Comparison of fluid infusion rates among peripheral intravenous and humerus, femur, malleolus, and tibial intraosseous sites in normovolemic and hypovolemic piglets.

STUDY OBJECTIVES

To compare infusion rates from various intraosseous sites (tibial, medial malleolar, distal femoral, and humeral) and at a peripheral IV site under gravity and pressure flow in normovolemic and hypovolemic states.

DESIGN AND SETTING

A piglet model was used to assess rates of infusion under varying conditions in a university hospital animal laboratory. Analysis of variance was used to evaluate site differences.

PARTICIPANTS

Twenty-three Yorkshire-Landrace mix pigs (weight, 12 to 23 kg) were studied.

INTERVENTIONS

Animals were anesthetized and intubated before cannulation with 18-gauge bone marrow needles at intraosseous sites and 22-gauge Teflon catheters in peripheral vessels. Infusion rates under gravity and 300 mm Hg pressure were determined. Infusion rates under similar conditions were repeated in hypovolemic animals with acute bleeding of 25 mL/kg.

MEASUREMENTS AND MAIN RESULTS

Mean infusion rates (mL/min) for gravity versus 300 mm Hg pressure in normovolemic pigs were 13.1 versus 40.9 for peripheral IV, 11.1 versus 41.3 for humerus, 9.3 versus 29.5 for femur, 8.2 versus 24.1 for malleolus, and 4.3 versus 17.0 for tibia. Hypovolemia resulted in average decreased rates of 32%. Infusion rates were significantly different between sites and between normovolemia and hypovolemia (P = .0001).

CONCLUSION

Intravenous access is the most efficacious method of acute volume replacement. Intraosseous sites differ in the infusion rates obtained--descending order is humerus, femur, malleolus, and tibia, but each is a reasonable alternative for short-term vascular access.