Epidemiology, clinical presentation, and outcomes of 620 patients with eosinophilia in the intensive care unit.

PURPOSE: Although eosinophil-induced manifestations can be life-threatening, studies focusing on the epidemiology and clinical manifestations of eosinophilia in the intensive care unit (ICU) are lacking. METHODS: A retrospective, national, multicenter (14 centers) cohort study over 6 years of adult patients who presented with eosinophilia ≥ 1 × 109/L on two blood samples performed from the day before admission to the last day of an ICU stay. RESULTS: 620 patients (0.9% of all ICU hospitalizations) were included: 40% with early eosinophilia (within the first 24 h of ICU admission, ICU-Eo1 group) and 56% with delayed (> 24 h after ICU admission, ICU-Eo2 group) eosinophilia. In ICU-Eo1, eosinophilia was mostly due to respiratory (14.9%) and hematological (25.8%) conditions, frequently symptomatic (58.1%, mainly respiratory and cardiovascular manifestations) requiring systemic corticosteroids in 32.2% of cases. In ICU-Eo2, eosinophil-related organ involvement was rare (25%), and eosinophilia was mostly drug-induced (46.8%). Survival rates at day 60 (D60) after ICU admission were 21.4% and 17.2% (p = 0.219) in ICU-Eo1 and ICU-Eo2 patients, respectively. For ICU-Eo1 patients, in multivariate analysis, risk factors for death at D60 were current immunosuppressant therapy at ICU admission, eosinophilia of onco-hematological origin and the use of vasopressors at ICU admission, whereas older age and the use of vasopressors or mechanical ventilation at the onset of eosinophilia were associated with a poorer prognosis for ICU-Eo2 patients. CONCLUSION: Eosinophilia ≥ 1 × 109/L is not uncommon in the ICU. According to the timing of eosinophilia, two subsets of patients requiring different etiological workups and management can be distinguished.