title: Red blood cell distribution width during the first week is associated with severity and mortality in septic patients.
abstract: OBJECTIVE
  Higher values of red blood cell distribution width (RDW) have been found in non-surviving than in surviving septic patients. However, it is unknown whether RDW during the first week of sepsis evolution is associated with sepsis severity and early mortality, oxidative stress and inflammation states, and these were the aims of the study.
  
  
  METHODS
  We performed a prospective, observational, multicenter study in six Spanish Intensive Care Units with 297 severe septic patients. We measured RDW, serum levels of malondialdehyde (MDA) to assess oxidative stress, and tumour necrosis factor (TNF)-α to assess inflammation at days 1, 4, and 8. The end-point was 30-day mortality.
  
  
  RESULTS
  We found higher RDW in non-surviving (n = 104) than in surviving (n = 193) septic patients at day 1 (p = 0.001), day 4 (p = 0.001), and day 8 (p = 0.002) of ICU admission. Cox regression analyses showed that RDW at day 1 (p<0.001), 4 (p = 0.005) and 8 (p = 0.03) were associated with 30-day mortality. Receiver operating characteristic curves showed that RDW at day 1 (p<0.001), 4 (p<0.001), and 8 (p<0.001) could be used to predict 30-day mortality. RDW showed a positive correlation with serum MDA levels at day 1 and day 4, with serum TNF-α levels at days 4 and 8, and with SOFA score at days 1, 4 and 8.
  
  
  CONCLUSIONS
  The major findings of our study were that non-surviving septic patients showed persistently higher RDW during the first week of ICU stay than survivors, that RDW during the first week was associated with sepsis severity and mortality, that RDW during the first week could be used as biomarker of outcome in septic patients, and that there was an association between RDW, serum MDA levels, and serum TNF-α levels during the first week.
authors.affiliation: Intensive Care Unit, Hospital Universitario de Canarias, La Laguna, Tenerife, Spain.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Lorente
authors.affiliation: Intensive Care Unit, Hospital Universitario Nuestra Señora Candelaria, Santa Cruz de Tenerife, Tenerife, Spain.
authors.forename: María M
authors.initials: MM
authors.lastname: Martín
authors.affiliation: Deparment of Phisiology, Faculty of Medicine, University of the La Laguna, La Laguna, Tenerife, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Abreu-González
authors.affiliation: Intensive Care Unit, Hospital Universitario Dr. Negrín, Las Palmas de Gran Canaria, Gran Canria, Spain.
authors.forename: Jordi
authors.initials: J
authors.lastname: Solé-Violán
authors.affiliation: Intensive Care Unit, Hospital Clínico Universitario de Valencia, Valencia, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Ferreres
authors.affiliation: Intensive Care Unit, Hospital San Jorge, Huesca, Spain.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Labarta
authors.affiliation: Intensive Care Unit, Hospital Insular, Las Palmas de Gran Canaria, Gran Canaria, Spain.
authors.forename: César
authors.initials: C
authors.lastname: Díaz
authors.affiliation: Intensive Care Unit, Hospital Universitario de Canarias, La Laguna, Tenerife, Spain.
authors.forename: Oswaldo
authors.initials: O
authors.lastname: González
authors.affiliation: Intensive Care Unit, Hospital Universitario Nuestra Señora Candelaria, Santa Cruz de Tenerife, Tenerife, Spain.
authors.forename: Daida
authors.initials: D
authors.lastname: García
authors.affiliation: Research Unit, Hospital Universitario de Canarias, La Laguna, Tenerife, Spain.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Jiménez
authors.affiliation: Laboratory Deparment, Hospital Universitario de Canarias, La Laguna, Tenerife, Spain.
authors.forename: Juan M
authors.initials: JM
authors.lastname: Borreguero-León
mesh_terms: D000328:Adult; D000368:Aged; D004912:Erythrocytes / Q000648:ultrastructure*; D005260:Female; D006801:Humans; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D018805:Sepsis / Q000097:blood* / Q000453:epidemiology / Q000401:mortality; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D014409:Tumor Necrosis Factor-alpha; D008315:Malondialdehyde