Eosinopenia and post-hospital outcomes in critically ill non-cardiac vascular surgery patients

Abstract

Background and aims: Eosinopenia is a marker for acute inflammation. We hypothesized that eosinopenia at Intensive Care Unit (ICU) admission in vascular surgery patients who receive critical care, would be associated with increased mortality following hospital discharge.

Methods and results: We performed a two-center observational cohort study of critically ill, non-cardiac adult vascular surgery patients who received treatment in Boston between 1997 and 2012 and survived hospital admission. The consecutive sample included 5083 patients (male 57%, white 82%, mean age [SD] 61.6 [17.4] years). The exposure was Absolute eosinophil count measured within 24 h of admission to the ICU and categorized as ≤10 cells/μL, 11-50 cells/μL, 51-100 cells/μL, 101-350 cells/μL (normal range), and >350 cells/μL. The primary outcome was all-cause mortality within 90 days of hospital discharge. The secondary outcome was discharge to home following hospitalization. 90-day post-discharge mortality was 6.7%, and 12.9% of patients were readmitted within 30 days. After multivariable adjustment, patients with eosinopenia (≤10 cells/μL) have a 90-day post-discharge mortality OR of 1.97 (95%CI 1.42, 2.73; P < 0.001) relative to patients with an absolute eosinophil count of 101-350 cells/μL. Further, after multivariable adjustment, patients with eosinopenia (≤10 cells/μL) have a 25% lower odds of discharge to home compared to patients with an absolute eosinophil count of 101-350 cells/μL [OR = 0.71 (CI 95% 0.59-0.85); P < 0.001].

Conclusion: Eosinopenia at ICU admission is a robust predictor of increased mortality and lower likelihood of discharge to home in vascular surgery patients treated with critical care who survive hospitalization.

Keywords: Critical illness; Eosinopenia; Mortality; Readmission; Vascular surgery.