Instructors and DCS

[Otter]

As an instructor, I am constantly ascending / descending during training dives shuttling students to and from the surface to the bottom, accompanying students during CESAs and AAS ascents, and the like. Thankfully, most of these are occuring in 20-30 fsw of water so presumably, I am not loading up on Nitrogen.

Are the risks significantly greater for me in these situations and what, if anything, can I do to help mitigate any risk.

TIA

Otter

 

[Dr Deco]

Otter:

Because the deep is so shallow, the nitrogen uptake is small, as you mentioned. There is therefore little to be feared from joint-pain DCS (the bends).

The biggest hazard in this range is the rapid change of pressure with small change in depth and a resulting problem with Boyle’s law. This is the much feared pulmonary barotrauma.

One can only mention the prime directive of ”keep your airway open.”

Dr Deco :doctor:

Readers, please note the next class in Decompression Physiology :grad:
http://wrigley.usc.edu/hyperbaric/advdeco.htm

 

[Otter]

Certainly that is my prime concern for both my students and I.


I took a look at the class outline, looks interesting. How early does it usually fill up?

Otter

 

[Dr Deco]

Otter:

The decompression physiology class usually has a few places until the last week. This year, however, I have already received several inquiries, and so it looks to be a "hotter topic" this year.

MRP:doctor:

 

[Drew Sailbum]

Though the nitrogen load may be minimal, it shouldn't be ignored. A former instructor at our shop got bent on a 21ft dive. Diagnosed and treated by the doc at the chamber.

In an average month in Grand Cayman, approximately 5 divers are treated for DCS in the chamber at Georgetown Hospital. Of those, usually one or two are dive instructors.

The rate of DCS for dive professionals is alarmingly high enough that DAN has been recruiting dive pro participants to participate in the ongoing Project Dive Exploration. The DAN intern was at our shop today getting the various computer functions working properly so a few of our staff can start sending in data.

 

[vicky]

As Dr Deco said, speaking of shallow dives Nitrogen uptake is small. However, you should keep in mind that your tissues may contain dissolved Nitrogen from your previous dives. In this case, try to avoid too fast ascents or at least be aware that you are in higher DCS risk (I think that most instructors are in higher risk).
If you want to lower the risk, then plan your day so you have at least an hour or two after making deep dives (you can use this time for theory classes), don't do CESA or rescue exercises after deep and/or long dives, etc. I don't know what organization you're working with, and if you have the liberty to re-organize your day scheduling during courses in order to make them safer for you. Do you do other dives during courses such as intros and/or guided dives?

Also, you must mitigate as many "DCS risk factors" as possible- drink a lot of water, rest (!), try to consume less alcohol (especially if your planning deep dives the next day), and so on.

 

[Diver0001]

Otter once bubbled...
As an instructor, I am constantly ascending / descending during training dives shuttling students to and from the surface to the bottom, accompanying students during CESAs and AAS ascents, and the like. Thankfully, most of these are occuring in 20-30 fsw of water so presumably, I am not loading up on Nitrogen.

Are the risks significantly greater for me in these situations and what, if anything, can I do to help mitigate any risk.

TIA

Otter

If I believe what I read then the risks are somewhat higher, which is only logical.

There are a few things you can try:

- try to limit the number of ascents required during training by letting your c.a. (or c.a.'s) shuttle students back and forth when feasible. This will cut out a few ascents by spreading them across two divers.

- always train CESA's and/or AAS ascents on the first dive of the day and make sure you're clean to start with (24 hours dry).

- Use nitrox. For shallow training dives you can use EAN36 or higher and reduce your risk somewhat. I know the PADI party-line is that this isn't scientifically proven to work but I would suggest that it would be if someone would just look into it.

- Make sure you're well rested, well hydrated and not on any medication, hung over etc etc when you're going to make a lot of ascents.

- Wear good exposure protection

Someone else will probably add to the list but these things popped to mind.

R..

 

[Otter]

for all of the suggestions.

I think in my (our) situation, we are less likely to get a hit than in many other locations. Generally, our open water dives are shore-based and occur on Sat & Sun. So nitrogen loading from previous dives is pretty rare, given the infrequent intra-week diving and we only do 2 dives per day (Laguna Beach requirements during the summer prevent classess after 10:00 am). Also, its unusual for us to do ocean dives for an O/W class on the same day as an AOW or Speciality.

Thanks again

Otter