The Study of Whole blood In Frontline Trauma (SWIFT) trial is led by NHS Blood and Transplant (NHSBT) and will involve 10 air ambulance charities across the country in partnership with the Ministry of Defence and Air Ambulances UK.
Air Ambulances have carried red blood cells since 2012. However during the SWIFT trial they will also carry ‘whole blood’. This is blood as it taken from the arm of a donor. It includes all the different blood components together, such as red blood cells, plasma, and platelets.
Red blood cells carry oxygen around the body. Plasma is the liquid part of your blood and it contains proteins which help blood to clot. Platelets are cell fragments that are essential for blood clot formation.
Previous studies, including on military casualties in Afghanistan, have indicated whole blood could have better outcomes for trauma patients, including a greater chance of survival.
Whole blood may work better because it contains platelets. Platelets are the cell fragments which help the blood to clot. Platelets are difficult to store – they have a short five-day shelf life, must be stored between 20C and 24C, and need constant gentle movement to help them stay oxygenated. This means they are very difficult to use outside of hospitals. Currently, Air Ambulance patients, and soldiers needing battlefield transfusions, can receive plasma and red blood cells, but not platelets.
Additionally, carrying and transfusing one blood product could also be lighter and simpler. It could enable faster treatment, at a time when every minute counts. And it could make the transfusion process easier and reduce risk, a crucial benefit in difficult and fast-moving incidents.
There is already past evidence that whole blood could lead to reduced mortality and reduce the amount of blood needed after patients arrive at hospital (3). However, only a full randomised controlled trial such as SWIFT can provide the definitive answers.
UK Air Ambulance operators
All of the blood used will come from group O Rh negative donors. This is the ‘universal donor’ blood type which is vital in emergency trauma care, when there is not time to check the patient’s blood type before transfusion is started.
Funding for the trial has been provided by NHSBT, the Air Ambulance charities, and the Ministry of Defence. The trial goes live tomorrow with the London Air Ambulance and will be rolled out to nine more Air Ambulance Services across the country over the next few months. The full list of air ambulance charities who are taking part in SWIFT is:
- Air Ambulance Kent Surrey Sussex
- Dorset and Somerset Air Ambulance
- Essex and Herts Air Ambulance
- Great North Air Ambulance
- Great Western Air Ambulance
- Hampshire and Isle of Wight Air Ambulance
- London’s Air Ambulance
- Magpas Air Ambulance
- North West Air Ambulance
- Thames Valley Air Ambulance
Over a two-year period, SWIFT will recruit 848 patients. One group of patients will continue to be given transfusions of red blood cells and plasma separately, with platelets given if needed after arrival at hospital. The other group of patients will receive transfusions of whole blood. The trial will compare survival and the amount of blood needed over the first 24 hours after injury.
Further improving trauma care would be of major importance. Major trauma kills more than 5,400 people every year in the UK. Pre-hospital red blood cell transfusions already save lives, with studies in military and civilian settings reporting a 12-14% absolute reduction in 30-day mortality.
This trial could enable a further reduction in mortality.