It is essential that clinicians recognize these early signs and symptoms because successful management of septic shock depends on early recognition and appropriate intervention. Unfortunately, no single clinical or laboratory test is sufficiently specific and sensitive to reliably confirm the diagnosis of septic shock. Blood cultures may or may not be positive, leukocytosis or neutropenia may be seen, hyperglycemia or hypoglycemia may occur, and either respiratory alkalosis or metabolic acidosis may occur. It is the constellation of signs and symptoms that leads to a diagnosis of septic shock. The most common hemodynamic findings in early septic shock are a high cardiac output and a low systemic vascular resistance state, with initial maintenance of the systolic blood pressure as the heart attempts to compensate for the loss of systemic vascular tone.
Myocardial performance is diminished even in the early phases of septic shock.
Without adequate intervention, circulating blood volume is continually lost into the interstitial space and intracellular locations. The heart can no longer compensate sufficiently, and systolic hypotension results. Deterioration of myocardial performance accompanied by diffuse vasoconstriction marks the late refractory state of septic shock. Septic shock may be associated with a loss of normal autoregulation between oxygen delivery and oxygen consumption in the tissues. A supply-dependent dysoxia may contribute to tissue injury in multiorgan failure in sepsis.