Fiona Sharp death in Bonaire

[silent running]

Reaction to high PPO2 is a personal thing that changes with age, health, etc. My former SCUBA mate was an ex-navy diver, and they were chosen for a high tolerance to O2 so that they could use old-fashioned O2 rebreathers. He suffered pneumonia following an episode of hypothermia, and after his recovery he couldn't tolerate elevated PPO2 any more.

Yes, this has been my experience as well, high PO2 exposures are tolerated well by some, less by others. I dived 5hrs a day for 21 days in a row at 1.3 and only had a dry cough for a few minutes at the of the last few dive days.

Further on the subject of O2 exposure, it’s important to remember that CNS and OTU measurements are not well validated and were arrived at by theory and anecdote. They seem very conservative to me, based on my experience.

I have not heard of any recent clinical studies on high O2 exposure on divers or on hyperbaric patients. Anybody know of any?

 

[fsardone]

This article, What Happens After A Lack of Oxygen to the Brain? mentions that it’ll take from 30 to 180 seconds for someone suffering from lack of oxygen to pass out. Let’s say conservatively it takes 3 minute delay response at the onset of hypoxia for someone to pass out. At ascent rate of 10m/min, one would ascent 30 m before passing out.

Quoting from your linked article:
----<SNIP>-------------
A few seconds of oxygen deprivation won't cause lasting harm, so a child who holds his breath in frustration, a combatant choked unconscious during a Jiu-Jitsu, and a diver who needs a few extra seconds to come up for air are unlikely to experience brain damage. The precise timeline of anoxic brain injuries depends on a number of personal idiosyncrasies, including overall brain and cardiovascular health, as well as the level of blood oxygenation at the time of injury. Generally speaking, injuries begin at the one-minute mark, steadily worsening thereafter:

Between 30-180 seconds of oxygen deprivation, you may lose consciousness.
-------</SNIP>-----

It appears that the page is referring to system hypoxia which then will result in brain hypoxia.
The difference in breathing an hypoxic gas is that the gradient is toward desaturation of blood and haemoglobin of oxygen, which starts a desaturation process of the tissues as soon as the oxigen deprived blood and haemoglobin reaches the tissues. Same as breathing 100% to quickly remove N2. In this case you breathe He/N2 and remove O2 from tissues.

In these conditions a breath or maximum 2 is enough to loose consciousness and fall if standing, drown if diving. If oxygen is not quickly restored brain damage will result. This is proven by people breathing by mistake or to commit suicide 100% He.
Do not try it! You might not wake up!

 

[tursiops]

I believe these to be her bottles. I will try and get confirmation. And it is always possible that was was written on them is not what was in them.
View attachment 546293

I confirm these were her bottles, and the dil bottle had air in it, not 20/20.

 

[Wookie]

I confirm these were her bottles, and the dil bottle had air in it, not 20/20.

Well, there is lots of bad info out there, thanks for taking the time to verify.

 

[rjack321]

Quoting from your linked article:
----<SNIP>-------------
A few seconds of oxygen deprivation won't cause lasting harm, so a child who holds his breath in frustration, a combatant choked unconscious during a Jiu-Jitsu, and a diver who needs a few extra seconds to come up for air are unlikely to experience brain damage. The precise timeline of anoxic brain injuries depends on a number of personal idiosyncrasies, including overall brain and cardiovascular health, as well as the level of blood oxygenation at the time of injury. Generally speaking, injuries begin at the one-minute mark, steadily worsening thereafter:

Between 30-180 seconds of oxygen deprivation, you may lose consciousness.
-------</SNIP>-----

It appears that the page is referring to system hypoxia which then will result in brain hypoxia.
The difference in breathing an hypoxic gas is that the gradient is toward desaturation of blood and haemoglobin of oxygen, which starts a desaturation process of the tissues as soon as the oxigen deprived blood and haemoglobin reaches the tissues. Same as breathing 100% to quickly remove N2. In this case you breathe He/N2 and remove O2 from tissues.

In these conditions a breath or maximum 2 is enough to loose consciousness and fall if standing, drown if diving. If oxygen is not quickly restored brain damage will result. This is proven by people breathing by mistake or to commit suicide 100% He.
Do not try it! You might not wake up!

It takes more than 1 or 2 breaths. Not that there are any helium balloons left in the world, but pretty much every child has played with these consciously and without passing out.

 

[runsongas]

balloon helium is purposely blended to be a normoxic mix though. it isn't pure helium.

 

[hroark2112]

It takes more than 1 or 2 breaths. Not that there are any helium balloons left in the world, but pretty much every child has played with these consciously and without passing out.

Not every time. When it happened to me, it was 2 breaths then lights out. The second breath made me think I should get back on the boat, but I was out of it so fast I didn't even think to take a breath of fresh air.

Complacency kills - It's not just an empty threat!

 

[CuzzA]

Would an autopsy be able to reveal whether someone had an oxtox event?

 

[chillyinCanada]

I confirm these were her bottles, and the dil bottle had air in it, not 20/20.

Thanks.

 

[Remy B.]

The only thing I know about CCR is that of a try-dive so I don't.

This maybe been mention before but so many posts is easy to miss.

Dr. Fiona was deaf, do the DC integrated to the Inspiration CCR vibrate to make you aware of a alarm or is it just visual and sound ?
I know the Inspiration have a additional display that says Bailout supposedly hard to miss, or is this just a optional gadget ?