, BUT SIDE EFFECTS are known, so benefits do not outweigh the risk for side effects in this case.

 

[miguel sanz]

completely agree with saturation. Just one more think, the asa effect on platelates is irreversible while the antiaggregation effect of other NSAID are reversible.
Although the hipotesis of mccabejc are reasonable, there are many unknown factors so that something sound logic doesn´t mean it´s right.
ASA is a great drug, saves lots of lives, but at the same time it´s one of the drugs that kils more people around the world.

 

[tb]

An ounce of prevention- in this case a baby asprin- whichI believe is generally well-tolerated. But then, so is a regular asprin for a short period as noted in the OTC literature. I personally use omega3 fatty acids to keep my platelets slippery but there are so many simple ways to do that, including a baby asprin that I can't think of a good reason not to, given the following:
<a href="http://www.vnh.org/FSHandbook/11mgmt_dcs.html">platlet aggregation in DCI</a>
< a href="http://www.emedicine.com/emerg/topic53.htm">acute treatment</a>

 

[Dr Deco]

Hello readers:

Metabolic Rate

There is a correlation between resting [basal] metabolic rate and DCS over a wide range of animal species. In humans however, the correlation does not really exist. In this case, I believe you mean, &#8220;resting metabolic rate.&#8221;

One major factor in changing &#8220;metabolic rate&#8221; is musculoskeletal exercise. Physical activity will increase it. The role in DCS will depend on the timing and intensity of exercise.

As &#8220;Saturation&#8221; mentioned, the better correlate is &#8220;maximal oxygen uptake.&#8221; This assesses physical fitness and is linked, in part, with blood flow to the tissues.

Aspirin

The experiments originally linking aspirin and DCS were performed on small animals. The end point for DCS in these studies was death. Clearly, this is not joint paint DCS as meant by recreational divers.

When aspirin was tested with human divers, there was no relationship. This is because blood coagulation does not play a role in mild DCS. Missed decompression with large nitrogen loads and a great many bubbles is a different matter, but has not been tried with human subjects &#8211; as you might guess.

Dr Deco :doctor:



References :book3:

Kindwall EP. Metabolic rate and animal size correlated with decompression sickness. Am J Physiol. 1962 Aug;203:385-8.

 

[caribou]

I guess I'm confused on what "having a high metabolic rate" means. I was told several times by different doctors that I had a high metabolic rate. I'm not an professional athlete but certainly am in very good physical shape, according to several benchmark in different sports. My resting heart beat is 45/min at rest, goes to 55-60 while diving. It is also very quick to drop back down after an intense exercise.

My doctor explains my low weight (145 lbs, 6"1) with my metabolic rate. It is true I'm rarely cold when others are cold, as if my body was regulating more, but using up more energy to do so.

Can anyone make some sense out of this ?



I'm 6"1,

 

[Dive-aholic]

Metabolic rate is the rate that your body burns calories. A basal metabolic rate is the calorie burning rate at rest. When you're told you have a high metabolic rate, it just means you burn a lot more than the average calories, which keeps you thin.