Intestinal vascular and central hemodynamic responses in the cat following i.v. infusion of live E coli bacteria.

Septic shock was induced in cats by i.v. infusion of live E. coli bacteria. The reactions of the series-coupled sections of the small intestinal vascular bed were followed continuously by a plethysmographic technique. Intestinal venous outflow was recorded using a drop counting technique. Intestinal venous outflow was recorded using a drop counting technique. The chest was opened and blood flow in the ascending aorta was followed electromagnetically. Pulmonary arterial blood pressure was recorded after direct cannulation. Following infusion of washed E. coli bacteria suspended in saline, a rapid early response was evident. This was characterized by arterial hypotension, unchanged aortic blood flow, pulmonary hypertension, and intestinal vasoconstriction. After 5-10 min a period of relative normalization followed. After 30-60 min a second phase, characterized by general circulatory deterioration, developed. The induced septic shock was initially characterized by a slight intestinal vasoconstriction. There was no accumulation of blood or fluid in the intestinal vascular bed; an isovolumetric state was thereby maintained in intestinal tissue throughout the experiments.