HEMATOLOGIC SAFETY OF INTRAOSSEOUS BLOOD-TRANSFUSION IN A SWINE MODELOF PEDIATRIC HEMORRHAGIC HYPOVOLEMIA

Objective: To assess the risk of hemolysis, disseminated intravascular coagulation (DIG), or fat embolism syndrome (FES) with pressurized in traosseous (IO) blood transfusion following hemorrhage. Methods: A con trolled, repeated-measures, randomized animal study with blinded patho logic evaluations was conducted. Sixteen pentobarbital-anesthetized, i nstrumented immature swine underwent a 20-mL/kg hemorrhage into citrat e-phosphate-dextrose bags, then received autologous blood transfusion via a 16-ga IV catheter (eight), or via a 15-ga IO needle in the proxi mal tibia (eight) under maximal manual pressure using a 30-mL syringe. At baseline and atone hour and 48 hours posttransfusion, blood sample s were assayed for hemoglobin (Hb), schistocytes, free Hb in plasma, b ilirubin, lactate dehydrogenase, platelets, fibrinogen, and alveolar-a rteriolar O-2 gradient. Lung sections were examined for inflammation a fter hematoxylin/eosin stain, and for fat emboli after oil red-O-stain . Kidney sections were examined for inflammation using hematoxylin/eos in stain. Results: Though the IO transfusion rate of 21 +/- 6 mL/min w as slower than the IV rate of 35 +/- 5 mL/min (p = 0.0012), all the an imals returned to baseline blood pressure within 15 minutes and surviv ed. The presence of schistocytes and mildly elevated free Hb in plasma was noted in both groups at baseline and each time period, and was pr esumed to be due to sampling from the arterial catheter. All other lab oratory values remained within normal limits and without intergroup di fferences at any time period. No fat embolus was noted, and all lung a nd kidney specimens were free of inflammation. Conclusions: In this mo del, pressurized IO blood transfusion appears to be hematologically sa fe, i.e., without risk of appreciable hemolysis, DIC, or FES.