Static Apnea Blackouts

[yevgeny1974]

Hi there

I'm researching a presentation on hypoxic vs hypercapnic blackouts in static apnea. I am relatively new to the science of freediving. Any links to research or anecdotal evidence would be greatly appreciated!

Thanks

 

[efattah]

Hypoxic blackout in static apnea is very common, virtually every single blackout is a hypoxia blackout.

Hypercapnic blackout, to my knowledge, has only ever occurred during pure oxygen apnea. For a study on that, see the study done at Duke University with a title something like 'enriched oxygen breath holding'. In that case, they caused hypercapnic blackout most easily by doing stationary bicycle while holding the breath on pure oxygen. CO2 narcosis occurred at PaCO2 > 90mmHg, and CO2 blackout occurred about 90 seconds after CO2 narcosis began.

 

[Johan Andersson]

Some references that may be of interest (including the one Eric was referring to):

Vann RD, Pollock NW, Natoli MJ, Corkey WB. Oxygen enhanced breath-hold diving. Final report. Durham, NC: Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center; 2000 March 24, 2000.

Loss of motor control and/or loss of consciousness... [Int J Sports Med. 2007] - PubMed result

Alveolar gas composition before and after maximal ... [Undersea Hyperb Med. 2006 Nov-Dec] - PubMed result

Hypoxic syncope in a competitive breath-hold diver... [Aviat Space Environ Med. 2009] - PubMed result

Summary of 58 cases of loss of consciousness durin... [Med Sci Sports. 1976] - PubMed result

The physiology and pathophysiology of human breath... [J Appl Physiol. 2009] - PubMed result

I could provide pdf:s of these if you do not have access to the full text. If so, PM me your e-mail address.

/Johan

 

[yevgeny1974]

Thanks for your swift replies! Much appreciated - plenty to keep me reading there!