In gram-negative septicemia, early findings before shock sets in is -

Cardiac output and total peripheral resistance in septic shock The decrease in peripheral resistance is the hallmark of early (hyperdynamic) stage of septic shock, this feature distinguishes it from other types of shock, e.g., hypovolemic and cardiogenic shock. Decreased peripheral resistance leads to a compensatory increase in cardiac output thus the cardiac output is maintained or some time increased despite shock. Decreased peripheral resistance and increased CO leads to increased blood flow and total oxygen delivery to the tissues. But, still, the tissues lack O2 due to local microcirculatory changes produced as a result of sepsis which causes decrease tissue extraction of oxygen. So, increased blood flow and cardiac output are still inadequate to meet the total metabolic needs of the tissue which are increased in sepsis. As sepsis progresses, hypodynamic stage supervenes in which there is decreased Cardiac output and vasoconstriction (↑ peripheral resistance).