title: Procalcitonin increase in early identification of critically ill patients at high risk of mortality.
abstract: OBJECTIVE
  To investigate day-by-day changes in procalcitonin and maximum obtained levels as predictors of mortality in critically ill patients.
  
  
  METHODS
  Prospective observational cohort study.
  
  
  METHODS
  : Multidisciplinary intensive care unit at Rigshospitalet, Copenhagen University Hospital, a tertiary reference hospital in Denmark.
  
  
  METHODS
  Four hundred seventy-two patients with diverse comorbidity and age admitted to this intensive care unit.
  
  
  METHODS
  Equal in all patient groups: antimicrobial treatment adjusted according to the procalcitonin level.
  
  
  RESULTS
  Daily procalcitonin measurements were carried out during the study period as well as measurements of white blood cell count and C-reactive protein and registration of comorbidity. The primary end point was all-cause mortality in a 90-day follow-up period. Secondary end points were mortality during the stay in the intensive care unit and in a 30-day follow-up period. A total of 3,642 procalcitonin measurements were evaluated in 472 critically ill patients. We found that a high maximum procalcitonin level and a procalcitonin increase for 1 day were independent predictors of 90-day all-cause mortality in the multivariate Cox regression analysis model. C-reactive protein and leukocyte increases did not show these qualities. The adjusted hazard ratio for procalcitonin increase for 1 day was 1.8 (95% confidence interval 1.3-2.7). The relative risk for mortality in the intensive care unit for patients with an increasing procalcitonin was as follows: after 1 day increase, 1.8 (95% confidence interval 1.4-2.4); after 2 days increase, 2.2 (95% confidence interval 1.6-3.0); and after 3 days increase: 2.8 (95% confidence interval 2.0-3.8).
  
  
  CONCLUSIONS
  A high maximum procalcitonin level and a procalcitonin increase for 1 day are early independent predictors of all-cause mortality in a 90-day follow-up period after intensive care unit admission. Mortality risk increases for every day that procalcitonin increases. Levels or increases of C-reactive protein and white blood cell count do not seem to predict mortality.
authors.affiliation: Department of Clinical Microbiology, Rigshospitalet, Copenhagen University Hospital, Denmark. koordinator@pass-studiet.dk
authors.forename: Jens Ulrik
authors.initials: JU
authors.lastname: Jensen
authors.forename: Lars
authors.initials: L
authors.lastname: Heslet
authors.forename: Tom Hartvig
authors.initials: TH
authors.lastname: Jensen
authors.forename: Kurt
authors.initials: K
authors.lastname: Espersen
authors.forename: Peter
authors.initials: P
authors.lastname: Steffensen
authors.forename: Michael
authors.initials: M
authors.lastname: Tvede
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000378:metabolism; D002097:C-Reactive Protein / Q000378:metabolism; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D002648:Child; D002675:Child, Preschool; D016638:Critical Illness / Q000401:mortality; D003718:Denmark / Q000453:epidemiology; D005260:Female; D006801:Humans; D007223:Infant; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D009102:Multiple Organ Failure / Q000401:mortality / Q000517:prevention & control*; D015999:Multivariate Analysis; D011379:Prognosis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood*; D012680:Sensitivity and Specificity; D018805:Sepsis / Q000401:mortality / Q000517:prevention & control*; D016019:Survival Analysis
chemical_list: D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D002097:C-Reactive Protein; D015740:Calcitonin Gene-Related Peptide