Nitrox for older divers

[TMHeimer]

I was always under the impression that age is a factor because of poorer circulation-- so ongassing and offgassing isn't as good as I used to be. Could be wrong, and presume it's another DCS factor that science is still unsure of.

 

[Ukmc]

Not according to DAN statistics,
The overall per-capita DCS claims rate (DCR) was 20.5 per 10,000 member-years. Based on the age-adjusted DCR, males submitted 28% more claims than females. Male-to-female difference was greatest between 35 and 40 years of age and disappeared by the mid-50s. Highest rates were observed in the 30- to 39-year age category, after which DCR declined with increasing age. Highest yearly DCR was estimated in 2002. Insurance dropout rate was greater among those who had DCS in the first year of their insurance compared to those who did not have DCS in their first year.
According to this the older you are the least chance you are of getting DCS older divers are wiser divers. The 30 to 39 year olds should start using nitrox on air tables

Dear Mac, your above argument may be correct, as some variables are independent and some may not be. Your example of potentially increased risky behavior (especially for males) at the younger age has been brought up at this board before and is likely true. It is also possible that 30-39 year olds have collected a lot of experience (or may think they have) and diving more aggressive profiles and may put themselves at higher risk.
The way I think about NitrOx is as someone is giving you a head start in the race, except the total is your nitrogen load. If you are Usain Bolt , you don’t need a head start, but most of us mortals could use it (some more than others)
Other than MOD I don’t see a disadvantage of NitrOx.
Now if you want to argue cost effectiveness, or as we call it number of patients needed to treat (how many divers need to use NitrOx to save on from getting bent) then it is a different argument and we can probably do some calculations for that

 

[Celt]

Dear Mac, your above argument may be correct, as some variables are independent and some may not be. Your example of potentially increased risky behavior (especially for males) at the younger age has been brought up at this board before and is likely true. It is also possible that 30-39 year olds have collected a lot of experience (or may think they have) and diving more aggressive profiles and may put themselves at higher risk.
The way I think about NitrOx is as someone is giving you a head start in the race, except the total is your nitrogen load. If you are Usain Bolt , you don’t need a head start, but most of us mortals could use it (some more than others)
Other than MOD I don’t see a disadvantage of NitrOx.
Now if you want to argue cost effectiveness, or as we call it number of patients needed to treat (how many divers need to use NitrOx to save on from getting bent) then it is a different argument and we can probably do some calculations for that

Older divers already dive more conservative than younger ones and to suggest that they dive nitrox using air tables is a mistake in my opinion. But at the end of the day if it makes someone feel better happy days. I use O2 to shorten my time hanging under my boat but stick to the tables and dive plan.

 

[Celt]

The way I think about it, an older diver has more scar tissue from lumps and bumps along the way. Wholly apart from the risk of silent cardiovascular disease in an otherwise healthy 60+ year old, I think about scar tissue and its poor perfusion compared with other tissues (like muscle) as being more reluctant to give up nitrogen due to its poorer blood supply. That type of tissue is more likely to bubble after acquiring a nitrogen load. And the scarring may not be just in muscle or joints. Think of silent mini strokes or silent heart attacks that you never even knew you had. Those tissues won't easily give up nitrogen either, and they're not in benign places.
That's my rationalization for using nitrox all the time as an older diving physician/former hyperbaric doc.

I believe that was the answer I’m looking for but why couldn’t a 40 year old who has lived a sedentary life style have the same problems. I don’t have a problem with individuals choosing to dive conservatively but I worry when I hear blanket advice been given to a certain age group.

 

[Ukmc]

Older divers already dive more conservative than younger ones and to suggest that they dive nitrox using air tables is a mistake in my opinion. But at the end of the day if it makes someone feel better happy days. I use O2 to shorten my time hanging under my boat but stick to the tables and dive plan.

I agree with you entirely. Lying to your own computer or to yourself by diving air table while using NitrOx in my mind constitutes lack of self control. It is like people who chronically late who will set their watches 15 minutes forward... I prefer to lay out a conservative profile and dive appropriately to the plan. I also agree with you that some 40 year olds are in a lot worse shape than other 70-80 year olds, but I suspect, a lot of those have sedentary lifestyle and probably are not divers. If they are divers and have many DCS risk factors they should be factoring it in...

 

[MaxBottomtime]

The rate of DCS events has decreased less than one per cent since nitrox became widely available. Setting your computer to air while diving nitrox doesn't increase your safety any more than driving 63 in a 65 zone. I prefer to know exactly what gas I'm diving and what my ndl is at any point in the dive. I'm not going to fudge and guess that I must be OK.

 

[TMHeimer]

I agree with the last two posts. I don't even set my watch ahead 2-3 minutes (so I won't be late for something) anymore. I set it to the TV, which is always correct....

 

[caydiver]

I like Nitrox and use it unless it is over the limit. Since I started volunteering at the local chamber it has become more important to me. I am only an attendant/driver but am there when the dive docs give their input. With multiple days or older divers they often seemed dismayed when a few bucks seem too much to stop someone from using Nitrox.

 

[ls1dreams]

IMO nitrox is a no-brainer for nearly everyone. Why not reduce DCS risk?

I'm convinced that the vast majority of divers have taken some kind of mild DCS hit and not realized it.

 

[MaxBottomtime]

Since nitrox came into general use, DCS cases have declined less than one-tenth of a percent. There is only a minuscule reduction of risk. Nitrox does give me more ndl, which is the only reason I use it.