Sepsis is a common cause for morbidity and mortality in critically ill patients. In USA, the incidence of sepsis is about 3/1000 population. However, the incidence of sepsis varies among different clinic trails. In addition, clinician empirical select antibiotic according to the epidemiology of sepsis, however, the etiology of sepsis is various in different studies. In China, the MDRO is much higher than western country. There is no study about the epidemiology of sepsis in China. Therefore, it is necessary to conduct a study about it in China.

Sepsis,especially severe sepsis is a major cause of admission to the intensive care unit (ICU) and death. In USA, the incidence of sepsis is about 3/1000 population. However, the incidence of sepsis varies among different clinic trails. Between 6 and 54% of patients admitted to ICUs have severe sepsis and the mortality rate for these patients varies from 20 to 60%. There is no exactly results of incidence of sepsis in China.

In addition, clinician empirical select antibiotic according to the epidemiology of sepsis, however, the etiology of sepsis is various in different studies. In EPIC II study, the organisms of sepsis include Gram-positive microorganisms (69.8%),Gram-negative microorganisms(62.2%) and fungi (17%). In China, the MDRO is much higher than western country. In contrast to EPIC II study, one study in China showed that the organisms of sepsis include Gram-positive microorganisms (14.5%),Gram-negative microorganisms(62.5%) and fungi (2.2%). Therefore, it is necessary to conduct a study about epidemiology of sepsis in China.

Inclusion Criteria:

sepsis patients who admitted into ICU during research period (include patients with sepsis at ICU admission and patients who has new sepsis during ICU period)

Exclusion Criteria:

The patients with second sepsis in ICU

Sepsis patient who admitted into ICU