Hyper and hypodynamic models of sepsis in guinea pigs

The acute metabolic response following experimentally induced sepsis can generally be classified as either hypodynamic ("low flow") or hyperdynamic ("high flow"). We have found that in conscious guinea pigs the bolus infusion of 10(10) live Escherichia coli bacteria can elicit either response, depending on the route of administration of the bacteria. Intravenous infusion results in the hypodynamic condition of septic shock in which oxygen consumption (VO2) is reduced to approximately 60% of the control level, plasma glucose is elevated 4 hr after infusion with a reversal to extreme hypoglycemia 12 hr after infusion, and body temperature is reduced by approximately 5 degrees C in 12 hr. In contrast, subcutaneous injection results in increased VO2, body temperature, and plasma glucose. In both models the concentration of cortisol, catecholamines and glucagon were elevated, but the responses were more pronounced in the hypodynamic model. In both cases, insulin concentration was decreased. These models of sepsis are useful because many aspects of response are comparable to man, they are simple to create, and they are consistent and reproducible.