Murdock, Larry R.

Pre-hospital use of whole blood is becoming increasingly prevalent in EMS and military medicine. Technologies to store, transport, warm up, and transfuse the blood are now available, and the outcome of whole blood transfusion seems to be superior to infusion of crystalloid solutions or plasma and at least equivalent to packed cells with plasma. The auto-transfusion tourniquet (A-TT®, Oneg HaKarmel Ltd., Tirat Carmel, Israel) is a non-invasive device that shifts the patient’s own blood from the legs to the core and blocks its reentry. The A-TT consists of an elastic ring made of a stainless-steel coil, wrapped by an elastic sleeve and pulling straps. When rolled up the leg(s), it squeezes the soft-tissues’ blood into the central circulation, and the ring stops the return of blood to the leg. The application time of the A-TT is less than 20 s per leg, and the A-TT transfers more than 500 mL of blood from each leg to the core. The auto-transfused blood is of the patient’s own type, has full oxygen carrying capacity, is normothermic, and is not anticoagulated. The device can be applied by a trained first responder, even during transport, and its use can be titrated to avoid overshooting the patient’s blood pressure. The device can be kept on the leg for up to 2 h, and as such, can serve as a bridge to blood or a bridge to definitive care. This paper is a hypothesis-generating review that defines the potential role of the A-TT in settings where blood is not available and is a call for others to help generate more data.