2 embolisms

[Mobile Diver]

A Tale of 2 Embolisms. A friend & I suffered Arterial Gas Embolisms (AGE) almost exactly a year apart, on very similar dives, on the same boat, in almost the exact same location, while we were diving together. Both dives:
1) @185fsw
2) Back gas was air
3) Short bottom times because the anchor was dragging
4) No computer violations
5) Onset of symptoms within 3-4 minutes
6) Paralyzed on 1 side – his left, my right
7) Fully resolved on surface O2 within 30 minutes
8) We both walked up on the dock when we got back
9) Both took a level 1 chamber ride as a precaution
10) Both have resumed diving with no aftereffects
A few differences:
1) My dive had 3-4 minutes bottom time; his was a true bounce dive
2) My ascent was slower due to the amount of scope on the anchor
3) I switched to 50% O2 @ 70fsw even though I didn’t need to as I wasn’t sure I could use the O2 hang reg because of the current. I was able to use it so I had quite a bit safety margin.
Posted for information purposes only. Informed, thoughtful comments are welcome.

 

[Kevrumbo]

http://www.scubaboard.com/forums/di...-another-cause-right-left-shunt-risk-dcs.html

ARTICLES | Journal of Applied Physiology

 

[treasurehunter]

I think you need to revise your risk management planning when you do dives below 130.
There definitely would have been Deco stops and/or accent rates to respect even with 4 minute bottom time.
I don't know if you have some training to do dives to that depth but if you do you both seem to be lacking in knowledge of deep diving physiology.
A surface supplied hanging deco regulator on a drifting boat sound like a really bad plan to begin with. A quick bounce dive also seem to put you in a rush to hit the bottom and ascend just as quickly and again not a good plan. Trusting your computer on a deep dive as you and your friend realized is also not a good plan.
I recommend if you want to do deep dives get the proper training by a reputable instructor, its well worth it and after you will learn to how to take calculated risks.

 

[decompression]

Firstly, thanks for posting, many wouldn't post knowing it will be picked apart by other members. Personally, there are many aspects of this dive that are in complete opposition to how I dive. But, I remind myself, to each his own.

I'm curious as to what the accent rates actually were, the amount of exertion before and during the dive and what algorithm you were diving.


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[Mobile Diver]

http://www.scubaboard.com/forums/di...-another-cause-right-left-shunt-risk-dcs.html

ARTICLES | Journal of Applied Physiology

Interesting.

 

[fsardone]

Well,
planning the dive in air and using 4 minutes bottom time with 3 minutes descent (so only 1 minute at depth) requires a mandatory stop at 10 feet, but a dive with 4 minutes at dept requires way more see plan below.

IMHO, in general it would be best not to go over own training level and experience, because sometime doing so might be fraught with danger due to the fact you do not know what you don't know. Today's equipment allows us an ease of reaching dangerous depths or decompression status that needs to be compensated by our own capability to adhere to limits.

The suggestion to revise your own risk management plan is a sound one.There might be a phisiological reason for this event (shunts and foramen issues), but might simply be that you ascended too quickly and violated deco stop.

I do tech diving and a bounce to 185 is usually done with EAN50 deco from 21 meters (60-70 feet sorry I am metric) and if I am staying more than 10 minutes at dept even 100% oxy at 6 meters 20 feet.

Dive safe, this might be a well deserved warning ...
Cheers

Fabio


========PLAN ONLY FOR DISCUSSION DO NOT USE FOR DIVING ========
DIVE PLAN
Surface interval = 5 day 0 hr 0 min.
Elevation = 0ft
Conservatism = + 2


[TABLE="width: 500, align: left"]
[TR]
[TD]Level[/TD]
[TD]Time[/TD]
[TD]Run
time[/TD]
[TD]Gas[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]Dec to 185ft[/TD]
[TD]
[/TD]
[TD](3)[/TD]
[TD]Air[/TD]
[TD]60ft/min descent.[/TD]
[TD]
[/TD]
[TD]
[/TD]
[/TR]
[TR]
[TD]Level 185ft[/TD]
[TD]3:55[/TD]
[TD](7)[/TD]
[TD]AiR[/TD]
[TD]1.38 ppO2, 185ft ead[/TD]
[TD] :shocked2: LESS THAN 4 MIN AT DEPTH![/TD]
[TD]
[/TD]
[/TR]
[TR]
[TD]Asc to 30ft[/TD]
[TD]
[/TD]
[TD](13)[/TD]
[TD]Air[/TD]
[TD]-25ft/min ascent[/TD]
[TD]
[/TD]
[TD]
[/TD]
[/TR]
[TR]
[TD]Stop at 30ft[/TD]
[TD]1:48[/TD]
[TD](15)[/TD]
[TD]Air[/TD]
[TD]0.40 ppO2, 30ft ead[/TD]
[TD]
[/TD]
[TD]
[/TD]
[/TR]
[TR]
[TD]Stop at 20ft[/TD]
[TD]7:00[/TD]
[TD](22)[/TD]
[TD]Air[/TD]
[TD]0.34 ppO2, 20ft ead[/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[/TABLE]

Surface (28) Air -3ft/min ascent.

Off gassing starts at 84.2ft

OTU's this dive: 14
CNS Total: 5.5%

 

[Basking Ridge Diver]

Well,
planning the dive in air and using 4 minutes bottom time with 3 minutes descent (so only 1 minute at depth) requires a mandatory stop at 10 feet, but a dive with 4 minutes at dept requires way more see plan below.

IMHO, in general it would be best not to go over own training level and experience, because sometime doing so might be fraught with danger due to the fact you do not know what you don't know. Today's equipment allows us an ease of reaching dangerous depths or decompression status that needs to be compensated by our own capability to adhere to limits.

The suggestion to revise your own risk management plan is a sound one.There might be a phisiological reason for this event (shunts and foramen issues), but might simply be that you ascended too quickly and violated deco stop.

I do tech diving and a bounce to 185 is usually done with EAN50 deco from 21 meters (60-70 feet sorry I am metric) and if I am staying more than 10 minutes at dept even 100% oxy at 6 meters 20 feet.

Dive safe, this might be a well deserved warning ...
Cheers

Fabio


========PLAN ONLY FOR DISCUSSION DO NOT USE FOR DIVING ========
DIVE PLAN
Surface interval = 5 day 0 hr 0 min.
Elevation = 0ft
Conservatism = + 2


[TABLE="width: 500, align: left"]
[TR]
[TD]Level[/TD]
[TD]Time[/TD]
[TD]Run
time[/TD]
[TD]Gas[/TD]
[TD][/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[TR]
[TD]Dec to 185ft[/TD]
[TD]
[/TD]
[TD](3)[/TD]
[TD]Air[/TD]
[TD]60ft/min descent.[/TD]
[TD]
[/TD]
[TD]
[/TD]
[/TR]
[TR]
[TD]Level 185ft[/TD]
[TD]3:55[/TD]
[TD](7)[/TD]
[TD]AiR[/TD]
[TD]1.38 ppO2, 185ft ead[/TD]
[TD] :shocked2: LESS THAN 4 MIN AT DEPTH![/TD]
[TD]
[/TD]
[/TR]
[TR]
[TD]Asc to 30ft[/TD]
[TD]
[/TD]
[TD](13)[/TD]
[TD]Air[/TD]
[TD]-25ft/min ascent[/TD]
[TD]
[/TD]
[TD]
[/TD]
[/TR]
[TR]
[TD]Stop at 30ft[/TD]
[TD]1:48[/TD]
[TD](15)[/TD]
[TD]Air[/TD]
[TD]0.40 ppO2, 30ft ead[/TD]
[TD]
[/TD]
[TD]
[/TD]
[/TR]
[TR]
[TD]Stop at 20ft[/TD]
[TD]7:00[/TD]
[TD](22)[/TD]
[TD]Air[/TD]
[TD]0.34 ppO2, 20ft ead[/TD]
[TD][/TD]
[TD][/TD]
[/TR]
[/TABLE]

Surface (28) Air -3ft/min ascent.

Off gassing starts at 84.2ft

OTU's this dive: 14
CNS Total: 5.5%

Interesting - you must be using a conservative setting?

I used Multi Deco - 0 conservative setting - 185 feet - 7 min run time gives 3:55 min @ 185 feet.
50 second stop at 30 feet
2 min stop at 20 feet
3 min stop at 10 feet
total run time is 18 mins using air

 

[fsardone]

Interesting - you must be using a conservative setting?

I used Multi Deco - 0 conservative setting - 185 feet - 7 min run time gives 3:55 min @ 185 feet.
50 second stop at 30 feet
2 min stop at 20 feet
3 min stop at 10 feet
total run time is 18 mins using air

I am using VPM B in multideco conservativism 2 and min depth deco stop 6 metres because I always decompress 100% ppO2 1.6 from tech dive. For the discussion I did not bother change. For air I would lower the min depth to 3 metres unless sea state >2 in which case holding 3 meters might be an issue ...

In oxy 6meters or 3 does not make a difference siche ppN2=0 but it would lower the bubbling risk since PA=1.6 bar against 1.3 without changing the total offgas time. Not true with air.

Cheers

Fabio

 

[DogDiver]

Wow 185 feet on air. Enough said.


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[Nuribromanski]

Wow 185 feet on air. Enough said.


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185 is above the 1.4 mod, what's the problem?

There definitely would have been Deco stops and/or accent rates to respect even with 4 minute bottom time.

yeah, but what OP said was the 70' stop wasn't required. maybe u could stick to what OP said rather than guessing from ur assumption on OP's training??

A surface supplied hanging deco regulator on a drifting boat sound like a really bad plan to begin with.

do u know if OP had enough 50% & air in gas plan to deco out w/o the O2 he hung at 20'? if u don't know for sure, kinda makes u sound clueless, no?

TA quick bounce dive also seem to put you in a rush to hit the bottom and ascend just as quickly and again not a good plan.

ur really eager 2 make this into a situation u have in ur mind, but not what the OP said: dives were cut shorter than planned bc anchor was dragging & they elected 2 abort in each case.

i guess DIR mean make up facts and then comment on them