Sometimes in medicine, what may seem like a new concept is simply a reboot of an old one with the additional bells and whistles that advancements in technology allow. The subject of resuscitating bleeding patients in the field is one such example. The 17th century findings of William Harvey cemented the importance of blood circulation to the brain and other vital organs. The following centuries have seen the development of transfusion practices that have shaped how we resuscitate sick and injured people in need of blood products.
As ever in trauma, much of what we do now is a result of lessons learned on the battlefields of the last century. World War 1 saw US forces pioneering the transfusion of whole blood. The Second World War continued in this fashion but also saw a shift towards the use of freeze-dried plasma and albumin as alternative volume replacements. Wastage of blood products in the Korean War led to a renewed impetus in US military research into alternative blood products and ways to increase the shelf-life of existing whole blood units.
For Vietnam, crystalloid was back in fashion, but also around the same time, blood fractionation techniques meant that individual components could more easily be given. Frozen red blood cell (RBC) units were trialled, but the thawing and preparation process proved to be resource-intensive, limiting the utility of this strategy.
By the time of the Iraq and Afghanistan conflicts of the early 21st century, an improved understanding of traumatic coagulopathy, the potentially harmful effects of excess crystalloid and the protective effects of plasma on vascular endothelium resulted in a push towards targeted higher ratios of fresh-frozen plasma (FFP) and platelets to RBC.
Current civilian damage-control resuscitation principles, borne of over a century of military experience have spilled over to the prehospital arena with many EMS services now having the will and capability to deliver prehospital blood product transfusions. Studies have demonstrated the feasibility of prehospital blood transfusions despite there still being a relative dearth of level 1 evidence in its support. The multicentre PAMPer study demonstrated a potential survival advantage in patients receiving prehospital plasma resuscitation whilst experience from London HEMS also demonstrated a significant reduction in prehospital mortality in patients receiving prehospital packed red cells. The evidence for its effectiveness notwithstanding, there are practical hurdles that also must be considered in terms of co-ordination with blood banks and supply and storage limitations
But blood transfusion is just one part of the haemostatic resuscitation package, and as the mantra goes, pouring water in a leaking bucket is ultimately futile. Temporising measures to stop bleeding in the prehospital environment have also benefited from military invention and/or refinement. Wound packing with haemostatic dressings and or tourniquet control of peripheral vascular injuries have been standard treatments for many years (if not centuries in the case of tourniquets). A number of innovations to tackle junctional and more central blood loss are also available on the market. The Combat Ready Clamp (CRoC) is a clamp that provides bidirectional pressure and can be applied to the iliacs, axilla and umbilicus to provide direct lower aortic compression. The SAM junctional tourniquet closely resembles the company’s pelvic binder but has the additional of 2 inflatable ‘Target Compression Devices’ which provide additional control of groin and (with the necessary strap adjustments) can also be used for axillary bleeding. Meanwhile the Junctional Emergency Treatment Tool (JETT) is an almost CroC-SAM hybrid with its adjustable groin compression pads fixed to a waist belt.
Ultimately it may be totally impractical to expect to deliver prehospital mass transfusion and the key may be quick and accurate identification of the bleeding source, with targeted haemostasis in-transit alongside pharmacological organ protection.
So no need for a prehospital version of our awesome MTP Scorekeeper just yet.
Obi Nnajiuba is a British surgical resident with a specialist interest in trauma, acute care, prehospital care, triage, mass casualty events and trauma systems. His postgraduate qualifications include an MSc in Trauma Sciences and membership of the Royal College of Surgeons of England. He is also a registered Motorsport UK physician, providing trackside advanced trauma care to competitors at world famous motor-racing circuits such as Brands Hatch, Goodwood and Silverstone.