Hemorrhage is the most common cause of avoidable death due to trauma. While component resuscitation (i.e. platelets, plasma, packed red blood cells) is currently standard-of-care in civilian practice, reports from recent military conflicts suggest that whole blood resuscitation improves overall survival and reduces transfusion volume requirements. Until recently, leukoreduction filters have inhibited wide-spread introduction of whole blood because they remove platelets and result in a coagulopathic product. A novel platelet-sparing leukoreduction filter has become available and initial studies indicate its ability to preserve functional coagulation and suggest its therapeutic safety for whole blood transfusion. Further research is needed to assess the overall efficacy of this filter in terms of transfusion outcomes, product quality, shelf life, and storage conditions.
The ultimate goal of this project is to confirm the clinical safety of transfusing trauma patients with whole blood leukoreduced by a platelet sparing filter. More specifically, we aim to determine the effectiveness whole blood resuscitation vs. component therapy via 1) transfusion volume requirements; 2) variables known to reflect potential & actual clotting capacity
Prospective clinical trial. Inclusion criteria: all adult trauma patients presenting to Ronald Reagan University of California Los Angeles (UCLA) Medical Center with systolic blood pressure <100 due to suspected hemorrhage. Adult males will receive leukoreduced whole blood when available. Adult females will receive component therapy. Exclusion criteria: burn patients, patients with medical bracelets or other directives refusing blood transfusion (if known during emergent resuscitation), pediatric patients.
Volume and number of units are recorded of transfused products in both patient groups.
Blood clotting capacity is periodically assessed in study participants via thromboelastography (TEG). Venous blood samples are collected on admission, immediately post-operation, day 1 post-operation, and day 3 post-operation; samples are then loaded onto TEG analyzer. Reaction time (R), kinetics (K), alpha angle (angle), maximum amplitude (MA), and clot lysis time (CL) are recorded.
To date, 185 study participants (component therapy: n=179; whole blood therapy n=6) have been analyzed. Although statistically insignificant, total blood transfusion volume was less in whole blood vs. component therapy patients 4 hours after presentation (1925 mL vs. 3200 mL, p=0.35) and 24 hours after presentation (2512.5 mL vs. 4250 mL, p=0.161). Relative transfusion ratios were calculated by unit in each patient group. Platelets:packed red blood cells (4 hours: 0.2 vs. 0.5, p=1; 24 hours: 0.2 vs. 0.8, p=0.631) and fresh frozen plasma:packed red blood cells (4 hours: 0.6 vs. 0.6, p=1; 24 hours, 0.6 vs. 0.7, p=0.785) did not significantly differ between whole blood vs. component therapy patients respectively. Clotting capacity as measured by TEG did not significantly differ between the two groups on admission, post-procedure, nor post-op.
Preliminary results suggest that whole blood resuscitation might reduce total transfusion volume compared to standard component therapy. This is consistent with a prior study which demonstrated less transfusion volume required by combat casualties receiving warm fresh whole blood vs. those receiving component therapy only. Our findings are somewhat inconsistent with another study which showed no difference in transfusion volume required by trauma patients receiving modified whole blood vs. those receiving component therapy (note: when this study excluded traumatic brain injury, modified whole blood patients did, in fact, require less transfusion volume vs. component therapy patients).
Although no significant differences were observed in TEG between the two patient groups, our current sample size is small. Further enrollment will elucidate whether hemostatic potential is improved with whole blood resuscitation.
Currently, whole blood units can only be used up to 10 days before they are discarded. Previous work suggests this shelf life can be extended. Laboratory analysis (e.g. TEG & calibrated automated thromboelastography) will be performed on leukoreduced whole blood samples to determine how long hemostatic potential is maintained in hopes of preserving more samples for transfusion.
Hospital outcomes will be compared between the two study groups e.g. development of coagulopathy, infection, venous thromboembolism (VTE), multiple organ failure (MOF), and mortality. This will unveil whether whole blood transfusion improves patient prognosis.