Sepsis in European intensive care units: results of the SOAP study

OBJECTIVE: To better define the incidence of sepsis and the characteristics of critically ill patients in European intensive care units. DESIGN: Cohort, multiple-center, observational study. SETTING: One hundred and ninety-eight intensive care units in 24 European countries. PATIENTS: All new adult admissions to a participating intensive care unit between May 1 and 15, 2002. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Demographic data, comorbid diseases, and clinical and laboratory data were collected prospectively. Patients were followed up until death, until hospital discharge, or for 60 days. Of 3,147 adult patients, with a median age of 64 yrs, 1,177 (37.4%) had sepsis; 777 (24.7%) of these patients had sepsis on admission. In patients with sepsis, the lung was the most common site of infection (68%), followed by the abdomen (22%). Cultures were positive in 60% of the patients with sepsis. The most common organisms were Staphylococcus aureus (30%, including 14% methicillin-resistant), Pseudomonas species (14%), and Escherichia coli (13%). Pseudomonas species was the only microorganism independently associated with increased mortality rates. Patients with sepsis had more severe organ dysfunction, longer intensive care unit and hospital lengths of stay, and higher mortality rate than patients without sepsis. In patients with sepsis, age, positive fluid balance, septic shock, cancer, and medical admission were the important prognostic variables for intensive care unit mortality. There was considerable variation between countries, with a strong correlation between the frequency of sepsis and the intensive care unit mortality rates in each of these countries. CONCLUSIONS: This large pan-European study documents the high frequency of sepsis in critically ill patients and shows a close relationship between the proportion of patients with sepsis and the intensive care unit mortality in the various countries. In addition to age, a positive fluid balance was among the strongest prognostic factors for death. Patients with intensive care unit acquired sepsis have a worse outcome despite similar severity scores on intensive care unit admission.