Severe sepsis

ABSTRACT

Infection has become a common cause of morbidity and mortality in intensive care. The syndromes seen have recently been defined by the American College of Chest Physicians to clarify the nomenclature used and potentially to unify research projects. Sepsis is predisposed to by a number of co-existing pathologies and these will influence prognosis, as will any pre-morbid condition. In addition, the infecting agent involved will influence outcome. Sepsis may produce multi-organ dysfunction via alterations in the endothelium with widespread vasodilatation and altered permeability. These changes are mediated via a large array of mediators produced either directly by the infecting agent or indirectly from their action on host cells. Clinical changes include widespread vasodilatation with myocardial dysfunction, adult respiratory distress syndrome, reduced gastrointestinal perfusion with bacterial translocation across the gut wall and impaired renal, liver and endocrine function. The management of patients with sepsis syndrome includes control of the triggering infection both with antibiotics and surgical drainage of infected sites. General supportive therapy is aimed at ensuring adequate oxygen delivery by providing intraventricular filling and augmentation of cardiac output with inotropes and vasoactive drugs. Mechanical ventilation may be required for respiratory support, continuous dialysis for renal failure and nutritional support. The measurement of intraluminal pH, use of pulmonary artery catheters and goal-directed therapy are recent issues that have been discussed. Together with innovative treatments, including the use of specific antibodies to mediators, these provide new approaches to sepsis which are currently being evaluated. In this arena of new therapy the importance of preventing sepsis should be emphasized