The efficacy of intraosseous blood and ringer lactate in a rabbit model of hemorrhagic hypovolemia

Purpose: In this study, flow rates of intraosseously (IO) or intravenously (IV) administered fluids (blood or Ringer lactate) and their effects on vital signs were examined in a rabbit model of hypovolemia. Methods: Underanesthesia, 20 mL of blood was removed from each of the 36 New Zealand-type rabbits. Ten minutes later, each group of nine rabbits received one of four fluids by gravity flow from a height of 100 cm: blood via IO, Ringer Laktat (RL) via IO, blood via IV, or RL via IV. IO fluids were given in the proximal tibia through a 15 g needle placed with an EZ-IO instrument; IV fluids were given through a 22g catheter in the femoral vein. Vital signs were monitored for four hours after the infusion ended. Results: Flow rates were blood IO 2.6 mL/min, RL IO 3.4 mL/min, blood IV 3.2 mL/min, and RL IV 11.8 mL/min. Ten minutes after fluid administration ended, in the RL via IO group, heart rate was significantly slower than preinfusion; in the blood via IO group, body temperature was significantly lower than preinfusion, and in the blood via IO group, StO2 saturation was higher than preinfusion. Postinfusion respiratory rates within groups were not significantly different than preinfusion rates. Vital sign changes between groups were not significantly different. Conclusion: Fluids given by gravity feed through an IO needle were effective in treating hypovolemia in this rabbit model, but the flow of RL and blood were significantly slower through the 15g IO needle than the 22g IV catheter.