Bringing an unconscious Rebreather diver up from depth

MHD · 13th May 2007, 11:34

Quote: (Originally Posted by Gilles)

I agree on the first point, but with a BOV fitted, there are no diagnostics to get wrong. My airway was managed by my self by the bailout mix and volume I made.

It is your call, but I cant agree that a BOV + strap protects your airway. Even if you are breathing you can be sucking in water around your lips. And that can be fatal. FFM will offer that protection. The truth is that most cases to date is that the person was unable to breath either on the loop or on OC to date once they went unconscious, so telling buddies to keep me in the water after the event to me means they have every chance of getting it wrong and drowning me.

Matt

bendomatic · 13th May 2007, 12:22

it's not antagonism, it's being politely direct. i'm tired, it's my bed-time and i get hte impression you want a one stop answer that i can't give you. i agree that a BOV is a good thing it's just not a panacea for everything. i haven't read any more of your post cos i just have to go to bed.
rachel

Digger · 13th May 2007, 12:56

I rekcon the BOV is what is going to help things not get to the point where I am unconscious. Plus I would rather a rescuer bailed me out on that and maintained a decent grip to protect the airway (when I did my rescue training it was from behind and you used a pistol grip around the mouth and tilted back the head to eusure a clear airway, holding the casualties unit/tank etc between your legs. It was very effective, my instructor told me to try and spit my reg when I doubted its effectiveness in protecting an airway, and I couldn't. I physically couldn't get the thing out of my mouth, and could do little other than relax and breathe. The same thing I have done in the past to divers who are at or beyond the point of blind panic, to keep myself safe from their flailing arms and the ability to cause damage and further incident)

Obviously the hope is that they come round on the way up once you've turned the knob, and if they're still breathing I suppose it's possible if they haven't spat the DSV. But we all know that in 90+% of cases it's going to be off to the surface, hand over to the surface team and hope they don't get bent bad enough to kill them. Then get back down and sort yourself out where possible. If you won't risk going for it and getting back down you've probably not been in the situation of rescuing an unconscious person, it's something that I can't imagine many would have the self control to do. You know the risks, and you will still do it. If anyone has managed to let someone go knowing they can't go any further then I have a great deal of respect for being so in control of the situation, and I imagine they think about the decision they made all the time, especially if it didn't turn out well.

Digs.

Gilles · 13th May 2007, 13:34

Quote: (Originally Posted by MHD)

It is your call, but I cant agree that a BOV + strap protects your airway. Even if you are breathing you can be sucking in water around your lips. And that can be fatal. FFM will offer that protection. The truth is that most cases to date is that the person was unable to breath either on the loop or on OC to date once they went unconscious, so telling buddies to keep me in the water after the event to me means they have every chance of getting it wrong and drowning me.

Matt

That is an argument I can use. I will research further.

Based on my acquaintance with fluid dynamics (Petroleum Engineer)...if relaxed lips are not sealing the mouthpeice, there remains a much higher mobility for loop/BOV gas over water due to viscosity. You also have the surface tension of the air/water interface that can act as a barrier against water flowing into a relaxed jaw obstructed by a well secured mouthpeice. However as you imply, very little liquid is needed to harm the airway.

Quote: (Originally Posted by bendomatic)

it's not antagonism, it's being politely direct. i'm tired, it's my bed-time and i get hte impression you want a one stop answer that i can't give you. i agree that a BOV is a good thing it's just not a panacea for everything. i haven't read any more of your post cos i just have to go to bed.
rachel

Politely direct welcomed. Slightly short-tempered as well

, but tempered from another good day of diving

.

**fireman** · 13th May 2007, 15:06

I think Mike is an interesting character--good point though.
Short of an ER doc/nurse at a busy large city hospital, I know I have done CPR more than everybody. If you haven't broken a few people ribs in the back of an ambulance, you haven't lived.
Anyway--
If you don't have up to date CPR training, do it. For your family friends buddies etc.
As the risk of your activities increases, So should the amount and level of emergency planning and equipement. On the EMS side if you are close to the EMS system, CPR, O2 and a cell phone might suffice. As one gets more remote an AED, airway adjuncts, Backboard. Truely remote cardiac drugs/ advanced training.
I don't have the exact numbers in front of me, but I'm sure its on the web. So from my recollection--
Stopped breathing to cardiac arrest--5 min
4-6 min after cardiac arrest, brain starts dieing, this brain damage is irreversable.
CPR will slow this down but you really need defibrillation and cardiac drugs.
If the water is cold and the patient is young, onset of brain damage will be longer.
So if a person is not breathing you don't have much time. If someone is seizing mouthpiece in-- could be a completely different story. Although people comming out of grand mal seizures are disoriented and frequently combative.
Now that I think about it, Mike you are right, a clear flow chart, based on research and professional judgement is required.
We need one for untrained OC buddies, all the way up to risky professional protocols.
Let me start with an easy example--OC buddy, rec no deco, unconscious diver--turn BOV if available, surface asap--assess patient go into CPR mode. Training required--OC buddy must be familiar with Rebreather and BOV, diver rescue techniques, and CPR. And have a way to call for help.
Thats a lot and its the "lay up"
For the more complicated events, how hard is it to take a pulse of a diver with cold water gear for example. Is it worth trying. Perhaps in an overhead or extreme deco environment...

By the way, never panic--because if your life is not on the line, there is nothing to panic about, and if it is, and you do--you will die.

Tom Rose · 13th May 2007, 18:56

Quote: (Originally Posted by fireman)

By the way, never panic--because if your life is not on the line, there is nothing to panic about, and if it is, and you do--you will die.

New instructions from the red cross...are keep the blood pumping is more important than the mouth to mouth..guess it has to do with moving oxygenated blood to the brain....of course in our cases...there is usually oxygen so we have both...but start with keeping the circulation going.

Oh yeah, those ribs are damned fragile....but the alternative is really bad...
Voice of experience from a rib cracker...

Tom

Simon Mitchell · 14th May 2007, 01:52

Hello,

Another good thread about a controversial topic.

I have made my views on this known in the past, but in short, I agree with virtually everything Matty and Rachael have said. I suppose I should preface my further comments (because I also agree with Dr Mike's sentiments) that I manage airways for a living (I am an anesthesiologist), and that I am also a consultant diving physician and an experienced CCR diver. I have been involved in management of the aftermath of more than 20 episodes of unconsciousness underwater, and like a number of others here, have seen a few in the water for myself.

Let's be clear about this (and it has already been said): there is NO single solution to this conundrum that will fit all scenarios, and priorities might conceivably shift under some circumstances. But as a general rule it is my strong belief that an unconscious diver needs to be removed from the water as soon as possible, and that this goal should take precedence over all other considerations in the vast majority of circumstances.

This view is predicated on the certain knowledge that airways are difficult enough to manage and protect in the highly ordered and dry!! operating theatre environment let alone underwater in highly stressful chaotic circumstances. In this regard, Gilles, I agree with Matty that you are placing too much faith in your BOV / mouthpiece retainer system. To be fair I dive with exactly the same configuration as you (BOV with a Drager mouthpiece retaining strap), and I agree that they do seem effective (especially when you are conscious!). But my expectation of this arrangement is that it might give my buddy more time to notice my problem and effect a rescue before I drown, but not that it will allow him or her to keep me underwater in an unconscious state so that I can complete my deco, or ascend slowly etc. Another relevant issue that has not really been highlighted is that a dry airway is only half the battle. It would be no use to have a dry airway if you are not ventilating your lungs, and unconscious subject will not ventilate unless their airway is held open. It would be very hard to do this and assess the efficacy of your intervention underwater if the diver was breathing on a loop. I do admit that with a BOV the exhaust bubbles would be visible, but maintaining an open (and dry) airway would still be hard for any period of time.

It follows from the above that, in general, I am against complicated algorithms that advocate analysis of the situation at depth, or trying to maintain a dry open airway for extended periods underwater. The instinctive response to an unconscious buddy should be to ask "what is the best way to get this diver out of the water as quickly as possible?". I am sympathetic to the view that if a rebreather diver has retained their mouthpiece and there remains a possibility they are breathing, then an aggressive pure oxygen purge of the loop can do no harm immediately prior to or during the taking / sending of the diver rapidly to the surface. The choice of "taking" or "sending" depends on an integration of the rescuer's perceptions of their own risk and the likelihood of an effective rescue at the surface if the victim is unaccompanied.

I do admit that there may be some circumstances where an attempt to manage the airway underwater might be justified, such as an emergency in which there is no prospect of the diver reaching adequate surface support and it is too unsafe for the buddy to accompany the victim to the surface to manage the situation themselves. Unfortunately, such scenarios are likely to have a fatal outcome no matter what options are taken.

Simon M

**fireman** · 14th May 2007, 02:14

Quote:

Unfortunately, such scenarios are likely to have a fatal outcome no matter what options are taken.

Thanks for contributing, have some green. Yeah sometimes the hardest thing is to let go. I have seen situations where we (firefighters) line up like Lemmings to try to save one of our own. Usually cooler heads prevail. And I would do it again.
It has been said men go into battle not for god or country, but for the men standing next to us.
I still assert that preplaning that is correlated to the risk of the dive is mandatory.
Stay safe everybody.

db8us · 15th May 2007, 17:34

Quote: (Originally Posted by decoweenie)

Is this comment helpful when people are seriously trying to learn here ?

And the intended insinuation that all Rebreather divers are solo divers is way off base and not freaking appreciated!

No Phi, it is because nobody mentioned this obvious fact.
I think we just need to be aware that we can only execute this option if we are NOT diving solo with breathers.

Regards
Michael (and i will not show you my butt :-) )

Tom Mount · 15th May 2007, 17:46

Quote: (Originally Posted by MHD)

Simple review of 3 real cases

1 JasonM, showed problems at approx 110m early in dive, ascended by self to approx 30m, was escorted by another diver during ascent, went unconscious at 30m and was blown by buddy (who himself had significant deco obligation) to surface and recovered by boat crew. Was resus'd by crew and transfered to hospital. Showed signs of severe DCS hit among other symptoms. Has since made an almost full recovery. (Jason may say what his residual issues are I know he had some sometime back but no clue to there real extent, but involved a spinal hit I think)

Key item here was that diver had significant DCS obligation, but made basically a straight ascent from 100 in the end. The cause for his problem is immaterial to the subsequent management of the deteriorating and finally unconscious divers, but the key was once on surface was recovered by boat crew almost instantly and air way safety and breathing re-established. But the key thing was that once he went unconscious his time in water where he could drown was minimal. Unconscious diver under water = future drowning victim

Bent divers can be treated, dead divers can't be

Case 2

Myron Wyntonik

Grand mal seizure at 42m early in dive, lost loop, teeth clenched so unable to put reg in mouth. Was bought by divers straight to surface and back of boat where resus was commenced. Was resuscitated but had recursive drowning, and was choppered out and resus'd by para's on several more occasions.

Was released from hospital and walking and basically physically fine the next day. Key element was that while air way was unprotected, total time was probably about 90 second with either loop out or breathing water. Again time is everything with an unconscious diver. Drowning is your worst enemy. Myron had no DCS symptoms, was chambered as a precaution for a AGE. Total time on bottom was less than 5 minutes so this is not unexpected

Case 3 Rob Cook

Grand mal seizure at 3m at end of dive, no deco obligation, Was in process of bailing out , but hadn't managed to get reg in by time of seizure, so breathed water, was instantly taken on board a boat and resus'd (ie brought to surface unconscious and not breathing). Choppered to hospital and released the next day.

All 3 are successful cases where the air way was compromised. In at least 2 cases there was nothing you could have done to restore gas quality to loop, for varous reason I wont explain (it may of made no difference in the third either).

The key is the longer the time underwater the unconscious diver spends the more likely they are to die. Very simple.

These successful cases all have one thing in common. They got to the surface ASAP (all well less than 90 seconds from point of unconsciousness), and got subsequent help that meant they lived. Screwing around trying to solve other non important issues is the same is finding interesting ways to kill them.

If you take 3 minutes to get diver with a unprotected air way to the surface (ie reg out) it is all over in practice.

If you take 3 minutes to get a non breathing diver to the surface it is all over

If you can not guarantee the diver is breathing, get them to surface, who cares what their loop is or there Deco obligation. The loop it is the most likely reason they went unconscious, so get them to the surface and breathing air ASAP. Every second you screw around it is more likely they will die. DCS can kill but drowning is faster. DCS can be treated post event, death is a little more hard to rectify. Drowning is the biggest risk at this point, manage that and you will have a hope.

There are several stories floating around about people trying this and that underwater with a unconscious Rebreather divers, and they all result with the death of the Diver, the successful cases all have one common factor, minimum time with the air way compromised.

There will always be the odd exception. but for me having known 2 of the above people and being full informed of the events (case 2 and 3), this the ultimate application of the K.I.S.S principal.

Matthew

Matt great job- As I had stated long ago in this discussion getting to the surface is the key element-
DO NOT try to keep diver on loop = a drowning is eaisrer to treat than keeping a person breathing a hypoxic- hyperoxic, or hypercapnia mix

13th May 2007, 11:34	#51 (permalink)
MHD Custom Title Allowed! Current Rebreather/s: Home Build Other Rebreather/s: Sport Kiss Home Build Join Date: Feb 2005 Location: Brisbane, QLD, Australia Posts: 239	Re: Bringing an unconscious Rebreather diver up from depth Quote: (Originally Posted by Gilles) I agree on the first point, but with a BOV fitted, there are no diagnostics to get wrong. My airway was managed by my self by the bailout mix and volume I made. It is your call, but I cant agree that a BOV + strap protects your airway. Even if you are breathing you can be sucking in water around your lips. And that can be fatal. FFM will offer that protection. The truth is that most cases to date is that the person was unable to breath either on the loop or on OC to date once they went unconscious, so telling buddies to keep me in the water after the event to me means they have every chance of getting it wrong and drowning me. Matt Last edited by MHD : 13th May 2007 at 12:02. Reason: poor typing
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13th May 2007, 12:22	#52 (permalink)
bendomatic Morgan's Mum Current Rebreather/s: Sport Kiss Other Rebreather/s: Join Date: Apr 2005 Location: Brisbane Australia Posts: 205	Re: Bringing an unconscious Rebreather diver up from depth it's not antagonism, it's being politely direct. i'm tired, it's my bed-time and i get hte impression you want a one stop answer that i can't give you. i agree that a BOV is a good thing it's just not a panacea for everything. i haven't read any more of your post cos i just have to go to bed. rachel __________________ why deal with idiots on the net when you have to spend all day dealing with them at work.
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13th May 2007, 12:56	#53 (permalink)
Digger Custom Title Allowed! Current Rebreather/s: Inspiration Classic Other Rebreather/s: Not Bought Yet Inspiration Classic Classic Kiss Join Date: Feb 2005 Location: Midlands UK Posts: 196	Re: Bringing an unconscious Rebreather diver up from depth I rekcon the BOV is what is going to help things not get to the point where I am unconscious. Plus I would rather a rescuer bailed me out on that and maintained a decent grip to protect the airway (when I did my rescue training it was from behind and you used a pistol grip around the mouth and tilted back the head to eusure a clear airway, holding the casualties unit/tank etc between your legs. It was very effective, my instructor told me to try and spit my reg when I doubted its effectiveness in protecting an airway, and I couldn't. I physically couldn't get the thing out of my mouth, and could do little other than relax and breathe. The same thing I have done in the past to divers who are at or beyond the point of blind panic, to keep myself safe from their flailing arms and the ability to cause damage and further incident) Obviously the hope is that they come round on the way up once you've turned the knob, and if they're still breathing I suppose it's possible if they haven't spat the DSV. But we all know that in 90+% of cases it's going to be off to the surface, hand over to the surface team and hope they don't get bent bad enough to kill them. Then get back down and sort yourself out where possible. If you won't risk going for it and getting back down you've probably not been in the situation of rescuing an unconscious person, it's something that I can't imagine many would have the self control to do. You know the risks, and you will still do it. If anyone has managed to let someone go knowing they can't go any further then I have a great deal of respect for being so in control of the situation, and I imagine they think about the decision they made all the time, especially if it didn't turn out well. Digs.
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13th May 2007, 13:34	#54 (permalink)
Gilles Worship the feminine Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Sep 2005 Location: Den Haag (Netherlands) Posts: 762	Re: Bringing an unconscious Rebreather diver up from depth Quote: (Originally Posted by MHD) It is your call, but I cant agree that a BOV + strap protects your airway. Even if you are breathing you can be sucking in water around your lips. And that can be fatal. FFM will offer that protection. The truth is that most cases to date is that the person was unable to breath either on the loop or on OC to date once they went unconscious, so telling buddies to keep me in the water after the event to me means they have every chance of getting it wrong and drowning me. Matt That is an argument I can use. I will research further. Based on my acquaintance with fluid dynamics (Petroleum Engineer)...if relaxed lips are not sealing the mouthpeice, there remains a much higher mobility for loop/BOV gas over water due to viscosity. You also have the surface tension of the air/water interface that can act as a barrier against water flowing into a relaxed jaw obstructed by a well secured mouthpeice. However as you imply, very little liquid is needed to harm the airway. Quote: (Originally Posted by bendomatic) it's not antagonism, it's being politely direct. i'm tired, it's my bed-time and i get hte impression you want a one stop answer that i can't give you. i agree that a BOV is a good thing it's just not a panacea for everything. i haven't read any more of your post cos i just have to go to bed. rachel Politely direct welcomed. Slightly short-tempered as well , but tempered from another good day of diving . __________________ Gilles http://www.dirrebreather.com
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13th May 2007, 15:06	#55 (permalink)
fireman rEvo combat swimmer Current Rebreather/s: rEvo Other CCR Other Rebreather/s: rEvo Other CCR Join Date: Nov 2006 Location: chicago Posts: 518	Re: Bringing an unconscious Rebreather diver up from depth I think Mike is an interesting character--good point though. Short of an ER doc/nurse at a busy large city hospital, I know I have done CPR more than everybody. If you haven't broken a few people ribs in the back of an ambulance, you haven't lived. Anyway-- If you don't have up to date CPR training, do it. For your family friends buddies etc. As the risk of your activities increases, So should the amount and level of emergency planning and equipement. On the EMS side if you are close to the EMS system, CPR, O2 and a cell phone might suffice. As one gets more remote an AED, airway adjuncts, Backboard. Truely remote cardiac drugs/ advanced training. I don't have the exact numbers in front of me, but I'm sure its on the web. So from my recollection-- Stopped breathing to cardiac arrest--5 min 4-6 min after cardiac arrest, brain starts dieing, this brain damage is irreversable. CPR will slow this down but you really need defibrillation and cardiac drugs. If the water is cold and the patient is young, onset of brain damage will be longer. So if a person is not breathing you don't have much time. If someone is seizing mouthpiece in-- could be a completely different story. Although people comming out of grand mal seizures are disoriented and frequently combative. Now that I think about it, Mike you are right, a clear flow chart, based on research and professional judgement is required. We need one for untrained OC buddies, all the way up to risky professional protocols. Let me start with an easy example--OC buddy, rec no deco, unconscious diver--turn BOV if available, surface asap--assess patient go into CPR mode. Training required--OC buddy must be familiar with Rebreather and BOV, diver rescue techniques, and CPR. And have a way to call for help. Thats a lot and its the "lay up" For the more complicated events, how hard is it to take a pulse of a diver with cold water gear for example. Is it worth trying. Perhaps in an overhead or extreme deco environment... By the way, never panic--because if your life is not on the line, there is nothing to panic about, and if it is, and you do--you will die. __________________ Heres to you Capt. Bill Never Forget, and stay safe everyone.
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13th May 2007, 18:56	#56 (permalink)
Tom Rose Still Learning Current Rebreather/s: Other CCR Home Build Other Rebreather/s: Prism Topaz Other CCR Home Build Join Date: Oct 2005 Location: USA,North Carolina Posts: 328	Re: Bringing an unconscious Rebreather diver up from depth Quote: (Originally Posted by fireman) By the way, never panic--because if your life is not on the line, there is nothing to panic about, and if it is, and you do--you will die. New instructions from the red cross...are keep the blood pumping is more important than the mouth to mouth..guess it has to do with moving oxygenated blood to the brain....of course in our cases...there is usually oxygen so we have both...but start with keeping the circulation going. Oh yeah, those ribs are damned fragile....but the alternative is really bad... Voice of experience from a rib cracker... Tom __________________ The 50-50-90 rule: Anytime I have a 50-50 chance of getting something right, there's a 90% probability I'll get it wrong the first time. www.atlimp.com
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14th May 2007, 01:52	#57 (permalink)
Simon Mitchell New Member Current Rebreather/s: MK 15.X Other Rebreather/s: Join Date: May 2005 Location: New Zealand Posts: 177	Re: Bringing an unconscious Rebreather diver up from depth Hello, Another good thread about a controversial topic. I have made my views on this known in the past, but in short, I agree with virtually everything Matty and Rachael have said. I suppose I should preface my further comments (because I also agree with Dr Mike's sentiments) that I manage airways for a living (I am an anesthesiologist), and that I am also a consultant diving physician and an experienced CCR diver. I have been involved in management of the aftermath of more than 20 episodes of unconsciousness underwater, and like a number of others here, have seen a few in the water for myself. Let's be clear about this (and it has already been said): there is NO single solution to this conundrum that will fit all scenarios, and priorities might conceivably shift under some circumstances. But as a general rule it is my strong belief that an unconscious diver needs to be removed from the water as soon as possible, and that this goal should take precedence over all other considerations in the vast majority of circumstances. This view is predicated on the certain knowledge that airways are difficult enough to manage and protect in the highly ordered and dry!! operating theatre environment let alone underwater in highly stressful chaotic circumstances. In this regard, Gilles, I agree with Matty that you are placing too much faith in your BOV / mouthpiece retainer system. To be fair I dive with exactly the same configuration as you (BOV with a Drager mouthpiece retaining strap), and I agree that they do seem effective (especially when you are conscious!). But my expectation of this arrangement is that it might give my buddy more time to notice my problem and effect a rescue before I drown, but not that it will allow him or her to keep me underwater in an unconscious state so that I can complete my deco, or ascend slowly etc. Another relevant issue that has not really been highlighted is that a dry airway is only half the battle. It would be no use to have a dry airway if you are not ventilating your lungs, and unconscious subject will not ventilate unless their airway is held open. It would be very hard to do this and assess the efficacy of your intervention underwater if the diver was breathing on a loop. I do admit that with a BOV the exhaust bubbles would be visible, but maintaining an open (and dry) airway would still be hard for any period of time. It follows from the above that, in general, I am against complicated algorithms that advocate analysis of the situation at depth, or trying to maintain a dry open airway for extended periods underwater. The instinctive response to an unconscious buddy should be to ask "what is the best way to get this diver out of the water as quickly as possible?". I am sympathetic to the view that if a rebreather diver has retained their mouthpiece and there remains a possibility they are breathing, then an aggressive pure oxygen purge of the loop can do no harm immediately prior to or during the taking / sending of the diver rapidly to the surface. The choice of "taking" or "sending" depends on an integration of the rescuer's perceptions of their own risk and the likelihood of an effective rescue at the surface if the victim is unaccompanied. I do admit that there may be some circumstances where an attempt to manage the airway underwater might be justified, such as an emergency in which there is no prospect of the diver reaching adequate surface support and it is too unsafe for the buddy to accompany the victim to the surface to manage the situation themselves. Unfortunately, such scenarios are likely to have a fatal outcome no matter what options are taken. Simon M Last edited by Simon Mitchell : 14th May 2007 at 04:18.
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14th May 2007, 02:14	#58 (permalink)
fireman rEvo combat swimmer Current Rebreather/s: rEvo Other CCR Other Rebreather/s: rEvo Other CCR Join Date: Nov 2006 Location: chicago Posts: 518	Re: Bringing an unconscious Rebreather diver up from depth Quote: Unfortunately, such scenarios are likely to have a fatal outcome no matter what options are taken. Thanks for contributing, have some green. Yeah sometimes the hardest thing is to let go. I have seen situations where we (firefighters) line up like Lemmings to try to save one of our own. Usually cooler heads prevail. And I would do it again. It has been said men go into battle not for god or country, but for the men standing next to us. I still assert that preplaning that is correlated to the risk of the dive is mandatory. Stay safe everybody. __________________ Heres to you Capt. Bill Never Forget, and stay safe everyone.
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15th May 2007, 17:34	#59 (permalink)
db8us Custom Title Allowed! Current Rebreather/s: Other SCR Other Rebreather/s: Other SCR Join Date: Sep 2005 Location: Germany Posts: 227	Re: Bringing an unconscious Rebreather diver up from depth Quote: (Originally Posted by decoweenie) Is this comment helpful when people are seriously trying to learn here ? And the intended insinuation that all Rebreather divers are solo divers is way off base and not freaking appreciated! No Phi, it is because nobody mentioned this obvious fact. I think we just need to be aware that we can only execute this option if we are NOT diving solo with breathers. Regards Michael (and i will not show you my butt :-) )
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15th May 2007, 17:46	#60 (permalink)
Tom Mount New Member Current Rebreather/s: Inspiration Classic Evolution Megalodon Sport Kiss Classic Kiss Optima Other CCR Other Rebreather/s: Other CCR Join Date: Jul 2005 Location: USA Posts: 96	Re: Bringing an unconscious Rebreather diver up from depth Quote: (Originally Posted by MHD) Simple review of 3 real cases 1 JasonM, showed problems at approx 110m early in dive, ascended by self to approx 30m, was escorted by another diver during ascent, went unconscious at 30m and was blown by buddy (who himself had significant deco obligation) to surface and recovered by boat crew. Was resus'd by crew and transfered to hospital. Showed signs of severe DCS hit among other symptoms. Has since made an almost full recovery. (Jason may say what his residual issues are I know he had some sometime back but no clue to there real extent, but involved a spinal hit I think) Key item here was that diver had significant DCS obligation, but made basically a straight ascent from 100 in the end. The cause for his problem is immaterial to the subsequent management of the deteriorating and finally unconscious divers, but the key was once on surface was recovered by boat crew almost instantly and air way safety and breathing re-established. But the key thing was that once he went unconscious his time in water where he could drown was minimal. Unconscious diver under water = future drowning victim Bent divers can be treated, dead divers can't be Case 2 Myron Wyntonik Grand mal seizure at 42m early in dive, lost loop, teeth clenched so unable to put reg in mouth. Was bought by divers straight to surface and back of boat where resus was commenced. Was resuscitated but had recursive drowning, and was choppered out and resus'd by para's on several more occasions. Was released from hospital and walking and basically physically fine the next day. Key element was that while air way was unprotected, total time was probably about 90 second with either loop out or breathing water. Again time is everything with an unconscious diver. Drowning is your worst enemy. Myron had no DCS symptoms, was chambered as a precaution for a AGE. Total time on bottom was less than 5 minutes so this is not unexpected Case 3 Rob Cook Grand mal seizure at 3m at end of dive, no deco obligation, Was in process of bailing out , but hadn't managed to get reg in by time of seizure, so breathed water, was instantly taken on board a boat and resus'd (ie brought to surface unconscious and not breathing). Choppered to hospital and released the next day. All 3 are successful cases where the air way was compromised. In at least 2 cases there was nothing you could have done to restore gas quality to loop, for varous reason I wont explain (it may of made no difference in the third either). The key is the longer the time underwater the unconscious diver spends the more likely they are to die. Very simple. These successful cases all have one thing in common. They got to the surface ASAP (all well less than 90 seconds from point of unconsciousness), and got subsequent help that meant they lived. Screwing around trying to solve other non important issues is the same is finding interesting ways to kill them. If you take 3 minutes to get diver with a unprotected air way to the surface (ie reg out) it is all over in practice. If you take 3 minutes to get a non breathing diver to the surface it is all over If you can not guarantee the diver is breathing, get them to surface, who cares what their loop is or there Deco obligation. The loop it is the most likely reason they went unconscious, so get them to the surface and breathing air ASAP. Every second you screw around it is more likely they will die. DCS can kill but drowning is faster. DCS can be treated post event, death is a little more hard to rectify. Drowning is the biggest risk at this point, manage that and you will have a hope. There are several stories floating around about people trying this and that underwater with a unconscious Rebreather divers, and they all result with the death of the Diver, the successful cases all have one common factor, minimum time with the air way compromised. There will always be the odd exception. but for me having known 2 of the above people and being full informed of the events (case 2 and 3), this the ultimate application of the K.I.S.S principal. Matthew Matt great job- As I had stated long ago in this discussion getting to the surface is the key element- DO NOT try to keep diver on loop = a drowning is eaisrer to treat than keeping a person breathing a hypoxic- hyperoxic, or hypercapnia mix
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