Abstract
The purpose of this study is to evaluate the hemodynamics and oxygen transport capacity of liposome-encapsulated hemoglobin, named Neo Red Cells (NRC). Endotracheal intubation was made in 8 adult mongrel dogs weighing 10.0-13.0kg under intravenous anesthesia. Blood was extracted from the right femoral artery and NRC in the same amount was transfused. After blood exchange, the hemodynamics were investigated by inserting a Swan-Ganz catheter in the animal and oxygen transport capacity was assessed by performing blood gas analysis from time to time. From 59% to 95% of blood was exchanged with NRC. The dogs were divided into two groups according to the percentage of NRC exchanged: group 1-59%-86%, group 2-88%-95%. In every animal the cardiac index (CI) was found to have increased and the total peripheral vascular resistance index (TPRI) decreased and the rate of change of each was higher as the blood-NRC exchange rate increased. The CI increase was due to the TPRI decrease. Low viscosity of NRC is presumed to be the cause of TPRI decrease, which alleviated the burden on the heart. The A-V difference of oxygen content increased due to the increase of the oxygen transport efficiency of NRC which is more than that of natural erythrocyte. Because the CI and the A-V difference of oxygen content increased, oxygen consumption increased. Our conclusion is that NRC is more effective than natural red cells not only hemodynamically but also as a transport of blood gas.
