The Italian SEPSIS study: preliminary results on the incidence and evolution of SIRS, sepsis, severe sepsis and septic shock.

This prospective, multicenter, epidemiological study was carried out in 99 Italian ICUs, distributed throughout the country, from April 1993 to March 1994. In the study, we applied the new ACCP/SCCM classification system for sepsis (SIRS, sepsis, severe sepsis and septic shock) and determined the prevalence, incidence, evolution and outcome of these categories in critically ill patients. The preliminary analysis of 1101 patients showed that on admission SIRS accounted for about half of the diagnoses (52%) with sepsis, severe sepsis and septic shock accounting for 4.5%, 2.1% and 3% of patients, respectively. Patients with severe sepsis or septic shock more frequently had high SAPS scores than patients without sepsis. Mortality rates were similar in patients with SIRS (26.5%) and without SIRS or infection (24%), but rose to 36% in patients with sepsis, to 52% in those with severe sepsis and to 81.8% in those with septic shock. Sepsis, severe sepsis and septic shock were more common in patients with medical diagnoses, and neither severe sepsis nor septic shock was observed in trauma patients. With respect to evolution, the incidence of septic shock was progressively higher in patients admitted with more severe "sepsis-related" diagnoses, while only a trivial difference in rates of incidence was observed between SIRS patients and those admitted without SIRS or any septic disorder (nil). The breakdown of the various ACCP/SCCM "sepsis-related" diagnoses at any time during the study was: SIRS in 58% of the population, sepsis in 16.3%, severe sepsis in 5.5% and septic shock in 6.1%. It seems reasonable to expect from the final evaluation of our study answers to the questions raised by the ACCP/SCCM Consensus Conference about the correlations between "sepsis-related" diagnosis, severity score, organ dysfunction score and outcome.