What are the dangers of shallow water blackout?
In both instances, the nature of the risk is clear: possible death. Even with successful resuscitation, complications including hypoxic brain damage and respiratory infection can occur. Following many recent deaths of competent swimmers, including swim team members, it cannot be said that the risk of SWB is improbable. Were you to have a syncopal episode and pass out underwater, you would beat high risk of death by drowning. A rapid, unconscious ascent also brings the risk of pulmonary over-expansion and decompression illness. Attempts at rescue by a buddy would put both you and your diving partner at risk.
What is the science behind shallow water blackout?
Shallow water blackout is a loss of consciousness caused by cerebral hypoxia towards the end of a breath-hold dive in shallow water. It is typically caused by hyperventilating just before a dive, which lowers the carbon dioxide (CO2) level and delays the diver’s urge to breathe. Because as you rise in the water column, pressure decreases and so the oxygen molecules become further spaced out. And so, it’s kind of like the oxygen’s more diluted. And so sometimes, divers will blackout as they’re approaching the surface. Hence shallow water blackout.An ascent blackout, or deep water blackout, is a loss of consciousness caused by cerebral hypoxia on ascending from a deep freedive or breath-hold dive, typically of ten metres or more when the swimmer does not necessarily experience an urgent need to breathe and has no other obvious medical condition that might have .The victim of hypoxic blackout may have been seen to be hyperventilating before the dive, and typically the blackout will have occurred some time after immersion, often without surfacing, and usually close to the surface. The victim is subsequently found unconscious or dead at the bottom of the water.
Is shallow water blackout related to freediving?
Hypoxic and shallow water blackouts happen for different reasons and under different circumstances – one is due to a lack of carbon dioxide, the other is due to dilute oxygen levels that can occur while freediving. Shallow water blackout is a loss of consciousness caused by cerebral hypoxia towards the end of a breath-hold dive in shallow water. It is typically caused by hyperventilating just before a dive, which lowers the carbon dioxide (CO2) level and delays the diver’s urge to breathe.
How long does it take to shallow water blackout?
Normally, drowning can take 5-10 minutes depending on a variety of factors. Shallow Water Blackout is faster. Within 2 minutes, you could experience brain death. Although drowning happens very quickly, it does take place in stages. The stages can take between 10 and 12 minutes before death occurs, or even more rapidly in the case of a child. People in water distress exhibit something called “Instinctive Drowning Responses.