Save it-don't waste it! Maximizing utilization of erythrocytes from previously stored whole blood.

BACKGROUND: Recent military and civilian experience suggests that fresh whole blood may be the preferred for treatment of hemorrhagic shock, but its use is limited by its 21-day shelf life. The red blood cell storage lesion and coagulation status of packed red blood cells (pRBCs) salvaged from expired whole blood are unknown. We hypothesized that pRBCs can be salvaged from previously stored whole blood. METHODS: Cold stored, low-titer, O-positive, nonleukoreduced, whole blood units were obtained at 21 days of storage. Erythrocytes were separated by centrifugation, resuspended in AS-3, and stored for 21 additional days as salvaged pRBCs. The red blood cell storage lesion parameters of microvesicles, Band-3, free hemoglobin, annexin V, and erythrocyte osmotic fragility were measured and compared with pRBCs prepared at the time of donation and stored in AS-3 for 42 days (standard pRBCs). In additional experiments, murine pRBCs were prepared from expired whole blood units and compared with those stored under standard conditions. Mice underwent hemorrhage and resuscitation with standard and salvaged pRBC units, and serum cytokines and free hemoglobin were determined. RESULTS: There were no significant differences in microvesicle formation or cell-free hemoglobin concentration between salvaged and standard pRBCs. There was decreased Band-3 and increased phosphatidylserine in the salvaged units as well as greater osmotic fragility. Salvaged pRBCs maintained consistent clot firmness. After hemorrhage and resuscitation in a murine model, salvaged pRBCs did not demonstrate increased serum cytokine levels. CONCLUSION: Salvaged pRBCs from previously stored whole blood accumulate the red blood cell storage lesion in a similar fashion to standard pRBCs and maintain consistent coagulability when reconstituted with plasma. Salvaged pRBCs are not associated with an increased inflammatory response when used for resuscitation in a murine model. Salvaged pRBCs may be a viable product for utilization in the treatment of traumatic hemorrhagic shock.

Evaluation of a Novel Fibrin Sealant Patch in Hemorrhage Control After Vascular or Hepatic Injury.

INTRODUCTION: Acute hemorrhage remains the leading cause of death in potentially survivable injuries. The use of topical hemostatic agents has increased over the last two decades with the evolution of damage control surgery. By 2008, the military widely adopted Combat Gauze as the hemostatic dressing of choice for compressible hemorrhage. The goal of this study was to compare the performance of a novel fibrin sealant patch to Combat Gauze in two clinically relevant models of hemorrhage. MATERIALS AND METHODS: Yorkshire swine underwent unilateral femoral artery puncture or a grade V liver laceration with timed free bleeding then received either the fibrin patch or Combat Gauze packing with 3 minutes of standardized pressure. Animals were then resuscitated to maintain a mean arterial pressure of 60 mmHg for 4 hours. Hemostasis, blood loss, resuscitation volume, survival, vessel patency, and hematologic parameters were evaluated. RESULTS: Hemostasis was equivalent in both groups after hepatic and vascular injury. Survival was 80% in the fibrin patch vascular injury group and 100% in all other groups. Hematologic parameters were not significantly different between treatment groups. Femoral artery patency was 80% in both groups after vascular injury. With simulated ambulation after vessel injury, 60% of the Combat Gauze group and 80% of the fibrin patch group remained hemostatic (p > 0.05). In simulated re-exploration with packing removal, all animals rebled after hemostatic product removal. CONCLUSION: There was no significant difference in hemostasis between a novel fibrin patch and Combat Gauze after extremity arterial or hepatic injury. This novel fibrin patch may have a clinical advantage over the Combat Gauze, as it can be left in the body, thereby limiting the potential need for reoperation.