title: Protein C concentrations correlate with organ dysfunction and predict outcome independent of the presence of sepsis.
abstract: BACKGROUND
  Characterizing the evolution of protein C concentrations in critically ill patients may help in identifying high risk groups and potential therapeutic targets. The authors investigated the time courses of protein C concentrations and their relation to the presence of sepsis, organ dysfunction/failure, and outcome.
  
  
  METHODS
  This observational cohort study, in a university hospital surgical intensive care unit (ICU), included 312 consecutive patients with an estimated ICU length of stay more than 48 h. Plasma protein C concentrations and parameters of organ dysfunction were measured daily until discharge or death.
  
  
  RESULTS
  Protein C concentrations were below the lower limit of normal in 50.6% of patients (n = 158) on admission and decreased to a nadir within 3-4 days after admission before almost normalizing by 2 weeks thereafter, irrespective of the presence of sepsis, sex, source and type of admission, and type of surgery. The minimum protein C concentration was lower in patients with severe sepsis/septic shock (n = 54) than in those with sepsis (n = 63) and those who never had sepsis (n = 195), and was negatively correlated to the maximum Sequential Organ Failure Assessment score (R = 0.345, P < 0.001). Protein C levels were lower in nonsurvivors (n = 46; 14.7%) than in survivors, especially in the first 4 days after admission. In a multivariable analysis with ICU mortality as the dependent variable, a minimum protein C concentration less than 45% was an independent risk factor for ICU death.
  
  
  CONCLUSIONS
  In critically ill surgical patients, protein C concentrations were generally low, associated with organ dysfunction/failure, and independently associated with a higher risk of ICU mortality.
authors.affiliation: Department of Anesthesiology and Intensive Care, Friedrich Schiller University, Jena, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Brunkhorst
authors.forename: Yasser
authors.initials: Y
authors.lastname: Sakr
authors.forename: Stefan
authors.initials: S
authors.lastname: Hagel
authors.forename: Konrad
authors.initials: K
authors.lastname: Reinhart
mesh_terms: D018806:APACHE; D000368:Aged; D015331:Cohort Studies; D003422:Critical Care; D003625:Data Collection; D018450:Disease Progression; D005260:Female; D006801:Humans; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D009102:Multiple Organ Failure / Q000097:blood* / Q000401:mortality / Q000628:therapy*; D011237:Predictive Value of Tests; D011486:Protein C / Q000032:analysis / Q000378:metabolism*; D012372:ROC Curve; D018805:Sepsis / Q000097:blood* / Q000401:mortality / Q000628:therapy*; D012772:Shock, Septic / Q000097:blood / Q000401:mortality / Q000628:therapy
chemical_list: D011486:Protein C