Pulmonary vascular reactions in experimental septicemia, A preliminary report.

Septicemia was induced in cats by infusion of live E. coli bacteria into the inferior vena cava, the portal vein or the aortic arch. Systemic arterial blood pressure, aortic blood flow, pulmonary arterial blood pressure, intestinal blood flow and portal venous pressure were recorded continuously and arterial platelet and white blood cell counts and acid-base balance measured at intervals. Infusion of E.coli into the inferior vena cava induced an initial response characterized by systemic pressure reduction, unchanged or increased aortic blood flow and pulmonary hypertension. Intestinal blood flow decreased moderately, while portal pressure remained unchanged. The arterial infusion evoked a similar response. After portal infusion there was a more pronounced increase of aortic blood flow, a significantly less elevation of the pulmonary artery pressure, and the intestinal blood flow was maintained. The changes induced in arterial acid-base balance or in platelet and white cell counts were not influenced by the route of administration. It is concluded that the route of administration of bacteria is of importance when considering the relevance of experimental data to clinical septic states.