Does an air hog have more of a chance of getting the bends?

[ianr33]

Of the computers available, the Uwatec Galileo Sol takes into account heart rate and respiratory rate to compute dive times.

And the evidence that this actually works is what exactly?

 

[imindeep]

Thank you guys so much! That was the answer i was hoping for...

:banana:

 

[Scubakevdm]

The guys are right : diffusion of gas follows gradients, whether it be from tissue to blood or blood to alveoli.
The issue of being an "air hog" and DCS risk, may however be linked to overall cardio-respiratory fitness. That is to say, a less fit person will consume air relatively faster as they reach their anerobic threshold sooner for the same level of exertion. In that case, the risk of DCS may be relatively increased compared to someone with greater "physiological reserve", fitness, under the same level of workload.
Of the computers available, the Uwatec Galileo Sol takes into account heart rate and respiratory rate to compute dive times.

Gosh, I think I exert myself less diving than I do laying down in bed. I'm not sure how cardio-respiratory fitness would play into my gas consumption. I could see if I was an underwater racer how it would matter though, or diving into a high flow cave or something.

 

[dschonbrun]

ScubaKev... metabolism of Oxygen, and efficient use of energy, are key to a person's breathing rate. If you don't need much oxygen to perform, then you can breath slower and work with a lower heart rate. Great endurance athletes often have extremely low SAC's as divers.

 

[HBO MD]

I guess that depends what you do in bed.
Nevertheless, in terms of proof relating to the model used by Uwatec, it is an extrapolation of the fact that gas uptake is, in part, delivery dependant. Since delivery is a function of cardiac output, heart rate is used as a surrogate, (assuming stroke volume is constant). Therefore it is not unreasonable to modify deco profiles based on constant monitoring of this parameter which will vary in relation to work load.
Safe diving.

 

[Dr Deco]

Hello imindeep :

"Air Hog" and the Lungs

Breathing rates in adults range from 13 to 22 breaths/min. From what I read, within this range, a physician cannot diagnose a pulmonary problem simply by counting breaths.

By "air hog," I am assuming we are talking about a resting diver. In this case, rapid breathing and a high SAC probably would be an indication of nervousness. The same rapid breathing when underwater would also indicate anxiousness. The diver probably needs practice in diving to allow a better[/degree of relaxation.

If the diver were active, increased breathing would be indicative of muscle activity and the need for oxygen and carbon dioxide excretion.

In the lungs, the exchange of gases in the alveoli is very fast less than the transit time of the blood through the capillary [about second]. Nitrogen enters or exits [depending on the point in the dive], and oxygen is taken up [primarily by the hemoglobin], and carbon dioxide is expelled. Healthy lungs will match the correct blood flows to a sufficient number of alveoli.

The Tissues

Gas exchange in the tissues is not rapid. The blood flow to any given tissue is sparse in comparison to the lungs. Brain tissue has a relatively large perfusion [flow] rate, muscle is less [although elevated when exercising], and connective tissue has a quite low flow. These flows are changed depending on oxygen need [metabolism] but the flows at the tissue level have little relationship to resting breathing rate.

Additionally, virtually all of the nitrogen inhaled is excreted with exhalation. Nitrogen simply has too small a level of solubility.



Dr Deco :doctor:

 

[princessaprilia]

Actually, being an air hog will probably result in a lesser chance of being bent, at least compared to someone who breathes like a girl, since you can't stay down as long. It's nature's way of helping to keep you safe until you get a few dives under your belt.

Wow, this is one of the only times that "like a girl" was used in a positive light.

"Throws like a girl" means a bad thrower - which I am.:depressed:
"Runs like a girl" means clumsy/slow - which I am.
"Breathes like a girl" using less air -which I do.