title: Assessment of plasma and red cell trace element concentrations, disease severity, and outcome in patients with critical illness.
abstract: OBJECTIVE
  The purpose of the study is to examine the value of both plasma and red cell trace element measurements when assessing nutritional status in patients with critical illness.
  
  
  METHODS
  A total of 125 patients who were admitted to intensive care unit with evidence of systemic inflammatory response as per Bone's criteria were recruited. Venous blood samples were obtained from all on admission and, in 31 of the 125 patients, on approximately days 4 and 7. Copper, zinc, and selenium concentrations were measured in plasma and erythrocytes and results related to mortality and patient outcome measures.
  
  
  RESULTS
  A total of 125 critically ill patients were recruited; 81 (66%) were male, the median age was 60 (range, 18-100), and the medical/surgical proportion was 55/70 (44%/56%). The median (lower and upper 2.5th percentile) Acute Physiology and Chronic Health Evaluation II score, Sequential Organ Failure Assessment score, and length of stay and mortality were 21 (16-26), 7 (4-9) 3.7 days (1.5-11.1) and 19%, respectively. Plasma zinc and selenium concentrations were significantly lower on admission compared with reference intervals, whereas copper was increased. Normal plasma glutathione peroxidase activity suggested selenium status was adequate on admission; erythrocyte concentrations of glutathione peroxidase and trace elements were normal, suggesting adequate nutritional status 1 to 2 months before admission. Only plasma zinc and selenium were inversely associated with C-reactive protein (rs = -0.266, P = .004, rs = -0.322, P < .001, respectively). Compared with survivors, albumin (P < .001) concentrations were significantly lower in the nonsurvivor group. No significant difference of plasma selenium and zinc between survivors and nonsurvivors was found, although plasma selenium concentrations tended to be lower (P = .04). On multivariate logistic regression analysis of the significant variables, none was independently associated with mortality.
  
  
  CONCLUSIONS
  The altered plasma concentrations of zinc, selenium, and copper in patients with critical illness were primarily due to the effects of the systemic inflammatory response and do not reliably indicate their status.
authors.affiliation: The Scottish Trace Element and Micronutrient Reference Laboratory, Department of Biochemistry, Royal Infirmary, Glasgow G31 2ER, UK.
authors.forename: Fiona
authors.initials: F
authors.lastname: Stefanowicz
authors.affiliation: Academic Unit of Anaesthesia, College of Medical, Veterinary and Life of Sciences-University of Glasgow, Royal Infirmary, Glasgow G31 2ER, UK.
authors.forename: Rawia A
authors.initials: RA
authors.lastname: Gashut
authors.affiliation: The Scottish Trace Element and Micronutrient Reference Laboratory, Department of Biochemistry, Royal Infirmary, Glasgow G31 2ER, UK.
authors.forename: Dinesh
authors.initials: D
authors.lastname: Talwar
authors.affiliation: The Scottish Trace Element and Micronutrient Reference Laboratory, Department of Biochemistry, Royal Infirmary, Glasgow G31 2ER, UK. Electronic address: Andrew.duncan@ggc.scot.nhs.uk.
authors.forename: Andrew
authors.initials: A
authors.lastname: Duncan
authors.affiliation: Academic Unit of Surgery, College of Medical, Veterinary and Life of Sciences- University of Glasgow, Royal Infirmary, Glasgow G31 2ER, UK.
authors.forename: Julia F
authors.initials: JF
authors.lastname: Beulshausen
authors.affiliation: Academic Unit of Anaesthesia, College of Medical, Veterinary and Life of Sciences-University of Glasgow, Royal Infirmary, Glasgow G31 2ER, UK.
authors.forename: Donald C
authors.initials: DC
authors.lastname: McMillan
authors.affiliation: Academic Unit of Surgery, College of Medical, Veterinary and Life of Sciences- University of Glasgow, Royal Infirmary, Glasgow G31 2ER, UK.
authors.forename: John
authors.initials: J
authors.lastname: Kinsella
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000418:Albumins / Q000032:analysis; D002097:C-Reactive Protein / Q000032:analysis; D003300:Copper / Q000097:blood*; D016638:Critical Illness / Q000401:mortality*; D004912:Erythrocytes / Q000737:chemistry*; D005260:Female; D005979:Glutathione Peroxidase / Q000097:blood; D006801:Humans; D007362:Intensive Care Units; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009752:Nutritional Status; D063305:Organ Dysfunction Scores; D012643:Selenium / Q000097:blood*; D012720:Severity of Illness Index; D014131:Trace Elements / Q000097:blood*; D055815:Young Adult; D015032:Zinc / Q000097:blood*
chemical_list: D000418:Albumins; D014131:Trace Elements; D003300:Copper; D002097:C-Reactive Protein; D005979:Glutathione Peroxidase; D012643:Selenium; D015032:Zinc
keywords: Copper; Critical illness; Selenium; Systemic inflammatory response; Zinc