CESA - why? I'll never run low on air!

[Cacia]

So....can you see a difference in "Best Practices" and where the "Rubber meets the Road?"

Cause lots of people are not diving close enough to the buddy to actually have it help a lot. I KNOW you guys are....most divers are not.

So...I am saying that you need to change how people are ACTUALLY DIVING before you drop CESA. All the math in the world doesn't help if you don't see that, IMV.

But, I will agree you don't need to spend much time on it, it is just a reminder not to hold your breath, that's all.

 

[lamont]

Oh also, we don't really know how often a solo diver runs out of air and dies attempting a CESA. The photographer who recently was lost at sea is a good case in point. Anything could have happened there, but that is exactly how you would expect to read about a fatal OOA/CESA...

 

[lamont]

So...I am saying that you need to change how people are ACTUALLY DIVING before you drop CESA.

No real argument from me (although I do think it should still be taught, just the emphasis is all wrong).

 

[Cacia]

okay, I can buy that.

The photog did not want to dive with others and did not want to drag cylinders around in addition to his double strobes, let's not forget that part.

 

[Rick Murchison]

1. CVA - cerebral vacular accident - or a stroke. Certainly can happen underwater. We would like to treat it as a "brain attack", but rushing to the surface would add a few nitrogen bubbles and blow out a few more pieces of brain.

Sorry 'bout confusing the acronym... However... There seems to be a great misconception on ascent rates from no stop dive profiles and bubble formation.
First, a bit of history. The 30fpm of today wasn't always the standard. For decades after the development of the Navy tables, 60fpm with no safety stop was the standard. We dove the 60/60/60 (60 feet, 60 minutes max bottom time, 60fpm ascent) tables for decades with a very low (near zero) incidence of DCS. Even the 60fpm rate of ascent was a compromise between the Navy's Scuba divers, who wanted a 100fpm standard, and Hardhat divers who wanted 25fpm. Indeed, we were taught that the tables' efficacy depended on hitting 60fpm quickly and maintaining it - otherwise you'd be ongassing during the ascent and your bottom time wouldn't really be valid any more.
During doppler studies it was discovered that sometimes, asymptomatic, systemic, venous bubbles were forming in divers who were diving profiles near the edges of the 60/60/60 tables. These bubbles were not causing DCS because they were being filtered out by the lungs and dissipated there harmlessly. From these studies come the three modifications to the Navy tables we see today - pull in the "edges" by truncating the tables by one to four pressure groups for depths over 20 feet, reduce the recommended ascent rate from 60 to 30 fpm, and add a safety stop. In the near future I think everyone will also adopt the Pyle stop.
My point is that divers who are diving today's no-stop profiles are not near the edges of the 60/60/60 tables, are not likely to form any bubbles on even the venous side, and certainly extremely unlikely to form any on the arterial side, so that absent a shunting PFO, you're highly unlikely to "add a few nitrogen bubbles" to a stroke in progress, and getting a stroke victim out of the water quidkly trumps that risk to me.

2. MI - myocardial infarction - or a heart attack - certainly exertion can exarcebate it. I don't think rushing to the surface would make a difference. ... A relaxed slow ascend without panicking would be preferred than rushing to the surface and risk adding more damage to the rest of your body. I don't think spending time in the compression chamber is preferable to being in the MI-CU at 1 ATM.

How about a relaxed fast ascent, under control (that's what a CESA is, controlled). The latest conference on first aid for heart attack victims says that once a victim goes down, the chances of getting them back decreases about ten percent for every minute that passes. In water compressions are pointless - a real joke - you need to be on deck. Now! A CESA does not "risk adding more damage to the rest of your body." That's the whole point in doing one - getting to the surface quickly and safely.

3. Massive MI with cardiac arrest under the water?? You are a dead man....

Yep. Most likely. As I've said earlier, usually the first visible symptom of a heart attack is sudden death, and a CESA won't help you.

...NO AED on the dive boat ...

More and more dive boats are getting them. I'm on a mission to get one on every boat and every corner.

In either of this case, buddy assisted slow ascent will add less burden to your brain, or your heart.

A properly done CESA begun from neutral buoyancy is a near effortless maneuver. Indeed, it requires far less effort than swimming even 15 feet horizontally and grabbing a buddy. If you're "working" at it then you need to practice. In a way it's gratifying to see the widespread great concern about bubbling that's surfacing in this thread - that means our efforts to instill caution have not been without effect. But for an emergency where you need to get to the surface, the odds are hugely in favor of a CESA over concerns about bubblng for a diver who is within the recreational no-stop envelope.
Rick

 

[dumpsterDiver]

I know one excellent DIR diver. The others are a bit of a mess, works in progress, But they have beautiful trim! ...then they do the most amazing things.

I find this comment fits the image of DIR divers that I have acquired from reading this board. I have no idea if it is really representative of the population (since I don't know any of them), but it sure seems funny to me.

 

[Thalassamania]

... First, a bit of history. The 30fpm of today wasn't always the standard. For decades after the development of the Navy tables, 60fpm with no safety stop was the standard. We dove the 60/60/60 (60 feet, 60 minutes max bottom time, 60fpm ascent) tables for decades with a very low (near zero) incidence of DCS. ...

Thanks for the reminder. I find this whole discussion a bit silly since a CESA is so easy to do and has been done with such safety for so many years. Frankly I think its another case of people being afraid of something that they do not understand because an instructor who does know any better was told by an IT who doesn't know any better that if they do that they're all gonna die.

Its the same old story, declare something unnecessarily or dangerous so you can drop it from the curriculum and get your course down to two days.

 

[fisherdvm]

Yep. Most likely. As I've said earlier, usually the first visible symptom of a heart attack is sudden death, and a CESA won't help you. More and more dive boats are getting them. I'm on a mission to get one on every boat and every corner.

Thanks to you and other very patient scubaboard members, my knowledge of diving medicine has increased exponentially over the last year.

I think what you have said about CESA and MI (heart attack) is valid only if your diveboat has an AED.

Unfortunately, at the point of a heart attack, if you did go into cardiac arrest... I think a controlled buoyant surface ascent would be best. Since it is only a fraction of a second from ventricular fibrillation to loss of consciousness. If you are unconscious at the surface, you are dead..... If you are unconscious at depth, you are dead.

I think the most important thing is to signal to your buddy first, that you are in trouble. Once you lose consciousness.... and bouyantly float to the surface, if your buddy is not aware where you are - you are dead.

But even if your buddy was aware of where you are - chest compression is impossible in the water. As a recent study pointed out, chest compression alone is better than chest compression plus rescue breath...

You are correct that the sooner helps get to a cardiac arrest patient, the better. But in this case, it is the sooner you get to defibrillation the better. I almost think, returning to a dive boat without an AED with a cardiac arrest patient is a lost cause... Hopefully, one of this day, AED's are affordable and mandated on all dive boats.

 

[Rick Murchison]

Thanks for the reminder. I find this whole discussion a bit silly since a CESA is so easy to do and has been done with such safety for so many years. Frankly I think its another case of people being afraid of something that they do not understand because an instructor who does know any better was told by an IT who doesn't know any better that if they do that they're all gonna die.

Its the same old story, declare something unnecessarily or dangerous so you can drop it from the curriculum and get your course down to two days.

This morning I was just thinking about my typical checkout weekend, where I make about two dozen "normal" ascents (monitoring student air-sharing ascents) and a dozen CESAs from 30' or so. I must admit that some days dumping some of that is attractive
Rick

 

[Rick Murchison]

...Hopefully, one of this day, AED's are affordable and mandated on all dive boats.

Affordable and available, yes. Mandated? By the market, yes. By government? No, no, no, no, no! Keep the government out of our play.
Rick