Carotid Sinus Reflex

[Oriskany Divemaster]

Ever heard of divers who suffer from CSR to a point where they black out/drown? Perhaps, a dry-suit diver with a too-tight neck seal? Does this happen? Is it common?

 

[DandyDon]

Do you have an accident to report or would you like this moved to Dive Medicine forum...?

 

[Thalassamania]

I've been told that it has occurred. I've never experienced or witnessed it.

 

[Oriskany Divemaster]

Do you have an accident to report or would you like this moved to Dive Medicine forum...?

No accident to report. Just research. So wherever you think I'll get the most accurate responses. Thanks.

 

[Teamcasa]

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A ScubaBoard Staff Message...

moved to diving medicine..

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[Ber Rabbit]

Several years ago there was a member who went by Snuggle here on the board. I don't remember if he posted his story or just told it around the fire at a GLWC meet-n-greet. He had bought a drysuit and took it out for a test dive, solo with no training. A fisherman found him unconscious but face up. Snuggle attributed the problem to his neck seal being too tight.
Ber :lilbunny:

 

[selkiesearchteam]

The first time I went for a dry suit dive I started to black out at about 20-30 ft (tunnel vision). I was very close to passing out when I signaled to the dive master with me and moved to a shallower depth where the feeling subsided. At the time, I attributed it to being nervous, or perhaps not inflating the suit enough that created a squeeze. Now, however, I wonder if it was instead the CSR since I seem to remember that the neck seal was rather tight.

 

[Duke Dive Medicine]

I could see how it could happen with an improperly fitted neck seal or hood. I would think that the diver would be so uncomfortable as to need to mitigate it before getting into the water, but maybe not.

Best regards,
DDM