Hematologic Safety of Intraosseous Blood Transfusion in a Swine Model of Pediatric Hemorrhagic Hypovolemia

Abstract

To assess the risk of hemolysis, disseminated intravascular coagulation (DIC), or fat embolism syndrome (FES) with pressurized intraosseous (IO) blood transfusion following hemorrhage. A controlled, repeated-measures, randomized animal study with blinded pathologic evaluations was conducted. Sixteen pentobarbital-anesthetized, instrumented immature swine underwent a 20-mL/kg hemorrhage into citrate-phosphate-dextrose bags, then received autologous blood transfusion via a 16-ga i.v. catheter (eight), or via a 15-ga IO needle in the proximal tibia (eight) under maximal manual pressure using a 30-mL syringe. At baseline and at one hour and 48 hours posttransfusion, blood samples were assayed for hemoglobin (Hb), schistocytes, free Hb in plasma, bilirubin, lactate dehydrogenase, platelets, fibrinogen, and alveolar-arteriolar O2 gradient. Lung sections were examined for inflammation after hematoxylin/eosin stain, and for fat emboli after oil red-O-stain. Kidney sections were examined for inflammation using hematoxylin/eosin stain. Though the IO transfusion rate of 21 +/- 6 mL/min was slower than the i.v. rate of 35 +/- 5 mL/min (p = 0.0012), all the animals returned to baseline blood pressure within 15 minutes and survived. The presence of schistocytes and mildly elevated free Hb in plasma was noted in both groups at baseline and each time period, and was presumed to be due to sampling from the arterial catheter. All other laboratory values remained within normal limits and without intergroup differences at any time period. No fat embolus was noted, and all lung and kidney specimens were free of inflammation. In this model, pressurized IO blood transfusion appears to be hematologically safe, i.e., without risk of appreciable hemolysis, DIC, or FES.