Epidemiology of sepsis and infection in ICU patients from an international multicentre cohort study

Objectives: To examine the incidence of infections and to describe them and their outcome in intensive care unit (ICU) patients. Design and setting: International prospective cohort study in which all patients admitted to the 28 participating units in eight countries between May 1997 and May 1998 were followed until hospital discharge. Patients: A total of 14,364 patients were admitted to the ICUs, 6011 of whom stayed less than 24 h and 8353 more than 24 h. Results: Overall 3034 infectious episodes were recorded at ICU admission (crude incidence: 21.1%). In ICU patients hospitalised longer than 24 h there were 1581 infectious episodes (crude incidence: 18.9%) including 713 (45%) in patients already infected at ICU admission. These rates varied between ICUs. Respiratory, digestive, urinary tracts, and primary bloodstream infections represented about 80% of all sites. Hospital-acquired and ICU-acquired infections were documented more frequently microbiologically than community-acquired infections (71% and 86%, respectively vs. 55%). About 28% of infections were associated with sepsis, 24% with severe sepsis and 30% with septic shock, and 18% were not classified. Crude hospital mortality rates ranged from 16.9% in non-infected patients to 53.6% in patients with hospital-acquired infections at the time of ICU admission and acquiring infection during the ICU stay. Conclusions: The crude incidence of ICU infections remains high, although the rate varies between ICUs and patient subsets, illustrating the added burden of nosocomial infections in the use of ICU resources.