title: In critically ill patients, B-type natriuretic peptide (BNP) and N-terminal pro-BNP levels correlate with C-reactive protein values and leukocyte counts.
abstract: BACKGROUND
  B-type natriuretic peptide (BNP) and its N-terminal portion (NT-pro-BNP) are used for the assessment of cardiac dysfunction in patients with heart failure. However, it remains controversial whether or not this option is still valid in critically ill patients because of a possible interaction between the systemic inflammatory response and the natriuretic peptide levels. The aim of this study was to assess the relationship between natriuretic peptic levels, laboratory parameters of systemic inflammation, and pulmonary artery occlusion pressure (PAOP) in critically patients.
  
  
  METHODS
  Twelve haemodyamic unstable patients, all monitored with a pulmonary artery catheter, were included in this study. Subgroups were compared using measurement values on ICU admission. Within patient associations between different variables were evaluated by a repeated measurement ancova.
  
  
  RESULTS
  Acute heart failure and septic shock were diagnosed in 6 patients each. Despite significant differences in cardiac index and troponin T plasma level, BNP and NT-pro-BNP levels did not differ significantly between the two groups. Within patient, changes in BNP and NT-pro-BNP levels correlated significantly (p<0.01) with those in C-reactive protein values and those in leukocyte counts, but did not follow changes in PAOP.
  
  
  CONCLUSIONS
  Our results add further evidence to the hypothesis that there is an interaction between the systemic inflammatory response and the natriuretic peptides. Thus, BNP and NT-pro-BNP levels should only be used cautiously as surrogates of cardiac filling and function in haemodynamic unstable critically ill patients.
authors.affiliation: Wolfson Institute of Biomedical Research, University College London, The Cruciform Building, Gower Street, London WC1E 6BT, UK. a.rudiger@ucl.ac.uk
authors.forename: Alain
authors.initials: A
authors.lastname: Rudiger
authors.forename: Manuel
authors.initials: M
authors.lastname: Fischler
authors.forename: Paul
authors.initials: P
authors.lastname: Harpes
authors.forename: Stephan
authors.initials: S
authors.lastname: Gasser
authors.forename: Thorsten
authors.initials: T
authors.lastname: Hornemann
authors.forename: Arnold
authors.initials: A
authors.lastname: von Eckardstein
authors.forename: Marco
authors.initials: M
authors.lastname: Maggiorini
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism*; D016638:Critical Illness; D005260:Female; D006333:Heart Failure / Q000097:blood / Q000175:diagnosis; D006801:Humans; D007958:Leukocyte Count / Q000639:trends; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D012772:Shock, Septic / Q000097:blood / Q000175:diagnosis
chemical_list: D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D002097:C-Reactive Protein