The UPMC Presbyterian Hospital in Pittsburg, Pennsylvania, is trying this May a new technique to save lives. For the trial of placing humans in suspended animation, all the blood of 10 patients with lethal wounds will be removed and replaced with a cold saline solution.

The replacement solution aims to cool the body and slow its functions to a stop and reduce the need for oxygen. Doctors prefer to call the procedure emergency preservation and resuscitation because suspended animation sounds like science fiction, lead surgeon Dr Samuel Tisherman told New Scientist.

The bases of the trials are similar effects achieved in two incidents. The first incident involved Swedish woman Anna Bagenholm who survived being trapped under a layer of ice in freezing water for 80 minutes in a skiing accident. The second incident involved Japanese Mitsutaka Uchikoshi who lived for 24 days without water or food when he entered into a state of hypothermic hibernation.

Dr Peter Rhee developed the technique after a successful test on pigs in 2000 and published the results in 2006. He induced fatal wounds on the hog by cutting their arteries with a scalpel and replacing the blood with saline that lowered the animal's body temperature to 10 degrees Celsius.

Pigs whose body temperature were left alone died, while those whose blood were replaced with saline and revived at medium speed had a 90 per cent survival rate, but some had to be given jolts on the heart. The surviving pigs showed no physical or cognitive impairment.

Tisherman said the technique would only be used as emergency measure on cardiac arrest patients with severe traumatic injury, open chest cavity and loss of at least 50 per cent of their blood. Such patients are considered with a 7 per cent survival rate. But such a technique could only done for a few hours only, although if successful, it could be a big step forward for mankind.