A new clinical trial begins tomorrow (15th December), with Air Ambulance crews carrying ‘whole blood’ instead of separate red blood cells and plasma for the treatment of severely injured patients at risk of bleeding to death.
The SWIFT (1) trial is led by NHS Blood and Transplant and will involve 10 Air Ambulance charities across the country in partnership with the Ministry of Defence and Air Ambulances UK.
If the trial shows patient benefit, it could reduce trauma deaths in civilian accidents and also on the battlefield, and in any situation where delaying a transfusion by seconds or minutes could be critical.
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 (2). 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 – so 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.
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 only and then 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 Charity Kent Surrey Sussex (KSS)
- 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. (4) This trial could enable a further reduction in mortality.
Dr Laura Green, co-chief investigator for SWIFT and Consultant in Haemostasis and Transfusion Medicine at NHS Blood and Transplant, said: “The role of air ambulances in providing blood transfusions at the scene of an incident is crucial – delivering the most challenging treatments in the most challenging environments.
“Any delay to starting transfusion during traumatic blood loss can reduce the chances of survival. We hope that SWIFT will show there are logistical and procedural benefits in giving a blood transfusion of all of the components in a single bag – and ultimately improved outcomes for patients.
“We are grateful to be working in partnership with air ambulance organisations and the Defence Medical Services to drive innovation and provide even better care to critical patients. We are also incredibly grateful to our O Rh negative donors, whose universal donor blood is critical in trauma transfusion – including in this trial.”
Simmy Akhtar, Air Ambulances UK CEO said “We’re proud to support the SWIFT trial in collaboration with NHS Blood and Transplant and the Defence Medical Services. A number of air ambulance charities across the UK are directly involved with this trial and like them our vision aligns with the SWIFT trial, that together we will ensure the best possible chance of survival and patient outcome for everyone in need of lifesaving pre-hospital care. Air ambulance crews are continually striving to provide the highest level of patient care and we hope the results will ultimately improve trauma care.”
Professor Richard Lyon MBE, KSS’s Executive Director of Research and Innovation and Deputy Medical Director said: “As one of the earliest adopters in UK of pre-hospital blood product transfusion and one of the busiest Air Ambulances in the country, this trial is very exciting for KSS as it has the potential to improve the outcome of our most seriously injured patients. We have been involved in the planning of the SWIFT trial from the outset and look forward to being a key research site.”
- SWIFT stands for Study of Whole blood In Frontline Trauma.
- 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.
- Spinella, P.C., et al. Warm fresh whole blood is independently assosciated with improved survival for patients with combat-related traumatic injuries. s.l. : J Trauma, 2009. Cotton, B.A., et al. A randomized controlled pilot trial of modified whole blood versus component therapy in severely injured patients requiring large volume transfusions. s.l. : Ann Surg, 2013. Yazer, M.H., et al. Initial safety and feasibility of cold-stored uncrossmatched whole blood transfusion in civillian trauma patients. s.l. : J Trauma Acute Care Surg, 2016. Perkins, J.G., et al. Comparison of platelet transfusion as fresh whole blood versus apheresis platelets for massively transfused combat trauma patients (CME). s.l. : Transfusion, 2011.
- Major Trauma Care in England: report by the Controller and Auditor General. s.l. : National Audit Office, 2010. Shackelford, S.A., et al. Assosciation of prehospital Blood Product Transfusion During Medical Evacuation of Combat Casualties in Afghanistan With Acute and 30-Day Survival. s.l. : JAMA, 2017. Griggs, J.E., et al. Mortality of civilian patients with suspected traumatic haemorrhage receiving pre-hospital transfusion of packed red blood cells compared to pre-hospital crystalloid. s.l. : Sc and J Trauma Resusc Emergency Med, 2018.