Can we infer DCI before symptoms develop?

[DevonDiver]

@DevonDiver: You seem to be advocating that all stops (deco, mandatory safety, and optional safety) are mandatory. Correct me if I'm wrong.

Not at all. I'm probably not expressing myself well. A recreational diver has optional [Adjective: Available to be chosen but not obligatory] safety stops.

What I am trying to convey is that there may be cases where a recreational diver would be imprudent not to choose to complete one. Fast ascents and other predisposing DCS factors have a direct bearing on that prudence.

After an otherwise faultless dive, with little-no DSC predisposing factors/events, then it is a simple matter of conservatism to employ a safety stop.

After a bad dive, where DCS predisposing factors/events are present, then it goes beyond mere 'conservatism' and becomes a prudent proactive measure to help prevent DCS.

I guess you could call this the 'level of urgency' that the stop possesses - which is dictated by the dive events.

I've never been a fan of the term "mandatory safety stop." I believe PADI invented that term so that it wouldn't be making reference to deco stops on the PADI/DSAT RDP.

I don't agree. It isn't deco - there is no 'ceiling' produced by the table algorithm. However, it is sufficiently close to that 'grey area' that the importance of completing a stop becomes more critical. Therefore, PADI advise divers to always plan to conduct the stop under those circumstances. However, as it is not a algorithm-produced 'formal' stop, then it can be 'blown off' if other, more critical, factors/risks present themselves.

The key word being 'plan'. You always plan a 'mandatory safety stop'. You can opt to plan other safety stops, if you like.
You can abort any safety stop, if doing so is the lesser of two evils.

A deco stop proposes that you have an unhealthy risk of DCS if you abort/miss it.
A safety stop proposes that you have a healthy chance of avoiding DCS, whatever you do.

However, in physiological terms there is no strict line between deco and no-deco.
It isn't really "safer" to miss a safety stop when you have 1 min NDL remaining, than if you blow a deco stop one minute later.

Some divers 'ride the curve' by multi-leveling on ascent, whilst maintaining 1-2 minutes of NDL on their computers. Those same divers freak at the notion of going into deco. I mean... really??!!?

What I'm trying to illustrate is that it is equally senseless to apply that same line of thought in respect to safety stops.

Put simply, there are times when a diver should treat a safety stop with the same respect that they would treat a deco stop.

 

[ianr33]

Just to add that if a diver misses a couple of minutes deco/safety stop for whatever reason the absolute worst thing to do is immediately struggle up a bouncing ladder or walk heavy gear up a hill. Do a 10 minute "surface safety stop" Enjoy the view,smell the roses.

Exertion immediately after a dive with a high N2 loading is a bad thing.

 

[RonFrank]

For the Rec diver here are some general rules to follow:

• A slow ascent is a good idea.
• A 3 minute SS (15ft) is good, 5 minutes is better.
• If your computer wants a Deco Stop oblige it. When it calls for a mandatory deco stop, it is mandatory.
• If you have a run away ascent, immediately go back down and finish the dive. If you end up at the surface for more that a minute after a run away ascent, end the dive.
• Once you are out of the water remain so.
• If you feel you are at risk for DCS stop diving for the day. Likely nothing will happen. But symptoms can develop for up to 3 hours after a dive (rarely more). If symptoms develop, seek treatment immediately and avoid air travel. If nothing develops you can always dive tomorrow.

The long discussions on DCS on this rec forum are complicated, not 100% understood, and rather pointless. DCS is very rare in rec divers. If you think you have the bends stop diving and seek medical attention.

 

[lowviz]

If a diver does something that might cause decompression illness, would it ever make sense to seek medical attention before symptoms develop?...//...

The uncertainty of "what to do" or "should I intervene" in a particular situation is how I originally read this post. Great question.

Put him on oxygen and transport to EMS. ...//....

Figured that this would be the thread-killer. Wrong.

The devil is in the details... ...//...

Isn't it though!

Keeping it in "Basic Scuba Discussions", let's say I've been at 90' for about 25 minutes then decide to head up properly -but cork. Hit the surface breathing like a freight train through my reg, take 10 seconds to self-assess while hanging onto the downline, feel fine, What next???

I posed a nasty but plausable OW/AOW scenario, nobody bit.

BT, if you miss a deco stop for less than a minute, you are to go back down to it and do your deco times at 1.5 x the original plan, for it and all stops above it....//....

Making some progress, a "benign" miss can be recovered. Note "less than a minute". OK, this type of goof-up need not panic anyone. We have a plan!

...//... Either you're pregnant or not. To determine if you ARE pregnant, wait until you're symptomatic- or - test positive. ...//...

Heading into the bigger stuff...

Just to add that if a diver misses a couple of minutes deco/safety stop for whatever reason the absolute worst thing to do is immediately struggle up a bouncing ladder or walk gear up a heavy hill. Do a 10 minute "surface safety stop" ...//....

Really good, all too rarely offered advice. Remember this, Matt. Could be the difference between getting away with niggles and aches or a much bigger hit.

For the Rec diver here are some general rules to follow:

• A slow ascent is a good idea.
• A 3 minute SS (15ft) is good, 5 minutes is better.
• If your computer wants a Deco Stop oblige it. When it calls for a mandatory deco stop, it is mandatory.
• If you have a run away ascent, immediately go back down and finish the dive. If you end up at the surface for more that a minute after a run away ascent, end the dive.
• Once you are out of the water remain so.
• If you feel you are at risk for DCS stop diving for the day. Likely nothing will happen. But symptoms can develop for up to 3 hours after a dive (rarely more). If symptoms develop, seek treatment immediately and avoid air travel. If nothing develops you can always dive tomorrow.

The long discussions on DCS on this rec forum are complicated, not 100% understood, and rather pointless. DCS is very rare in rec divers. If you think you have the bends stop diving and seek medical attention.

Now we are into it.

Regarding: "If you have a run away ascent, immediately go back down and finish the dive. If you end up at the surface for more that a minute after a run away ascent, end the dive."

I second-guessed this sort of scenario for a couple of years. Which really means that if it happened to me (again) I still wouldn't know what to do in the heat of the moment. The agencies talk all around this but fall short of giving you a "do this" procedure after the incident. Allow me just one quick reference to tech diving. "Air Decompression for Professional Sport Technical Divers" Calhoun, Christensen have the guts to spell it out on page 24, see quote below.

USN Diving Manual Rev. 6, April, 2008: "If a diver makes an uncontrolled ascent to the surface from a no-decompression dive, he or she should be observed for one hour at the surface for decompression sickness and arterial gas embolism symptoms."

Note that there is no mention of going onto oxygen. Huge controversy. O2 "masks" DCI symptoms by fixing the problem.

Question, is it better to know the problem or get a quicker fix? -don't look at me for an answer, still sorting this one out on a personal basis.

DD and BT are sparring over this technical issue, IMHO.

Terminology:
DCI is an umbrella term for both lung overexpansion injuries and DCS (the bends).


So, Matt, the answer is yes. You place the offending diver under your care for an hour and observe him/her if you choose to take responsibility. -No prob for the diver, just a surface interval. But I would also caution that the offense should make it a last dive for the day.

 

[Bubbletrubble]

Put simply, there are times when a diver should treat a safety stop with the same respect that they would treat a deco stop.

@DevonDiver: Please don't take this the wrong way, but, at least in this thread, I feel like you have taken a very simple set of concepts (safety stop, deco stop, what to do in the event of a missed safety stop) and complicated the heck out of them. I don't think a novice diver would find this approach helpful at all.

 

[DevonDiver]

@DevonDiver: Please don't take this the wrong way, but, at least in this thread, I feel like you have taken a very simple set of concepts (safety stop, deco stop, what to do in the event of a missed safety stop) and complicated the heck out of them. I don't think a novice diver would find this approach helpful at all.

Yeah, I am beginning to think that also. I did predict it was a complicated debate Whilst trying to keep my posts understandable at 'basic' level, I've probably just made it more confusing. Damn... but I do enjoy the challenge of presenting complicated information in a way that can be understood by all. Educator ego, I guess! LOL

In the most simple terms:

1) Re-descending to complete a safety stop is a personal decision on behalf of the diver concerned, it can be based upon situational factors, if the diver is experienced enough to judge them.

2) There's little statistical risk in re-descending once to complete a stop, provided the stop is then completed and the diver ascends slowly from the stop afterwards.

3) It shouldn't ever be done if DCS symptoms have already presented. First aid and immediate evacuation is the critical response in that circumstance.

4) If DCS symptoms did start to present during a safety stop, then the diver should abort and seek immediate medical attention.

5) Prevention is better than cure. Plan your dives (conservatively), dive your plan... and control your buoyancy effectively for slow ascents.