Possible Role of Artificial Oxygen Carriers in Shock and Trauma

Abstract

Trauma is the most common cause of death in young individuals in the industrialized world. One third of all trauma deaths take place within minutes to hours after injury. In this patient group, hemorrhage is a common cause of death. One important part of early treatment in trauma is i.v. administration of crystalloid and/or colloid resuscitation fluids to prevent the development of hemorrhagic/hypovolemic shock. While such fluids can restore blood volume, they cannot transport oxygen to the tissues. Ensuing tissue ischemia leads to anaerobic metabolism and to accumulation of toxic metabolites. This can, in turn, develop into irreversible shock and death. It would thus be advantageous if resuscitation fluids given on the scene not only restored loss of blood volume, but also could carry oxygen and deliver it to the tissues. In hospital blood for transfusion is not always readily available and typing and crossmatching can be time-consuming and costly. Consequently, in the hospital setting and during emergency surgery a resuscitation fluid that could deliver oxygen could be of value. Hemospan, a newly designed hemoglobin-based artificial oxygen carrier, has been tested in two different large animal hemorrhagic shock models. Normalization of hemodynamic as well as metabolic parameters was achieved without any signs of the detrimental vasoactivity seen with earlier hemoglobin-based products. Survival time also increased, even in comparison with autologous blood transfusions.