DCS or just plain exhusted?

[Bubbletrubble]

@danvolker: You are certainly entitled to your opinion. My previous post was not meant to represent the "mainstream agency" or DAN position. Please feel free to contact those entities to get their take on the matter. It was merely a description of what I saw (and still see) as the course of action that would minimize risk of injury to the diver.

Just to be clear, you are suggesting that the diver in question, who had such poor buoyancy control in the first place that she experienced a rapid, uncontrolled ascend to the surface from 100 fsw (after remaining at depth for 15 minutes), re-descend to 50 fsw to attempt to mitigate bubbling. How confident are you that such a diver can perform a purposeful, controlled ascent (replete with whatever depth/number/duration of stops are optimal)? Personally, I wouldn't place much confidence in her ability to maintain buoyancy control. How do we know that she was not improperly weighted (under-weighted), had not experienced a medical issue at depth, or that the ascent was not caused by gear malfunction? A distinct possibility remains that she will experience yet another rapid, uncontrolled ascent from depth. The risk of that scenario should be weighed against the risk of remaining at the surface, being monitored closely for DCI symptomatic onset, and having access to medical intervention.

Moreover, you are also assuming that unequivocal determination of AGE or no AGE can be made within 2 minutes of surfacing. From what I have gleaned from reading the scientific literature, symptomatic onset can certainly occur in the 3-10 minute window following surfacing.

Thanks for the dialogue here on the "Dive Medicine" forum. I'm a firm believer that, in the end, by questioning each other, we learn to be better, safer divers.

(I'd like to point out that I was able to compose this post without capitalizing or bold-facing any words for emphasis, your username excluded.)

 

[danvolker]

@danvolker:Just to be clear, you are suggesting that the diver in question, who had such poor buoyancy control in the first place that she experienced a rapid, uncontrolled ascend to the surface from 100 fsw (after remaining at depth for 15 minutes), re-descend to 50 fsw to attempt to mitigate bubbling. How confident are you that such a diver can perform a purposeful, controlled ascent (replete with whatever depth/number/duration of stops are optimal)? Personally, I wouldn't place much confidence in her ability to maintain buoyancy control. How do we know that she was not improperly weighted (under-weighted), had not experienced a medical issue at depth, or that the ascent was not caused by gear malfunction? A distinct possibility remains that she will experience yet another rapid, uncontrolled ascent from depth. The risk of that scenario should be weighed against the risk of remaining at the surface, being monitored closely for DCI symptomatic onset, and having access to medical intervention.

i was just going on the information supplied by the OP. The way I understood this, the diver in question had only the "one" bad bouyancy event...and had the presence of mind to go back down to 50 feet, then do a slow ascent to a safety stop depth, where she apparently had no trouble holding her depth for the 3 minutes....this is what the OP said.

The OP did not elaborate on the cause of the bad bouyancy event...we do not know if it was an equipment induced issue, like a inflator failure, or an accidental overfilling of the BC that she could not remedy in time....What we do know from the information supplied, is that she did not have any other notable problems on other dives--many of them shallow where bouyancy changes are most dramatic.

Given this information, I would tell her she did the right thing to go back down. It seems the point of the OP, was to ascertain whether she should have been given negative feedback for going back down and decompressing as she did. And I would argue vigorously, that if the information above is accurate, that she did the smart thing in going back down, and the mainstream DAN position of calling for help from the boat and then O2, would have likely caused damage....
I see this as Negligent for any of us to allow this nonsense to continue in it's present form.

Moreover, you are also assuming that unequivocal determination of AGE or no AGE can be made within 2 minutes of surfacing.

From what I have gleaned from reading the scientific literature, symptomatic onset can certainly occur in the 3-10 minute window following surfacing.

Maybe this is where you and I are not argueing the same issue....

I am not suggesting that a diver "with AGE" should try to go back down to decompress .....if it was a tech diver with pure O2, it would be an entirely different thread, a different arguement, and completly unrelated to this...


What the OP was discussing, was a diver that could not have had AGE the moment she hit the surface..there was not time for hypersaturation ( bubbling) to occur. After a minute to 2 minutes on the surface, the gas would hypersaturate, bubbles would form, and the best solution then for a recreational diver, would be the boat and O2.....But in this scenario, the one I would like to rant about , no AGE has occuured. The diver fixes the bouyancy problem immediatly at the surface, and goes straigh back down to 50 feet, then does slow ascent and safety stop. If her time on the surface was only 15 seconds, I feel confident that no chance of AGE would exist, and massive evidence of this exists if you research the Navy manuals and current saturation diving protocols.

Thanks for the dialogue here on the "Dive Medicine" forum. I'm a firm believer that, in the end, by questioning each other, we learn to be better, safer divers.

(I'd like to point out that I was able to compose this post without capitalizing or bold-facing any words for emphasis, your username excluded.)

Thanks for the opportunity to get out one of my favorite rants . And I'm sure you noticed I avoided the capitalizing and boldfacing

 

[Bubbletrubble]

i was just going on the information supplied by the OP. The way I understood this, the diver in question had only the "one" bad bouyancy event...and had the presence of mind to go back down to 50 feet, then do a slow ascent to a safety stop depth, where she apparently had no trouble holding her depth for the 3 minutes....this is what the OP said.

The OP mentioned that the diver spent an additional 15-20 minutes at a depth of 50 fsw. I'm not sure how "intelligent" a move that was.

The OP did not elaborate on the cause of the bad bouyancy event...we do not know if it was an equipment induced issue, like a inflator failure, or an accidental overfilling of the BC that she could not remedy in time....What we do know from the information supplied, is that she did not have any other notable problems on other dives--many of them shallow where bouyancy changes are most dramatic.

I think this highlights one point on which we disagree. You are assuming that whatever caused the rapid, uncontrolled ascent was no longer present once the diver breached the surface. I chose not to make that assumption.

Given this information, I would tell her she did the right thing to go back down. It seems the point of the OP, was to ascertain whether she should have been given negative feedback for going back down and decompressing as she did. And I would argue vigorously, that if the information above is accurate, that she did the smart thing in going back down, and the mainstream DAN position of calling for help from the boat and then O2, would have likely caused damage....
I see this as Negligent for any of us to allow this nonsense to continue in it's present form.

I'm not so sure that using the word "negligent" is appropriate in this instance. Negligence is a strong word. It connotes liability in the legal world.
I'd also have to differ with your characterization that my opinion is "nonsense." That's rather dismissive.

Maybe this is where you and I are not argueing the same issue....

I am not suggesting that a diver "with AGE" should try to go back down to decompress .....if it was a tech diver with pure O2, it would be an entirely different thread, a different arguement, and completly unrelated to this...

What the OP was discussing, was a diver that could not have had AGE the moment she hit the surface..there was not time for hypersaturation ( bubbling) to occur. After a minute to 2 minutes on the surface, the gas would hypersaturate, bubbles would form, and the best solution then for a recreational diver, would be the boat and O2.....But in this scenario, the one I would like to rant about , no AGE has occuured. The diver fixes the bouyancy problem immediatly at the surface, and goes straigh back down to 50 feet, then does slow ascent and safety stop. If her time on the surface was only 15 seconds, I feel confident that no chance of AGE would exist, and massive evidence of this exists if you research the Navy manuals and current saturation diving protocols.

It appears as though, at the point the diver breached the surface, you had already ruled out the possibility of AGE. I can see no other interpretation of your stance that her decision to re-descend was the correct one.
This is inconsistent with what exists in the literature. I would contend that ruling out AGE cannot be done reliably within a 10 minute period post-surfacing.

I appreciate having this discussion. Even though we disagree, I do believe that your rants serve the important purpose of sparking debate.

 

[danvolker]

The OP mentioned that the diver spent an additional 15-20 minutes at a depth of 50 fsw. I'm not sure how "intelligent" a move that was.

I think this highlights one point on which we disagree. You are assuming that whatever caused the rapid, uncontrolled ascent was no longer present once the diver breached the surface. I chose not to make that assumption.

The OP indicated no other bad bouyancy events. It did not read as though any more problems occurred like this--that whatever happened, was fixed, so to speak. Since this is all past tense, and we read that no other events occurred, you don't need or want to assume other bouyancy events occured. You can always make up a hypothetical, but this one was real, and it is a scenario that happens sometimes...It happens often enough for us to reinforce a response a diver should have, should something just like this occur again. It certainly will.

I'm not so sure that using the word "negligent" is appropriate in this instance. Negligence is a strong word. It connotes liability in the legal world.
I'd also have to differ with your characterization that my opinion is "nonsense." That's rather dismissive.

I did not mean this as dismissive to you at all.
My rant requires me to charicterize the agency positions as negligent, because they will be responsible for people purposely injuring themselves, due to poor understanding of gas physics and the effects of a rapid ascent. The agencies and DAN put this position and understanding out there. Smart people like yourself, expect that information from a knowledgeable and reputable body like DAN, or the concensus of training agency positions, should be accurate. In this instance, they are flat out wrong, they know it, and they refuse to change stance. Perhaps they think that a little more knowledge for recreational divers is too dangerous. I think that is sick.

If an instructor certifies a student that has terrible bouyancy skills, and is constantly doing rapid . uncontrolled ascents, clearly the instructor was at fault for certifying this student.

The DAN and Agency positions "should be" about what a reasonably skilled recreational diver should be doing. In this case, where a bouyancy accident occurred to a diver with normally good skils in this, the agency position should be to help that diver to prevent injury. Instead, their direction is to "cause injury".

It appears as though, at the point the diver breached the surface, you had already ruled out the possibility of AGE. I can see no other interpretation of your stance that her decision to re-descend was the correct one.
This is inconsistent with what exists in the literature. I would contend that ruling out AGE cannot be done reliably within a 10 minute period post-surfacing.

I believe the body of knowledge from commercial and military saturation diving is extensive and exactly relevant to this. For decades, saturation divers have known that you can do a rapid ascent, even from extreme depths, and then go immediately to a chamber do perform your deco in....the key to doing this without injury, is to get into the chamber before the 2 minutes or so is up, before hypersaturation occurs.
Our blood holds gasses in solution. Add pressure, it will hold alot more gas in solution. Remove the pressure, and the gas will have to be released as bubblles, but this does not happen the moment of pressure change. In the human body, in our blood, it takes normally 2 minutes or more--so my way of thinking about this is saying you should be back down to 50 feet or more, within a minute of surfacing. Apparently the girl did exactly this.

More importantly, if someone diving with this girl has kept her on the surface to rule out AGE, after the 1st minute or two, this desire to rule out AGE, would actually be causing the damage. There is a critical time window here. The return to 50 feet had to be immediate ( say 30 seconds to fix inflator or whatever, then begin descent..this would be easy)
.

I appreciate having this discussion. Even though we disagree, I do believe that your rants serve the important purpose of sparking debate.

Thanks for giving me this opportunuty ....And I do hope the OP gets my opinion back to the girl in question, that she did do the right thing.

 

[TSandM]

I think one of the things that seems murky here is that AGE is not necessarily (or even most often) related to venous bubbling. AGE is thought to occur primarily from lung barotrauma, and some mechanism that permits the entry of gas directly into the pulmonary venous circulation (and from there, directly into the arterial tree). Although venous bubbling may not have begun to occur on surfacing (and some of that will depend on precisely how the ascent was done), lung barotrauma may well have occurred, and symptoms of arterial bubbles may take several minutes to develop. I know I have read accounts of folks initially feeling odd, then developing paraplegia within a very few minutes from surfacing.

Lung barotrauma is most likely in precisely the conditions described in the original post -- an uncontrolled ascent from depth. Having experienced a few uncontrolled ascents myself (one from 70 feet) I can say that it's easy for me to imagine someone not having the presence of mind to keep breathing when out of control in that way. I would think that embolism would be the most likely and disastrous risk of such an event, especially if the diver was within NDLs. I'd have a hard time recommending such a person return to depth (although I did, after my 70 footer -- but in retrospect, I'm not sure it was the wisest possible course).

 

[danvolker]

I think one of the things that seems murky here is that AGE is not necessarily (or even most often) related to venous bubbling. AGE is thought to occur primarily from lung barotrauma, and some mechanism that permits the entry of gas directly into the pulmonary venous circulation (and from there, directly into the arterial tree). Although venous bubbling may not have begun to occur on surfacing (and some of that will depend on precisely how the ascent was done), lung barotrauma may well have occurred, and symptoms of arterial bubbles may take several minutes to develop. I know I have read accounts of folks initially feeling odd, then developing paraplegia within a very few minutes from surfacing.

Lung barotrauma is most likely in precisely the conditions described in the original post -- an uncontrolled ascent from depth. Having experienced a few uncontrolled ascents myself (one from 70 feet) I can say that it's easy for me to imagine someone not having the presence of mind to keep breathing when out of control in that way. I would think that embolism would be the most likely and disastrous risk of such an event, especially if the diver was within NDLs. I'd have a hard time recommending such a person return to depth (although I did, after my 70 footer -- but in retrospect, I'm not sure it was the wisest possible course).

Lynne,
I can't imagine you not remaining in control of your breathing in such an episode.
As you know, I like to exagerate to make my points , but I would like to split this kind of a bouyancy event into two classes of divers:

1. the group that "does not" panick, and always thinks as they go, and solving as they go..in this case, they would continue breathing, with an obvious emphasis on the exhaling....for most divers, this should be the natural response.
2. the group that "does" panick, that could potentially freeze up and not breath or exhale sufficiently in a rapid ascent scenario. This is a mindless panick, because all they have to do to prevent the catastropy they are afraid of ( the effects of rapid ascent) is to keep breathing and exhaling. Arguably, this is the group that either should never have been certified, or they are so new that they should not be in any depth of water without the instructor next to them. I would also argue that people prone to panick, should probably take a sport or happby other than diving..they can stil watch the underwater videos

Back in the 70's when I began diivng, all the good divers practiced free swiming emergency ascents, for when our j-valve reserves were insufficient to get us to the surface. Everyone I dove with back then, would practice doing free ascents from 100 feet, and it was easy, especially if you were wearing a dorky horse collar you could inflate with the co2, and ride it up Most of us hated those, and just swam up at a comfortable full speed cruising pace upward.
When BC's became standard in the 80's, then riding the BC up as fast as it would take you was the norm for the free ascent practice.
Now suddenly, a couple of decades later, the new understanding is that ascents half as fast as were commonplace in the old days, will cause lung expansion injuries.....
So either the gene pool was stronger back in the old days....Or, the current concerns are unwarranted for divers not prone to panicking.

 

[ianr33]

@danvolker:
Just to be clear, you are suggesting that the diver in question, who had such poor buoyancy control in the first place that she experienced a rapid, uncontrolled ascend to the surface from 100 fsw

You are assuming she had poor buoyancy control.

It's possible the cause was a dropped weightbelt or stuck on inflator.

 

[danvolker]

You are assuming she had poor buoyancy control.

It's possible the cause was a dropped weightbelt or stuck on inflator.

Which is what I thought as well, from the way the diving was described by the OP.

I have seen this happen to recreational divers, and they can't always sort out the problem before they could be on a rocket ride...but it does not have to mean injury...all it has to mean is they keep deep exhales going, as they rocket up, fix the problem quickly on the surface, and get back down. If they lost weights, this might be hard unless their buddy was smart enough to grab the weights and do a quick trip up, then a quick trip back down---which would be safe, but certainly against agency guidelines...Personally I think you should care more for your buddy than having concern for the advice of some pencil pusher at an agency that knows nothing about the situation you are presented with. For YOU, not for some statistical representation of a diver.

 

[Bubbletrubble]

You are assuming she had poor buoyancy control.

It's possible the cause was a dropped weightbelt or stuck on inflator.

@ianr33: OK. So let's say that the rapid, uncontrolled ascent was caused by a dropped weightbelt or a stuck-on inflator...

If the uncontrolled ascent occurred secondary to a dropped weightbelt, how long would it take to get another weightbelt with the correct amount of lead from the boat op? 1 min.? 2 min.? 5 min.? Bear in mind that danvolker is arguing that, if the diver has only been on the surface for 2 min. or less, then the safest course of action for her is to re-descend back down to 50 fsw.

If the uncontrolled ascent occurred secondary to a stuck-on power inflater, how many divers trained nowadays would feel comfortable re-descending to 50 fsw after disconnecting the BCD inflater hose? You and I know that it's no big deal to orally inflate the BCD. I know that I practice this skill, but what percentage of divers trained in the last 15 years practice this skill regularly? If placed in the shoes of the diver in this example, despite being absolutely comfortable with this skill, I would still choose to remain on the surface. I would probably be somewhat rattled by the uncontrolled ascent. I think I'd want to put myself in a situation where others could help me out if a serious medical issue presented.

In either causative circumstance (dropped weightbelt or stuck-on inflater), I'd be afraid that, even though I followed my training and kept an open airway during the ascent, I still could have experienced a pulmonary barotrauma event.

danvolker states that there are 2 classes of divers: those who have a tendency to panic and those who do not. (I'm paraphrasing here.)
I think it's rather naive to think one cannot get hurt if he/she is not the type to panic. Divers who do all the right things (dive conservatively, limit nitrogen-loading, moderate ascent rates, etc.) get hurt all the time. When we go diving, we take all of our medical issues from the surface with us. I could think of a number of different medical emergencies (specifically related to the rapid ascent) that might manifest upon re-descending to depth.

For all these reasons and the ones I've listed previously, I would still have to strongly disagree with danvolker's stance.

I'd like to reiterate that I do appreciate him voicing his opinion, though.

 

[danvolker]

@ianr33: OK. So let's say that the rapid, uncontrolled ascent was caused by a dropped weightbelt or a stuck-on inflator...

If the uncontrolled ascent occurred secondary to a dropped weightbelt, how long would it take to get another weightbelt with the correct amount of lead from the boat op? 1 min.? 2 min.? 5 min.? Bear in mind that danvolker is arguing that, if the diver has only been on the surface for 2 min. or less, then the safest course of action for her is to re-descend back down to 50 fsw.

I know you can't help yourself here, but remember, this is not your hypothetical....you are constrained by the actual circumstances ...whatever happened, we already know she dealt with it in a matter of seconds, and went right back down to 50 feet--which I would commend her for. I would have suggested a more staged return to the surface than just doing another 15 minutes at 50 and then a normal ascent with safety stop, but the real deal here is that if she went down within the few seconds the OP said she did, then there were no bubbles to resolve, and all you had was 100 to 50 feet....and this she dealt with by what she did..the bubble formation issue for her profile would not be that big for 100 feet to 50 feet, the real pressure change problems are going to be the 50 feet to the surface. Ideally, she should have gone back to 100, then done a slow ascent t 50, then hung out there for ten minutes, then begun a slow ascent to safety stop. But what she did, was much safer for "her", than the alternative of going straight to the boat, and potentially getting DCS because hypersaturation would have had time to occur....meaning some damage.

If the uncontrolled ascent occurred secondary to a stuck-on power inflater, how many divers trained nowadays would feel comfortable re-descending to 50 fsw after disconnecting the BCD inflater hose?

Again, this is not your story or my story, this is an event that really happened, about a girl who was very comfortable going right back down, and apparently not all that concerned or nervous about the event... and rightfully so.

You and I know that it's no big deal to orally inflate the BCD. I know that I practice this skill, but what percentage of divers trained in the last 15 years practice this skill regularly? If placed in the shoes of the diver in this example, despite being absolutely comfortable with this skill, I would still choose to remain on the surface. I would probably be somewhat rattled by the uncontrolled ascent. I think I'd want to put myself in a situation where others could help me out if a serious medical issue presented.

In either causative circumstance (dropped weightbelt or stuck-on inflater), I'd be afraid that, even though I followed my training and kept an open airway during the ascent, I still could have experienced a pulmonary barotrauma event.

I blame this concern you have on the agencies.... If they had not drastically lowered the teaching standards, they would have had a gene pool of students that would be fine with doing free ascents, and would never be afraid to breathe out as they ascended. Even though you may well be an excellent diver, the agency positions on this ascent business is designed to frighten all recreational divers away from the practice, because in today's world, many are certified while terrified in class, and this type of diver will never learn well, and can not be excpected to breathe appropriately in a rapid ascent emergency...You were exposed to the message, even though it was designed to protect others

On the other side of this discussion, I do not endorse running out of air and having to do a free ascent. Back in the j-valve days, there was a real need for this....today, between good gas management skills and good buddy skills, OOA scenarios should not involve emergency free ascents.....but accidents can happen, and the skill is worth knowing. I have had an inflator failure at depth, and have seen others have it....I was able to yank mine out well before it moved me more than a few feet upward, but I use a wing with only 18 pounds of lift, and 12 of it was involved in keeping me neutral at the time--- 6 pounds positive is not very threatening..there are plenty of divers that were "sold" BC's with 60 and even 100 pounds of lift....these can become rocket sleds, and the hundred pound lift BC's on a diver without much negative weight, could cause even someone comfortable with the high speed ascent skills, to end up with lung damage. But again, that is not the case that we are dealing with today

danvolker states that there are 2 classes of divers: those who have a tendency to panic and those who do not. (I'm paraphrasing here.)
I think it's rather naive to think one cannot get hurt if he/she is not the type to panic. Divers who do all the right things (dive conservatively, limit nitrogen-loading, moderate ascent rates, etc.) get hurt all the time. When we go diving, we take all of our medical issues from the surface with us. I could think of a number of different medical emergencies (specifically related to the rapid ascent) that might manifest upon re-descending to depth.

For all these reasons and the ones I've listed previously, I would still have to strongly disagree with danvolker's stance.

I don't think I can agree with this..Good divers don't get hurt unless they do something stupid, which can include diving with someone who is dangerous.

If you want to change the issue, again, and interject medical issues on to this girl, I am going to throw the bs flag

In the story we read about, there is no reason to assume medical complications as existing prior to the dive.

Moreover, this is another thread entirely. For instance, can a diabetic diver be a safe diver? Of course, if they are controlled as a diabetic, and plan their exertions and nutrition for the day well--and stick to it! If you are talking about an asthmatic, that is another issue all by itself, and this should have zero implications to healthy divers....

In fact, it is my feeling that healthy divers are already unfairly discrinimated against by by an industry trying to sell to medically unfit divers----to the tune of having the decompression tables adjusted for people who really should not medically be allowed to dive.....
25 % of all divers today, most likely have a PFO ( this is the percentage which occurs in the general population). These people should not be scuba divers, and are the class which is most often associated with what is improperly referred to as getting "undeserved DCS hits". These people "could" have the PFO repaired, or they could become freedivers....they should not be scuba divers.....but that would mean 25% less sales in dive gear, 25% less classes for instruction, 25% less spent on dive travel...
Screening if mandatory, would be expensive as well, and would keep plenty of healthy divers from deciding they can afford to take up diving.
The effects of the fudged tables, and the ideas on issues for rapid ascent, are "limiting" to healthy divers, and can actually cause harm to a good, healthy diver. This girl's issue is a case on point.