HOW LONG CAN WE SURVIVE WITHOUT OXYGEN?
thomasyoy July 8th, 2008
Human beings can survive only for a few minutes without oxygen. This is because of the susceptibility of the brain cells. Even though the brain is only about 2 % of the body’s weight, it consumes about 20 % of the oxygen we breath in. Hence if oxygen supplied by the blood is stopped for a few minutes, the brain ceases its function resulting in death. We will lose consciousness in 8 to 10 seconds after the blood supply to the brain is cut.
Brain cells can survive for long periods without oxygen at very low temperatures, as oxygen consumption is reduced at that time. This technique called ‘induced hypothermia’ is made use of during major surgeries where other tissues can survive for long periods without oxygen and that is why it is possible to remove organs, from brain-dead persons, for transplantation.