The epidemiology of acute organ system dysfunction from severe sepsis outside of the intensive care unit

Background: Severe sepsis is a common, costly, and complex problem, the epidemiology of which has only been well studied in the intensive care unit (ICU). However, nearly half of all patients with severe sepsis are cared for outside the ICU.

Objective: To determine rates of infection and organ system dysfunction in patients with severe sepsis admitted to non-ICU services.

Design: Retrospective cohort study.

Setting: A large, tertiary, academic medical center in the United States.

Patients: Adult patients initially admitted to non-ICU medical services from 2009 through 2010.

Measurements: All International Classification of Diseases, 9th Revision, Clinical Modification diagnosis codes were screened for severe sepsis. Three hospitalists reviewed a sample of medical records evaluating the characteristics of severe sepsis.

Results: Of 23,288 hospitalizations, 14% screened positive for severe sepsis. A sample of 111 cases was manually reviewed, identifying 64 cases of severe sepsis. The mean age of patients with severe sepsis was 63 years, and 39% were immunosuppressed prior to presentation. The most common site of infection was the urinary tract (41%). The most common organ system dysfunctions were cardiovascular (hypotension) and renal dysfunction occurring in 66% and 64% of patients, respectively. An increase in the number of organ systems affected was associated with an increase in mortality and eventual ICU utilization. Severe sepsis was documented by the treating clinicians in 47% of cases.

Conclusions: Severe sepsis was commonly found and poorly documented on the wards at our medical center. The epidemiology and organ dysfunctions among patients with severe sepsis appear to be different from previously described ICU severe sepsis populations.