Hemodynamic Measurements in Bacteremia and Septic Shock in Man

Patients studied after genitourinary instrumentation have a high incidence of bacteremia. Of 31 such patients studied, eight developed gram-negative bacteremia, 10 developed gram-positive bacteremia, three developed mixed bacteremia, and 10 were abacteremic after instrumentation. Patients with gram-negative bacteremia had greater falls in central venous pressure and systemic vascular resistance and greater increases in cardiac index than either the abacteremic group or the patients with gram-positive bacteremia. These findings are consistent with vasodilatation during early gram-negative bacteremia due to release of a vasodilator substance. Fifty patients were studied during established septic shock, and the 31 with gram-negative infections had lower cardiac output and heart rates than the 19 with gram-positive infections. Vasoconstriction was more common in patients with gram-negative infections. In established shock due to gram-negative organisms, myocardial function appeared to be depressed, and vasodilatation was less marked.