Treatment of massive hemorrhage with liposome encapsulated human hemoglobin (NRC) and hydroxyethyl starch (HES) in beagles

Abstract

The efficacy of NRC as a substitute for blood transfusion for treatment of acute, massive hemorrhage was evaluated in this study. Fourteen beagles, anesthetized with a mixture of 50% nitrous oxide, 0.97% sevoflurane and oxygen and ventilated by a respirator, were hemodiluted by withdrawal of 12 ml/kg of blood and infusion of isovolemic HES (hemodilution: HD) four times every 10 min. Then the animals were divided into two groups; an HES group, in which the same HDs were continued and an NRC group, in which the HDs were done with NRC. The hematocrit value decreased to 11% in the HES group after eight HDs and to 13% in the NRC group, which had a 3.9% NRCcrit value during the same period. In the NRC group, Cao2 decreased to 7.9 ml/min, which was significantly higher than the 5.9 ml/dl of the HES group. Oxygen consumption decreased to 56 ml/min in the HES group, but in the NRC group, it dropped to 74 ml/min, which was significantly higher than that of the HES group. Cardiac output increased to 1.2 times that of the control after eight HDs and arterial mean pressure decreased to approximately 60%. The above data indicated that NRC delivered sufficient oxygen to tissues, substituting for circulating red cells and maintained aerobic metabolism. Therefore, it should be possible to use NRC successfully for the treatment of cute, massive hemorrhage.