The Comparison of Myocardial Dysfunction in Three Forms of Experimental Septic Shock

A rabbit model of septic shock was used to determine if 1) myocardial dysfunction is a common com- ponent of shock due to diverse neonatal pathogens, and 2) prostaglandins modulate septic myocardial dysfunction. The infusion of heat-killed Escherichia coli (group I), Haemophilus influenzae (group 11), or Staphylococcus ep- idermidis (group 111) produced significant decreases in the first derivative of left ventricular pressure with respect to time (p < 0.05). Each organism also produced significant changes in mean arterial pressure, cardiac output, and heart rate, while pulmonary artery pressure was altered in groups I and 111. Saline-infused control animals (group IV) exhibited no significant changes in any hemodynamic var- iable. Blood gas variables were not significantly changed in any group. These cardiovascular changes appeared de- pendent on arachidonic acid metabolism since indometha- cin pretreatment prevented the cardiovascular changes in- duced by bacterial infusion. These results suggest that septic myocardial dysfunction is a common component of gram-negative and gram-positive septic shock, and that myocardial dysfunction is modulated by prostaglandin products. (Pediatr Res 20: 1240-1242, 1986)