Critically injured Auckland patients have a better chance of survival on their way to the hospital with rescue helicopters in the city now carrying blood for emergency transfusions.
In a New Zealand first, Auckland's rescue choppers, and a land-based rapid response vehicle, are carrying blood for pre-hospital emergency transfusions at the site of an accident.
Auckland Rescue Helicopter Trust chief paramedic Barry Watkin said you could not put a number on the lives the blood might save.
"With the blood you can keep a person alive to get to hospital. If you can buy that bit of time, you get a life saved."
The trial began on Friday and will run for three months. The Auckland Westpac rescue helicopters will carry one unit of O negative whole blood on board during the trial period.