Unknown Woody From “Dive Talk” DCS and Medical Journey

[dmaziuk]

M-values are chosen to produce (statistical probability of) X cases of clinical DCS per Y dives. The way probabilities work is a) 7.5K dives may well have been "his time" and b) the sample of dives and divers from which they are derived must be representative of Woody and his dive, for the numbers to work. Gradient factors (as defined by Baker, not to be confused with those of Shearwater) throw an additional wrench in the works: while the M-values chosen by Herr Dr. Buhlmann represent some X-in-Y, the effect of reducing them to .7 on GF High is "we think it's safer", and "undefined" for any value of GF Low.

Which makes all the speculation of what/why/how kinda moot: he got bent because no algorithm says you won't, they just say the likelyhood of that is "reasonably low" for somebody's definition of "reasonable".

 

[Blackwater Hunter]

Woody, according to his linked in profile, logged 7,500 dives. This one he got bent on. Plenty of divers do things a certain way for years and never get bit. I know I am guilty of doing things the way I was taught in 1980 and continue to do so today. I am doubtful the dehydration was the cause (or the only cause). That he mentioned it is why everyone is latching on to it like a dog with a bone.

It was most likely a confluence of things, fatigue, age, mild hypothermia, struggling with the restriction, his choice decompression algorithm (these are just models we think will keep us safe, and he was obviously wrong for that dive and that day).

It will be interesting to see if they release the computer profile if different models would correctly predict whether he would get bent. I am not an expert on deco by any means, but the Physiology is never wrong, the model just didn’t get it right.

I can agree to that. Everyone, including myself, wants to find that "silver bullet" that caused it. I forgot that many small issues can be just as severe as one big problem. DCS can be a very strange thing. Someone could blast through a deco obligation and never get bent, and another could get bent on a NDL dive with very conservative tables. Everyone is different so deco will affect every diver differently. It's extremely hard to keep up with so many variables.

I am happy that Woody is alive and well, and honestly besides the aforementioned dehydration, he didn't do anything wrong that we know of. I made a big deal about the restriction in my first post, but cave divers get stuck in restrictions all the time, and it was with a team of 3. Of course I say all of this from observation, and not from experience. I would rather learn what to do in an emergency through observation, not experience.

 

[cerich]

I can agree to that. Everyone, including myself, wants to find that "silver bullet" that caused it.

there is hardly ever a "silver bullet" that caused it, and anyone that claims to have found it , while they may believe it, are likely wrong.

Seriously, our bodies even lacking a 'defect" are variable day to day, how our gear is sitting, all kinds of stuff that seem like they wouldn't be the problem can be, and often combine to be it. Outside of insane profiles, these aggressive but not really or barely stupid higher risk profiles and they got bent are almost always gonna end up a mystery to all the causation factors.

Learn some of the things that may, try to avoid in mitigate in own diving but it can happen to anyone on any given day when doing aggressive tech deco dives. If someone sold you on the idea these can be done safely always if "you just follow the rules" they lied, or are too stupid to be telling you anything

 

[Blackwater Hunter]

there is hardly ever a "silver bullet" that caused it, and anyone that claims to have found it , while they may believe it, are likely wrong.

Seriously, our bodies even lacking a 'defect" are variable day to day, how our gear is sitting, all kinds of stuff that seem like they wouldn't be the problem can be, and often combine to be it. Outside of insane profiles, these aggressive but not really or barely stupid higher risk profiles and they got bent are almost always gonna end up a mystery to all the causation factors.

Learn some of the things that may, try to avoid in mitigate in own diving but it can happen to anyone on any given day when doing aggressive tech deco dives. If someone sold you on the idea these can be done safely always if "you just follow the rules" they lied, or are too stupid to be telling you anything

Biggest "rule" I was taught is "no rule completely eliminates risk". They're only there to mitigate it, but risk is never eliminated. Best thing is to know what to do for emergency scenarios, and to know that there are no perfect plans. Honestly intuition and initiative are the best traits to have because of this. Plans can fall apart but good intuition can save you.

Observe, Orient, Decide, Act

No dive is ever gonna be the same as the last, but we never notice the small details so they feel similar.

 

[L13]

Amex medical evacuation benefit would cover the flight, but must be arranged through them. The care afterward would not be covered.

https://scubaboard.com/community/threads/youtube-celebrities-worthless.641524/post-10165347

And all of it is covered by DAN. But they messed up and had to reimburse instead of paying up front like they should have.

 

[John the Pom]

M-values are chosen to produce (statistical probability of) X cases of clinical DCS per Y dives. The way probabilities work is a) 7.5K dives may well have been "his time" and b) the sample of dives and divers from which they are derived must be representative of Woody and his dive, for the numbers to work. Gradient factors (as defined by Baker, not to be confused with those of Shearwater) throw an additional wrench in the works: while the M-values chosen by Herr Dr. Buhlmann represent some X-in-Y, the effect of reducing them to .7 on GF High is "we think it's safer", and "undefined" for any value of GF Low.

Which makes all the speculation of what/why/how kinda moot: he got bent because no algorithm says you won't, they just say the likelyhood of that is "reasonably low" for somebody's definition of "reasonable".

It is the basis for risk management and safety engineering: the ALARP principle, "As Low As Reasonably Practicable". Zero risk isn't possible - even staying home doing nothing carries a certain risk.

 

[SlugLife]

DCS can be a very strange thing. Someone could blast through a deco obligation and never get bent, and another could get bent on a NDL dive with very conservative tables. Everyone is different so deco will affect every diver differently.

Also, the same diver could do an identical dive, under identical conditions. One day he's fine, the other he has DCS.

Lots of people are focused on Woody behind dehydrated. That's worth considering. However, I would guess Woody probably has at least 100 (perhaps 1000s) other deco dives, without a p-valve. So why this dive?

Seriously, our bodies even lacking a 'defect" are variable day to day, how our gear is sitting, all kinds of stuff that seem like they wouldn't be the problem can be, and often combine to be it.

The number of factors are practically endless. For example, someone I know well had severe headaches for many years, visited many doctors, tried many medications. However, finally one doctor did an allergy test, and discovered a food allergy. Once that food was cut out, the headaches were gone.

What caused Woody to get DSC this time could be something as random and unpredictable as what he had for lunch the previous day.

 

[SlugLife]

That's the part people tend to forget. With how experienced Woody is, you would think he would know that he was severely bent. Apparently Type 2 DCS can make any diver, no matter the experience, completely oblivious

I pointed similar out in another comment, and phrased it something like "the last person who should be diagnosing an impaired person, is the impaired person."

Any neurologist, pulmonologist, and EMT divers in this forum, are there field tests that can be used to determine the likelihood of severe DCS, Barotrauma, or air embolisms?

Good question. I suspect one of the difficulties, would be distinguishing DCS from other conditions, such as lack of sleep, low blood sugar, a hangover, dehydration, exhaustion, stress, etc. There are lots of things that can make one tired, less responsive, less able to communicate.

A lot of people harp on them for not recognizing the severity at the time. I want to agree, but I also wasn't there in person. I don't know what Woody actually looked like or said at the time. I've been tired, nauseous, slow, etc after a number no-deco of dives, so it's not always an immediate emergency just because a diver feels bad.

 

[Hiszpan]

DAN’s response

Not sure if correct thread, move if necessary.

 

[TravelGas]

Any neurologist, pulmonologist, and EMT divers in this forum, are there field tests that can be used to determine the likelihood of severe DCS, Barotrauma, or air embolisms? Any post dive injury that could go unnoticed. I've seen scenarios where DCS was extremely slow to start showing symptoms, but regardless were severe enough for emergency decompression.

There is no field test for DCS, DCS is purely a clinical diagnosis made by a Doctor, not a field Medic. However, a field Medic can form an index of suspicion of DCS by considering the following,
NOI/MOI, LOC, change in mental status, O2 Sat', GCS score, test PT Glucose level, Pupillary response, Vitals especially lung sounds in 8 fields, carefully monitor an unstable PT and response to interventions: O2 administration, IV fluids, BP, 12 Lead EKG, consulting with Medical Control, DAN, other Medical resource, depending on how remote you are.