title: Half-lives of albumin and cholinesterase in critically ill patients.
abstract: BACKGROUND
  Albumin and plasma cholinesterase are markedly reduced in critical illness. However, the plasma half-lives of these two proteins have only been determined in very limited numbers of patients mostly outside intensive care. Therefore, we determined the kinetics of decrease of albumin and cholinesterase in a large population of critically ill patients.
  
  
  METHODS
  Medical records of all patients of two university-affiliated surgical intensive care units during a time period of 8 years were retrospectively evaluated. To calculate the rate of fall, the first value in every episode of decreasing albumin or cholinesterase was arbitrarily set at 100% and the ensuing lower values were expressed as the respective fractions.
  
  
  RESULTS
  Records of 3591 patients were evaluated. Regression analysis exhibited an exponential evolution of albumin and cholinesterase over time with corresponding mean apparent plasma half-lives of 11.8 days [95% confidence interval (CI): 10.8-12.9] for albumin and 7.8 days (95% CI: 7.4-8.3) for cholinesterase.
  
  
  CONCLUSIONS
  These findings suggest that the apparent plasma half-lives of albumin and cholinesterase in critically ill surgical patients are considerably shorter than previously determined.
authors.affiliation: Department of Anaesthesiology, General Intensive Care and Pain Control, Medical University of Vienna, Vienna, Austria. thomas.gamsjaeger@meduniwien.ac.at
authors.forename: Thomas
authors.initials: T
authors.lastname: Gamsjäger
authors.forename: Lydia
authors.initials: L
authors.lastname: Brenner
authors.forename: Christian
authors.initials: C
authors.lastname: Sitzwohl
authors.forename: Christian
authors.initials: C
authors.lastname: Weinstabl
mesh_terms: D000418:Albumins / Q000032:analysis / Q000378:metabolism*; D015415:Biomarkers / Q000097:blood / Q000378:metabolism; D002802:Cholinesterases / Q000097:blood* / Q000378:metabolism*; D016638:Critical Illness; D006207:Half-Life; D006801:Humans; D007362:Intensive Care Units; D012044:Regression Analysis; D013997:Time Factors
chemical_list: D000418:Albumins; D015415:Biomarkers; D002802:Cholinesterases