Intraosseous hydroxocobalamin versus intravenous hydroxocobalamin compared to intraosseous whole blood or no treatment for hemorrhagic shock in a swine model.

OBJECTIVE

To determine if intraosseous (IO) hydroxocobalamin can improve systolic blood pressure (SBP) in a swine model after severe hemorrhagic shock.

METHODS

Thirty six swine (45-55 kg) were anesthetized, intubated, and instrumented with continuous femoral and pulmonary artery pressure monitoring and then hemorrhaged such that 30 percent of their blood volume was extracted over 20 minutes. Five minutes later, animals were randomly assigned to receive 500 mL IO whole blood, 150 mg/kg IO or intravenous (IV) hydroxocobalamin in 180 mL of saline, or no treatment and then monitored for 60 minutes. A sample size of eight animals per group was based on a power of 80 percent, an alpha of 0.05, and a small effect size to detect a difference in SBP between groups. Outcome data were analyzed using repeated measures analysis of variance (RMANOVA).

RESULTS

RMANOVA outcome analysis detected a significant difference between groups (p < 0.05). IO whole blood, IO hydroxocobalamin, and IV hydroxocobalamin groups were similar to each other, but significantly different compared to controls regarding SBP, mean arterial pressure (MAP), systemic vascular resistance, and heart rate. Differences in SBP and MAP were sustained throughout the experiment. At 60 minutes, the comparison among the groups, IO whole blood, IO hydroxocobalamin, IV hydroxocobalamin, and control, was the following: SBP 78.2 versus 83.7 versus 75.1 versus 55.3 mm Hg; MAP 62.7 versus 65 versus 60 versus 43 mm Hg. There was a significant interaction by time in lactate values (p < 0.01) such that control animal lactate values increased over time (3.3 mmol/L) compared to IO whole blood, IO or IV hydroxocobalamin treated animals (1.1, 1.6, 1.3 mmol/L).

CONCLUSIONS

IO hydroxocobalamin improved SBP, MAP, compared to no treatment and was similar to IO whole blood and IV hydroxocobalamin in this animal model of severe hemorrhage. Moreover, whereas serum lactate was improving in all treated groups, it was deteriorating in the control group.