EFFECT OF LIPOSOME-ENCAPSULATED HEMOGLOBIN NEO RED-CELLS ON SEVERE HEMORRHAGIC-SHOCK

We induced shock by exsanguination and administered Neo Red Cells (NRC ) after 30 minutes to experimentally examine the efficacy of NRC on se vere shock with respect to hemodynamics and oxygen transport capacity. Seven beagles were used for this experiment. After intravenous anesth esia, intratracheal intubation was performed, and inhalation of 50% ox ygen was administered. Animals were exsanguinated through a vein at a rate of 30 mL/min. Animals showing systolic blood pressure of 60 to 69 mmHg were regarded as being in shock. After animals were left untreat ed for 30 minutes, NRC was administered. This was then repeated. Admin istration of NRC at a 1.5-fold dose compared to the exsanguinated bloo d volume was required for animals to recover from shock. Animals toler ated shock 3 times, but did not recover from the 4th shock. Although N RC with approximately one third the viscosity of whole blood was admin istered, vascular resistance was increased and cardiac output was decr eased, resulting in progression of heart failure. In addition, oxygen consumption increased with shock. NRC satisfied oxygen requirements by compensating for the decrease in cardiac output with an increase in A V difference, but erythrocytes were insufficient to increase differenc e in arterial and venous oxygen content (AV difference), and did not s upply sufficient volume of oxygen.