THE ROLE OF INFECTION IN OUTCOME OF MULTIPLE ORGAN FAILURE

It is widely assumed that infections are the principal cause and prima ry outcome determinant of the syndrome of Multiple Organ Failure (MOF) in critically ill patients. Infections are frequent in these patients , but the prevention and treatment of infections may not influence the course of MOE This study tested the hypothesis that infections play a decisive role in the outcome of MOF. Data were gathered concurrently on all adult patients admitted over an 18-month period to a non-cardia c surgical ICU at a university hospital and recorded in a computer dat abase. Sepsis was defined as a state characterized by at least three o f the following: fever, tachycardia, leukocytosis or leukopenia, incre ased cardiac index, reduced systemic vascular resistance, and hypercat abolism manifested by nitrogen-wasting. The presence of an infection w as not required for the diagnosis of sepsis. Mild sepsis was defined a s the presence of three or four parameters. Severe sepsis was defined as the presence of five or six parameters. MOF was defined as the deve lopment of dysfunction of at least two of the following major organ sy stems: cardiac, gut, pulmonary, renal, cerebral, and hepatic. Of 749 a dmissions, 73 patients developed MOE Thirty four (47%) had a documente d source of infection, 37 (51%) had positive blood cultures, and all h ad sepsis. Hospital mortality was 66 percent (48 of 73 patients). Deat h could not be predicted by bacteremia (P > 0.25), nor by the presence of an infectious source (P = 1.0), but was strongly associated with s evere sepsis (P < 0.0005). The mean number of organs with dysfunction was 3.8 in patients with severe sepsis and 2.4 in those with mild seps is (P < 0.001). The syndrome of MOF is associated with a high incidenc e of colonization and proliferation of bacteria in privileged sites. H owever, infections are not a necessary cause of MOF, and their presenc e does not determine outcome in this syndrome. Many of the infections that occur in patients with MOF seem to be caused by loss of host immu ne function and are, therefore, a consequence of, not a cause of, MOF. Sepsis, which is a nonbacteriologic host response to a variety of phy siologic insults (e.g., infections, trauma, inflammatory diseases, hep atic failure) is associated with progressive organ dysfunction and a g reater probability of death.