Drowning boy, 9, revived after an hour of CPR

Normally, first-aiders have just 30 minutes to restart a patient's heart and breathing, since any longer than this nearly always results in death.

On very rare occasions, people have come back after longer, but it is not common, and revival within eight minutes is necessary to prevent brain damage.

In today's case, emergency services were called out at 12.45 to the public outdoor pool in Colmenar del Arroyo (Greater Madrid region) after the unconscious child was lifted out of the water.

Using manual means and a defibrillator, ambulance staff worked on the child for an hour and were on the point of giving up when they discovered his heart was beating and he was breathing.

He has since been intubated and admitted to intensive care at Madrid's 12 de Octubre Hospital.

The next few hours, or possibly days, will be critical.

Whilst the survival rate of revived cardiac arrest sufferers is low in terms of percentage, many children and adults do live to tell the tale, making knowledge of CPR essential to everyone.

Recently, a 19-year-old man saved the life of a driver who crashed after suffering a heart attack by performing cardiac massage and mouth-to-mouth at the scene, and the victim is believed to have survived.

The photograph, by Madrid city council, shows a public swimming pool in the metropolitan area.