Fixed-Ratio Transfusion Feasible Following Trauma

Blood transfusion using a fixed ratio (1:1:1) of red blood cells (RBCs), frozen plasma (FP), and platelets is a feasible approach for patients with severe trauma, according to a new study.

Researchers at the University of Toronto (ON, Canada) and the Canadian Forces Health Services (Ottawa, Canada) conducted a randomized controlled trial of 78 trauma center patients with hypotension and bleeding who were expected to need a transfusion of over 10 RBC units during a 24 hour period. The patients were randomly assigned to a fixed-ratio or to a laboratory-results-guided transfusion protocol. The primary outcomes included feasibility (in terms of blood product ratios and plasma wastage), and safety, based on 28-day mortality and survival free of acute respiratory distress syndrome (ARDS).

The results showed that a transfusion ratio of 1:1:1 was achieved in 57% of patients in the fixed-ratio group, as compared with 6% in the control group. A ratio of 1:1 (RBC:FP) was achieved in 73% in the fixed-ratio group and 22% in the control group. The researchers found that plasma wastage was higher with the intervention protocol, with 22% receiving FP units, compared to only 10% of patients in the control group. The 28-day mortality and number of days free of ARDS were statistically similar between the groups. The study was published in the July 15, 2013, issue of the CMAJ.

“This balanced transfusion strategy aims to correct both the early coagulopathy of trauma and the volume status of patients in hemorrhagic shock, thus targeting preventable hemorrhage-related deaths,” concluded lead author Sandro Rizoli, MD, PhD, and colleagues from the University of Toronto. “The full and widespread implementation of such a protocol will challenge blood suppliers because of the increased demand (and wastage) of plasma.”

Hemorrhage linked to coagulopathy remains the leading cause of preventable in-hospital deaths among trauma patients. Use of a transfusion protocol with a predefined ratio has been associated with improved survival in retrospective studies in military and civilian settings, but such a protocol has its challenges, and may increase the risk of respiratory complications, lung injury, and organ failure. Another problem is that adoption of such a strategy requires thawing of frozen type AB blood, which is found in only 4% of donors.

Related Links:
University of Toronto
Canadian Armed Forces