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.
"The first hour following a traumatic injury or medical emergency is critical," said Christopher Denny, a doctor with the Helicopter Emergency Medical Service. "All research points to improved survival rates for critically injured patients that receive a pre-hospital transfusion.
"This is the first time this service will be available in New Zealand ... [but] there is evidence from other countries such as Australia, the United States and the United Kingdom, where this is a standard practice, to support the use of pre-hospital blood transfusions."
The blood transfusion trial is being run jointly between the New Zealand Blood Service, the Auckland Rescue Helicopter Trust, Auckland District Health Board and St John Ambulance.
The Auckland rescue helicopters service the greater Auckland region, with a population of 1.4 million people. They cover from Te Hana in the north to Meremere in the south, and Coromandel and the Gulf Islands to the east. It is estimated they will give transfusions of whole blood at least every two to three days.
One unit of O negative whole blood - to be replaced every two to three days - would be carried on board, Blood Service spokeswoman Asuka Burge said.
"The reason it's O negative is that is the universal blood type. In an emergency it can be safely transfused to anyone, regardless of their blood type."