SAMBA or Black-Out?

[johnnyong85]

Kindly need helps.
I stil dun understand the different between SAMBA & BLACK-OUT.
I'd refer to few videoclip in youtube but stil cant differentiate them. They seems to have same symptoms.
I love freediving and owez practising it when i got a chance to swim in a pool.
After knowing thr r hidden dangers like samba & blackout while doing freedive, better keep an eye on it.

let me share some clips here

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The explanation of this clip says it's a SAMBA. From the clip, the freediver seems to have "stokes?" at the beginning. And then the eyes of the freedivers "flip over" but manage to recover after few seconds.
So now, the questions:
1. When does a SAMBA happen?
2. If SAMBA happen to a freediver, wat shud v do, a CPR needed, any breathing tool needed?
3. Is thr any chance the freediver might not b recover? So... it's consider drown?

Here the next one

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The comments say it's a Black-Out. But the symptoms seems like the same with SAMBA lah...
The freediver have the same strokes beginning from 1:12 and then black-out at 1:22? He recover at 1:33?
The questions vil b the same as above.

Here is another one

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This 1 seems to b SAMBA. The freediver try a 2nd attempt. He began the lap from 3:00 and started to have strokes at 4:30, tat's a SAMBA.
So, the SAMBA happened after an apnea of 1 minute and 30 seconds.
The question:
1. I knw SAMBA happen bcos of the level of oxygen is too low. My record of static apnea is 5min 15seconds but i neva experience SAMBA. Yet, the SAMBA happened to a trained freediver jus right after 1minute and 30seconds of breath-hold. Why?
2. Why the audiences still clap thier hands after he get SAMBA? haha... joke. Perhaps to cheer him up!

One more

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The question:
1. It's a SAMBA or Black-Out? The freediver didn't show any symptom.
2. How did the rescuers knw he was in dangerous? Is it bcoz the freediver didn't hold ihs breath any longer?
3. What he bite in the mouth? (The yellow piece)
4. Is he recovered? Let's pray for him
A general question here. Does SAMBA & Black-Out caused any brain damage? If u joined PBSM or St.John b4, during ur schooling time, ur instrctor told u tat 4minutes of oxygen-lacked = brain-dead?
Lots of questions here. lol Hope u guys won feel irritating la and really appreciate if u reply.
Best regards,
Johhny...

[johnnyong85]

I dunno how to embed video here, some1 help?

[jome]

It's not a black and white thing. Different shades of gray, I'd say. Samba is just the early stages of BO...

It's usually called a BO when someone is clearly "out" for a period. Totally unresponsive and memory loss. But a tough samba doesn't look much different.

Surface bo's are sometimes hard to differentiate. But of course much clearer are BOs that happen in dynamic or deep diving - the person simply stops moving or loses control completely.

About the 4 minute rule - yes, 4 minutes without oxygen is dangerous for the brain. However, the brain is not "without oxygen" when you hold your breath. For an experienced freediver doing static the oxygen levels in the blood may not even drop noticeably in 4 minutes (I once tried this with an oxymeter and at about 3:45 it started to drop from 99% saturation). After it does start to drop, there are several compensatory mechanisms that prolong the period before the brain starts to suffer from hypoxia (mainly, increasing the bloodflow to the brain). But pushing your self to Samba or BO is not wise. We've seen that happen and these people are not quite brain dead, but it's safe to assume it's not good.

But after the BO, every second that you don't breathe is worse, you'd want to be rescued as swiftly as possible. After some minutes, serious brain damage is thought to occur.