Epidemiological differences between sepsis syndrome with bacteremia and culture-negative sepsis

OBJECTIVE: To explore the association of putative disease markers and potential risk factors with the nosocomial sepsis syndrome. DESIGN: Prospective case-control study matched for gender, age, and length of preinfection hospital stay. SETTING: 1,200-bed tertiary-care center in Spain. PATIENTS: Cases were selected using the sepsis syndrome criteria of the American College of Chest Physicians/Society of Critical Care Medicine Consensus Conference and were divided into three groups: sepsis with bacteremia (109 cases), sepsis with positive culture other than blood (122 cases), and sepsis with negative culture (115 cases without documented infection but with sepsis syndrome, clinically suspected infection, and empirical antibiotic treatment). Controls were randomly selected from the daily list of inpatients. Data were collected prospectively. Crude and multiple-risk-factor-adjusted odds ratios and their 95% confidence intervals were computed using conditional logistic regression analysis. RESULTS: Presence of coma in the 48 hours before sepsis, intensive care unit (ICU) stay, and decreased serum albumin levels at admission were common epidemiological markers identified for the three groups of cases. Having a central venous catheter was the main healthcare-related risk factor for bacteremia. ICU stay and nasogastric tube were the main risk factors for sepsis with positive culture other than blood. Coma within 48 hours before sepsis and the need of intensive care were the only two markers identified for culture-negative sepsis. CONCLUSION: Culture-negative sepsis does not behave like culture-positive sepsis, and this may imply that implementation of preventive measures to decrease the risk of bacteremia may not decrease the risk of sepsis syndrome (Infect Control Hosp Epidemiol 2000;21:639-644).