Just a teaspoon of water can cause drowning

By SIMON COLLINS, Science Reporter


Drowning can be triggered by getting even a teaspoonful of water in the lungs and the way our bodies react means there may be nothing we can do to stop it.

Swallowing expert Dr Maggie-Lee Huckabee says the "gate" between the airway to the lungs and the alimentary canal, through which we swallow food and water, is lower in the throat in humans than in other animals.

The muscles in the throat help us to shape the air into speech. But we have less protection against food or water "going down the wrong way" into the lungs instead of the stomach.

Dr Peter Jones, medical director of Surf Lifesaving's northern region, says that when our nose and mouth get under water, our first instinct is to hold our breath.

"But you get to the point where you are becoming so low in oxygen that you open your mouth to breathe and you swallow water," he says.

The throat muscles respond automatically by blocking the entry to the lungs. But that only prolongs the lack of oxygen that would normally diffuse from the lungs to the bloodstream which carries it to all our vital organs, including the brain.

Within a few minutes, the brain becomes so starved of oxygen that we become unconscious.

As we lose consciousness, we lose control of the gate in the throat.

Water gets into our lungs, only worsening our lack of oxygen.

If we are rescued and resuscitated in time, we may escape with inflammation of the lungs. It is possible to survive on a ventilator while the body gradually clears out the excess water. However, if we are not rescued soon enough, lack of oxygen will quickly shut down the key organs.

Often the heart is one of the first to stop.

In those cases we will be dead in the water and resuscitation attempts are unlikely to work.

In other cases the heart may still be beating and resuscitation may keep us alive, but other organs - especially the brain - may be so damaged that we may die hours or days later.