title: Time course of iron metabolism in critically ill patients.
abstract: BACKGROUND
  Altered iron metabolism plays a central role in the development of anaemia in critically ill patients but the time course of iron status in septic and non-septic critically ill patients has not been well defined.
  
  
  METHODS
  Prospective study in a 34-bed medico-surgical ICU. The complete blood count, iron, ferritin, transferrin, and transferrin receptor concentrations, transferrin saturation and C-reactive protein (CRP) concentrations were measured on days 1, 3 and 5 of the ICU stay in 95 consecutive ICU patients (33 with sepsis and 62 without).
  
  
  RESULTS
  Despite an identical complete blood count on day 1, septic patients had significantly lower iron concentrations (21 [13-34] vs 50[28-75] microg/dL, p<0.001), transferrin concentrations (169[121-215] vs 214[173-247] mg/dL; p=0.003), and transferrin saturation (11[7-15] vs 19[11-25]%; p= 0.004), and higher ferritin concentrations (432[184-773] vs 204[78-354] ng/mL; p=0.002) than non-septic patients. These alterations were associated with a lower reticulocyte count (42[29-61] vs 58[48-77] x 10(3)/mm3; p=0.028). On day 1, CRP concentrations, which were higher in septic than in non-septic patients (20.0[13.5-27.5] vs 2.3[0.7-5.9] mg/dL; p<0.001), were directly correlated with ferritin concentrations (rho=0.55, p<0.001) and inversely correlated with transferrin concentrations (rho=-0.49, p=0.0001) and transferrin saturation (rho=-0.49, p=0.0001). After 3 days, iron and transferrin concentrations were identical in septic and non-septic patients. Iron metabolism remained altered in both populations until the 5th day.
  
  
  CONCLUSIONS
  Iron status is rapidly altered in critically ill patients, especially in septic patients. These alterations persist during the course of the disease and are associated with decreased erythropoiesis.
authors.affiliation: Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Piagnerelli
authors.forename: F
authors.initials: F
authors.lastname: Cotton
authors.forename: A
authors.initials: A
authors.lastname: Herpain
authors.forename: A
authors.initials: A
authors.lastname: Rapotec
authors.forename: R
authors.initials: R
authors.lastname: Chatti
authors.forename: B
authors.initials: B
authors.lastname: Gulbis
authors.forename: J-L
authors.initials: JL
authors.lastname: Vincent
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001772:Blood Cell Count; D002097:C-Reactive Protein / Q000378:metabolism; D016638:Critical Illness; D004906:Erythrocyte Count; D004920:Erythropoiesis; D005260:Female; D005293:Ferritins / Q000097:blood*; D006801:Humans; D007362:Intensive Care Units; D007501:Iron / Q000097:blood* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011990:Receptors, Transferrin / Q000097:blood*; D017701:Reticulocyte Count; D018805:Sepsis / Q000097:blood / Q000150:complications; D013997:Time Factors; D014168:Transferrin / Q000378:metabolism*
chemical_list: D011990:Receptors, Transferrin; D014168:Transferrin; D002097:C-Reactive Protein; D005293:Ferritins; D007501:Iron