Treatment of hemorrhagic shock with intraosseous administration of crystalloid fluid in the rabbit model.

Intravenous access can be very difficult to obtain in small hypotensive infants. We studied the ability of the intraosseous route to accept a large volume of resuscitation fluid administered to hypovolemic rabbits. Hypotension induced by withdrawing one-third of the blood volume of rabbits was treated by infusion of saline, IV or intraosseously. A control group was bled, but received no saline. All three groups experienced a drop in mean arterial blood pressure (MAP) to at least 50% of the prebleed baseline value. Also, all groups' heart rates dropped to between 90 and 95% of prebleed baseline values. A ten-minute infusion of a saline volume equal to three times the volume of blood removed reversed hypotension equally by the intraosseous and IV routes. After one-half of the fluid was administered, the MAP was 107 +/- 4% and 104 +/- 11% of baseline in the intraosseous and IV groups, respectively. In contrast, the control group had a MAP of 70 +/- 8% of baseline at the same time. At the end of the fluid bolus the intraosseous group had a MAP of 97 +/- 3% of baseline and the IV group a MAP of 99 +/- 8%. The control group continued to have a low MAP of 72 +/- 6% of baseline. Heart rates rose during fluid administration in both the intraosseous and IV groups, reaching 103 +/- 2% and 99 +/- 3%, respectively, at the end of fluid administration. The control group was 88 +/- 2% of baseline at the same time. The differences between the treatment groups and the control group were significant at the .05 level. The intraosseous route will allow sufficient flow of fluid to rapidly reverse hypotension secondary to hemorrhage in a small mammal (ie, the rabbit).