Gram-negative bacteremia produces both severe systolic and diastolic cardiac dysfunction in a canine model that simulates human septic shock.

Abstract

A canine sepsis model that simulates the human cardiovascular response to septic shock was produced in 10 conscious unsedated dogs by implanting an Eschichia coli-infected clot into the peri- toneum, resulting in bacteremia.By employing serial, simulta- neous measurements of radionuclide scan-determined left ven- tricular (LV) ejection fraction (EF) and thermodilution cardiac index (CI), the end-diastolic volume index (EDVI) was calculated (EDVI = stroke volume index + EF).By using three different methods of quantifying serial ventricular performance (EF, shifts in the Starling ventricular function curve using EDVI vs. stroke work index, and the ventricular function curve response to volume infusion), this study provides evidence (P < 0.01) that septic shock produces a profound, but reversible, decrease in systolic ventricular performance.This decreased performance was not seen in controls and was associated with ventricular dilatation (P < 0.01); the latter response was dependent on an adequate volume infusion.Further studies of EDVI and pulmonary cap- illary wedge pressure during diastole revealed a significant, though reversible, shift (P < 0.001) in the diastolic volume/ pressure (or compliance) relationship during septic shock.Portions of this work were presented at the National Meeting of the American Federation for Clinical Research, Washington, DC (1985).The opinions and assertions contained in this article are the private ones of the authors, are not to be construed as official, or reflecting the views of the Armed Forces of the United States of America.The exper- iments reported herein were conducted according to the principles set forth in the "Guide for the Care and Use ofLaboratory Animals," Institute