[Hyperdynamic state induced by continuous infusion of E. coli endotoxin in dogs]

It is well established that septic shock is caused by Gram-negative endotoxemia, and is characterized by hyperdynamic state being observed in the early stage of shock. This study is designed to elucidate the hemodynamic and metabolic changes induced by continuous infusion of small amount of endotoxin in the dog, with special reference to the existence of hyperdynamic state. Seven mongrel dogs were continuously infused with 10 micrograms/kg/day of E.coli endotoxin for 4 days under fasted, awake condition. All animals revealed mild hypodynamic state with severe catabolic responses in protein-energy metabolism. In contrast, 11 dogs infused with 36kcal/kg/day of glucose and 10 micrograms/kg/day of endotoxin showed marked increase (+30%) in cardiac index, and decrease in mean arterial pressure as well as total peripheral resistance, indicating the presence of hyperdynamic state. Metabolic studies indicate mild catabolic response. Administration of fat emulsion instead of isocaloric glucose has resulted transient hyperdynamic state, but failed to maintain this condition. In conclusion, it is possible to produce hyperdynamic state similar to that seen in septic shock by continuous administration of small amount of endotoxin in the dog, provided proper amount of glucose is supplied.