SEPSIS AND INFECTION IN THE INTENSIVE-CARE UNIT - ARE THEY RELATED

Sepsis is a clinical syndrome characterized by fever, leukocytosis or leukopenia, tachycardia, increased cardiac index, reduced systemic vas cular resistance, and hypercatabolism. It is generally believed to be a response to invasive infections, although an infectious source canno t always be identified in patients with sepsis. Over an 18-month perio d 287 patients were admitted for more than 48 hours to a noncardiac ad ult surgical intensive care unit. Data were collected concurrently and recorded in a computer database. Seventy-three patients (25%) develop ed sepsis, and 50 (68% of those with sepsis) had bacteremia, with a me an of 1.5 organisms and 3.5 positive blood cultures per patient. Only 22 of 50 patients with bacteremia had a potential infectious source, a nd there was a concordance of cultures from the putative source and th e blood stream in only 10 patients. Forty-one patients with sepsis (56 %) had no apparent infectious source, but 28 of these (68%) had bacter emia, often with multiple organisms. Forty of the 73 patients with sep sis died in the hospital. Mortality in sepsis could not be predicted b y the presence of an infectious source (P > 0.35) and was not related to bacteremia (P > 0.75). Mortality was strongly associated with the d evelopment of multiple organ failure (P < 0.0001). Sepsis is a generic response to a number of physiologic insults and does not require infe ction for expression. This inflammatory response may have survival val ue by increasing oxygen delivery to sites of injury, but uncontrolled inflammation may cause dysfunction in several vital organ systems. The associated immunosuppression results in bacterial colonization of sit es from which bacteria ordinarily are excluded. These colonizations ar e not invasive infections, they are not necessarily the cause of sepsi s, and they do not affect the outcome of patients with sepsis.