title: Eosinophil count at intensive care unit admission was not predictor of hospital mortality: results of a case control study.
abstract: BACKGROUND
  Predicting mortality in the intensive care unit (ICU) is one of the biggest challenges in critical care medicine. Several studies have linked the presence of eosinopenia with adverse outcomes in different populations.
  
  
  METHODS
  We performed a case control study to determine whether the eosinophil count at ICU admission was a predictor of hospital mortality. We included data from patients 18 years or older admitted to the medical or surgical ICU in a university hospital in northern of Mexico. Medical records of 86 non-survivors (cases) and 99 discharged alive patients (controls) were randomly reviewed; clinical records of patients with an ICU stay of less than 24 h and those whose information was incomplete were excluded.
  
  
  RESULTS
  Median of eosinophil count at ICU admission was 0.013 (interquartile range (IQR) 0.00 to 0.57) K/μL. There was no significant statistical difference in eosinophils at admission between survivors and non-survivors (0.014 [IQR 0.00 to 0.36] vs. 0.010 [IQR 0.00 to 0.57] K/μL, P = 0.35). In the multivariate analysis, APACHE II score at ICU admission and discharge were the only mortality predictors. Survivors had a significantly greater increase in eosinophil count during the first 7 days of ICU stay (0.104 [IQR -0.64 to 0.41] vs. 0.005 [IQR -1.79 to 0.43] K/μL, P = 0.004).
  
  
  CONCLUSIONS
  In our study, eosinophil count at ICU admission was not associated with increased hospital mortality. The larger increase in number of eosinophils observed during the first week of ICU stay in surviving patients deserves to be investigated further.
authors.affiliation: Department of Internal Medicine, "Dr. José E. González" University Hospital, Nuevo León Autonomous University, Av. Francisco I. Madero1500, Suburb: Mitras Centro, Monterrey, NL 64460 Mexico.
authors.forename: Emmanuel Jesús
authors.initials: EJ
authors.lastname: Escobar-Valdivia
authors.affiliation: Department of Pulmonary and Critical Care Medicine, "Dr. José E. González" University Hospital, Nuevo León Autonomous University, Av. Francisco I. Madero1500, Suburb: Mitras Centro, Monterrey, NL 64460 Mexico.
authors.forename: Julio Edgardo
authors.initials: JE
authors.lastname: González-Aguirre
authors.affiliation: Department of Internal Medicine, "Dr. José E. González" University Hospital, Nuevo León Autonomous University, Av. Francisco I. Madero1500, Suburb: Mitras Centro, Monterrey, NL 64460 Mexico.
authors.forename: Eunice Rebeca
authors.initials: ER
authors.lastname: Carrillo-Cisneros
authors.affiliation: Department of Internal Medicine, "Dr. José E. González" University Hospital, Nuevo León Autonomous University, Av. Francisco I. Madero1500, Suburb: Mitras Centro, Monterrey, NL 64460 Mexico.
authors.forename: Karla Carolina
authors.initials: KC
authors.lastname: Guerra-Leza
authors.affiliation: Department of Pulmonary and Critical Care Medicine, "Dr. José E. González" University Hospital, Nuevo León Autonomous University, Av. Francisco I. Madero1500, Suburb: Mitras Centro, Monterrey, NL 64460 Mexico.
authors.forename: Roberto
authors.initials: R
authors.lastname: Mercado-Longoría
keywords: Critical care; Eosinophils; Hospital mortality