What is the evidence of utility for intraosseous blood transfusion in damage-control resuscitation?

I (IO) access is an old technique for gaining entrance to the systemic circulation, which has received a general resurgence in the last 30 years. IO access takes advantage of the vascularity of cancellous bone, the spongy bone inside the hard outer compact bone. Cancellous bone is composed of a lattice work of spicules or trabeculae and hematopoietic red marrow, creating a porous framework. Clinically relevant cancellous bone used for IO access is located at the ends of long bones, such as the humerus, femur, and tibia, and the sternum. Originally, IO access was recommended for use in the resuscitation of critically ill children with difficult intravenous (IV) access. Over time, the clinical use of IO access increased, and its status of use has been elevated by such prestigious organizations as theAmericanHeart Association Committee on Advanced Cardiac Life Support. IO access is now recommended as a rescue technique to treat all critically ill patients regardless of age, when peripheral IVaccess is difficult or impossible. Damage-control resuscitation (DCR) is the mainstay of modern combat resuscitation of the injured soldier and has been extended to civilian casualty care. DCR differs from previous resuscitation methods by emphasizing a bloodand coagulation factor resuscitation strategy. In this strategy, blood is preferred over crystalloid for volume replacement, and coagulation factor therapy is aggressively begun early in the resuscitation process to head off the lethal triad of coagulopathy, acidosis, and hypothermia. The rate-limiting step for rapid implementation of this transfusion strategy as part of DCR is satisfactory IV access. Standard advanced trauma life support (ATLS) guidelines emphasize the need for the rapid placement of multiple large bore peripheral IV catheters. When that placement is difficult or impossible, ATLS recommends the use of IO access for infusions of crystalloid or blood until alternative venous access is achieved. The recommendation of IO access for blood transfusion is found not only inATLSguidelines but also in recommendations from the Infusion Nurses Society (INS). In linewith these recommendations, IO access is used as a rescue access in the prehospital implementation of DCR in the combat setting. The scientific and clinical evidence for the use of IO access is voluminous, as evidenced by the Scientific Bibliography provided by VidaCare, one of the large manufacturers of IO devices, and available in any routine literature search. However, direct scientific and/or clinical data to support the use of IO access for the purpose of blood transfusion in adult humans are very limited to anecdotal reports. For example, in one case report on an injured soldier, six attempts were required to place four IO catheters that were reportedly used to transfuse 2 U of packed red blood cells (pRBCs). A civilian report of successful blood transfusion by the IO route in a 79-year-old female cannot be used to establish a foundation for the general use of the technique in the adult population since the nature of the bone varies greatly by age, sex, and ethnicity. In this era of evidence-based medicine, the absence of good evidence supporting the use of IO access for the very critical function of blood transfusion in DCR places existing recommendations for its use in question. This lack of evidence is compounded by the clinical experience of the lead author. Multiple attempts to use IO access for blood transfusion, both in the civilian adult emergency setting and in combat casualty care, have repeatedly been unsuccessful. These attempts were made by highly experienced clinicians using specificmanufacturers’ guidelines for IO infusion. In all cases, at best, flow rates totally insufficient for resuscitation with blood products were established. The procedureswere aborted because the pressure required to achieve even these rates exceeded the tolerance of the infusion system at its connections. This incongruity between field experience and existing recommendations by the leading authorities has initiated this review.