London's Air Ambulance to carry blood

London's Air Ambulance is to become the first service of it's kind in the UK to carry blood.

Doctors say new technology developed by the army will help it respond to the most serious incidents and accidents across London.

Normal saline has been used as an alternative but, as it does not carry oxygen, it is not the ideal resuscitation fluid.

Blood carries oxygen which is delivered to major organs including the brain.

A pre-hospital blood transfusion may improve the patient's chance of survival.