Changes in central hemodynamics during experimental septic shock in conscious rats.

This study describes the hemodynamic, metabolic, and respiratory effects of a 4-h continuous intravenous infusion of live Escherichia coli bacteria (10(9)/h) in conscious, unrestrained rats. The early response to bacterial infusion was moderate hypotension and a marked and sustained increase in heart rate and respiratory rate. During later stages of bacteria infusion a marked decrease in stroke volume and cardiac output was observed, while total peripheral resistance increased. Arterial blood gas measurements showed an early primary respiratory alkalosis, while later stages of bacteria infusion were accompanied by progressive development of metabolic acidosis. This small-sized animal shock model may be useful for further studies, particularly since conscious rats were used to avoid the influence of anesthesia upon the development of septic shock.