Hypocalcemia has direct and indirect effects on each portion of the lethal triad, supporting calcium's potential position as a fourth component in this proposed lethal diamond. The negative ramifications of hypocalcemia are intrinsically linked to components of the lethal triad of acidosis, coagulopathy, and hypothermia. While calcium plays several important physiologic roles in multiple organ systems, the negative hemodynamic effects of hypocalcemia are crucial to address in trauma patients.
It is interesting to note, that at least one cruise line has protocols in place for onboard blood donation and transfusion for catastrophic haemorrhage, with over 50 individuals treated in this way.Calcium is a divalent cation found in various physiologic forms, specifically the bound, inactive state and the unbound, physiologically active state. Another proposed advantage of using whole-blood in a trauma setting is the addition of a smaller volume of liquid administered, since reduced crystalloid fluid administration can be of benefit to arresting haemorrhage. However, research in the military setting has begun to show that using actual whole blood may have even more benefit, although this finding has yet to be formally tested in a civilian setting. Another major component of damage control resuscitation is the attempt to achieve rapid haemorrhage control by transfusion of fresh frozen plasma, packed red blood cells, and platelets in a 1:1:1 ratio, which mimics that of whole blood. This can involve damage control surgery where limited surgical interventions are used to minimise contamination and control the physical causes of haemorrhage until a patient is more able to undergo definitive interventions, either by being moved to a more appropriate place, or by regaining some physiological reserves. The aim of damage control resuscitation is to maintain circulating volume, control haemorrhage, and correct the lethal triad until definitive intervention is appropriate. Part of this process is the recognition that there is not always time to get a patient to a secure, well staffed and well stocked intensive care unit. Although there was no difference in the proportion of patients who underwent hysterectomy, the researchers found that tranexamic acid was able to significantly reduce death due to bleeding, especially in women who were given treatment within 3 h of giving birth.ĭamage control resuscitation is based on the principle that full, normal haemostasis does not necessarily need to be achieved at the first intervention. The WOMAN trial, published in The Lancet, examined the effect of early tranexamic acid administration versus placebo on mortality, hysterectomy, and other morbidities in women experiencing post-partum haemorrhage in a double-blinded, randomised trial. Use of fibrinogen concentrate was able to improve time to administration and various haemostasis measures.
The trial was terminated early for futility and safety reasons because a high proportion of patients randomly assigned to receive fresh frozen plasma needed rescue therapy and had an increased risk of multiple organ failure. In this issue of The Lancet Haematology, the RETIC trial compared coagulation factor concentrates with fresh frozen plasma in patients with major blunt trauma, an Injury Severity Score greater than 15, and confirmed plasmatic coagulopathy. Identifying the optimal pharmaceutical intervention for treating haemorrhage and trauma-induced coagulopathy has been the aim of two recently published articles. In cases of severe injury and massive haemorrhage, stopping the loss of blood can require use of clotting factors, fresh frozen plasma, and drugs such as tranexamic acid. When blood is lost, the greatest immediate need is to stop further blood loss.