Eosinopenia is a reliable marker of sepsis on admission to medical intensive care units

TLDR

Eosinopenia is a cheap and forgotten marker of acute infection that has not been evaluated previously in intensive care units. The study aimed to test the value of eosinopenia for diagnosing sepsis in patients admitted to medical ICUs. A prospective cohort of 177 adult ICU admissions had eosinophil counts measured on admission, and blinded intensivists classified patients into noninfected, SIRS, sepsis, severe sepsis, or septic shock. Eosinopenia distinguished infected from noninfected ICU patients with an AUC of 0.89 (sensitivity 80 %, specificity 91 % at < 50 cells/mm³) and discriminated SIRS from infection with an AUC of 0.84 (sensitivity 80 %, specificity 80 % at < 40 cells/mm³), indicating it is a strong marker for infection but only moderate for SIRS, suggesting clinical utility in ICU practice.

Abstract

Eosinopenia is a cheap and forgotten marker of acute infection that has not been evaluated previously in intensive care units (ICUs). The aim of the present study was to test the value of eosinopenia in the diagnosis of sepsis in patients admitted to ICUs.A prospective study of consecutive adult patients admitted to a 12-bed medical ICU was performed. Eosinophils were measured at ICU admission. Two intensivists blinded to the eosinophils classified patients as negative or with systemic inflammatory response syndrome (SIRS), sepsis, severe sepsis, or septic shock.A total of 177 patients were enrolled. In discriminating noninfected (negative + SIRS) and infected (sepsis + severe sepsis + septic shock) groups, the area under the receiver operating characteristic curve was 0.89 (95% confidence interval (CI), 0.83 to 0.94). Eosinophils at <50 cells/mm3 yielded a sensitivity of 80% (95% CI, 71% to 86%), a specificity of 91% (95% CI, 79% to 96%), a positive likelihood ratio of 9.12 (95% CI, 3.9 to 21), and a negative likelihood ratio of 0.21(95% CI, 0.15 to 0.31). In discriminating SIRS and infected groups, the area under the receiver operating characteristic curve was 0.84 (95% CI, 0.74 to 0.94). Eosinophils at <40 cells/mm3 yielded a sensitivity of 80% (95% CI, 71% to 86%), a specificity of 80% (95% CI, 55% to 93%), a positive likelihood ratio of 4 (95% CI, 1.65 to 9.65), and a negative likelihood ratio of 0.25 (95% CI, 0.17 to 0.36).Eosinopenia is a good diagnostic marker in distinguishing between noninfection and infection, but is a moderate marker in discriminating between SIRS and infection in newly admitted critically ill patients. Eosinopenia may become a helpful clinical tool in ICU practices.