Does more loaded nitrogen equal higher risk of DCS?

[Scuba J7]

So now what, you want to pick a specific tissue compartment? The question was simply does more N2 increase the risk of DCS.

You should go troll the guy wants to be an instructor the cheapest and fastest way he can.

I meant compare separate specific compartments....this is why I just shouldn't do this.

 

[redacted]

I guess I should apologize. Perhaps my guestions go beyond the level of knowledge and understanding that an instructor should be able to convey to an OW student. Maybe it is sufficient if the student simply learns that more N2 = more DCS risk. They should be able to learn the mechanics of pressure groups without really understanding what they are

 

[Lorenzoid]

I think that this is really semantics rather than decompression physiology. Risk is the product of the likelihood of something bad happening and how bad it is, right? And since it's hard to quantify the second number, it's always relative.

I'm not a commercial diver, but from what I understand the chance of them getting DCS is pretty low because their decompression is managed by professionals using elaborate and expensive specialized equipment like surface supplied gas and an on-board decompression chamber. On the other hand, the deco diver's decompression is managed by the diver himself using the few tanks of compressed gas that he can carry with him. So I'll bet that the DCS rate is a lot higher in recreational divers than in commercial sat divers.

Which is more risky, flying in a commercial aircraft or riding your bike in city traffic? Well, it depends on how you define risk. You are a lot more likely to crash on your bike, but that's a lot more survivable than a plane crash.

I agree. We can call it "semantics," but the original question seems so broadly worded as to invite questions about what "risk" means. What does "higher nitrogen load" mean? As some have replied, it requires consideration of the concept of tissue compartments. What does "higher risk" mean in the context of the original question? I think it leaves the same sort of room for discussion. I think it's reasonable--though perhaps more semantics than physiology--to argue that no matter how highly one's tissue compartments are loaded, "risk" to the diver's health depends in part on managing the nitrogen load, i.e., decompressing.

 

[Duke Dive Medicine]

We did some probabilistic modeling comparisons with different dive profiles and decompression algorithms a while back:

[abstract]DECOMPRESSION RISK EVALUATION FOR TRIMIX DIVES DERIVED FROM COMMERCIALLY AVAILABLE DESKTOP DECOMPRESSION ALGORITHMS

The poster itself isn't uploaded to Rubicon but the gist is that according to the Navy's probabilistic modeling software, the probability of decompression sickness (pDCS) increased with increasing depth and bottom time with each of the decompression algorithms we used.

The caveat is that these were simulated trimix dives and the probabilistic model that was used was designed for HeO2 dives. The numerical probability of DCS is probably inaccurate, but the upward slope of the pDCS curve is noteworthy.

Best regards,
DDM