ObjectiveTo describe the incidence and causes of systemic inflammatory response syndrome (SIRS), to determine the risk factors for its development, and to assess its impact on the outcome of patients hospitalized for gastrointestinal bleeding.DesignProspective, observational study.SettingA 528-bed, university-affiliated, teaching hospital.PatientsThe study included 411 adults hospitalized for gastrointestinal bleeding from January 1, 1995, through June 30, 1996.MeasurementsWe obtained the demographic data, selected clinical findings, laboratory values, length of hospital stay, presence and cause of SIRS, presence of organ failure, and in-hospital mortality for each patient. The Acute Physiology and Chronic Health Evaluation II (APACHE II) score was calculated. Univariate and multivariate logistic regression analyses were used to determine differences between groups.ResultsPatients' ages (mean +/- SD) were 55.9 +/- 17.3 yr; 227 (55%) were male; 247 (60%) were African-American. SIRS developed in 112 patients (27%). Sepsis was the cause of SIRS in 63% of patients (70/112). Severe sepsis developed in 20 patients and septic shock in 5 patients. The most common cause of sepsis was pneumonia (19). There were no significant differences in age, gender, race, and the presence of liver disease between patients with and without SIRS. Upper gastrointestinal bleeding (76/211 vs. 36/200; p = .0196), intensive care unit admission (73/152 vs. 39/259; p < .0001), and higher APACHE II scores (median, 17 vs. 11; p < .0001) were associated with the development of SIRS. The length of hospital stay was longer (median, 9.5 vs. 3 days; p < .0001), and the number of organ failures (median, 1 vs. 0; p < .0001) and in-hospital mortality rates (23 vs. 4%; p < .0001) were higher in patients with SIRS than in those without SIRS.ConclusionsSIRS occurs in 27% of patients admitted for gastrointestinal bleeding and is associated with a poor prognosis. Intensive care unit admission, upper gastrointestinal bleeding, and high APACHE II scores are risk factors for the development of SIRS in patients hospitalized for gastrointestinal bleeding. (Crit Care Med 1999; 27:554-557)