Sepsis and Septic Shock

Abstract

Sepsis is a clinical syndrome affecting about 19 million people all over the world and with a death rate of about 10% among ICU patients. Systemic inflammatory response syndrome (SIRS) is the first step of the clinical cascade, followed by sepsis that is SIRS plus infection, severe sepsis that is sepsis plus acute organ dysfunction, while septic shock is a state of sepsis plus circulatory failure. The lungs and the cardiovascular system are almost always involved, followed by the kidney, the gut, the brain, and the endocrine system. Gram-negative and positive bacteria are responsible for about 75–80% cases of sepsis, while fungi are the etiologic factors in a far lower percentage of cases. Interaction between parts of bacterial cell wall and receptors on host cells of the innate immune system triggers the inflammatory cascade through intracellular transcription factors and signaling pathways, leading to the activation of immune response genes and generation of circulating cytokines. Uncontrolled activation and dysregulation of inflammatory cascade and coagulation system are the main pathogenetic mechanisms of sepsis. Initial management is based on early recognition, respiratory and circulatory resuscitation, and antibiotic treatment. Subsequent patient management is based on revision of initial antimicrobial therapy, vital organ support, tight glycemic control, adequate nutritional support, and prevention of complications and organ failure. It is important to approach the patient with strict diagnostic and therapeutic protocols: the so-called “bundles of care,” a group of evidence-based measures that carried out together and within a limited timeframe are far more effective than the same interventions performed individually and without a tight time constraint.