B-type natriuretic peptide (BNP) and N-terminal-proBNP for heart failure diagnosis in shock or acute respiratory distress.
BACKGROUND
Plasma B-type natriuretic peptide (BNP) assay is recommended as a diagnostic tool in emergency-room patients with acute dyspnea. In the intensive care unit (ICU), the utility of this peptide remains a matter of debate. The objectives of this study were to determine whether cut-off values for BNP and N-terminal-proBNP (NT-proBNP) reliably diagnosed right and/or left ventricular failure in patients with shock or acute respiratory distress, and whether non-cardiac factors led to an increase in these markers.


METHODS
Plasma BNP and NT-proBNP levels and echocardiographic parameters of cardiac dysfunction were determined in 41 patients within 24 h of the onset of shock or acute respiratory distress.


RESULTS
BNP and NT-proBNP levels were higher in the 25 patients with heart failure than in the other 16 patients: 491.7 +/- 418 pg/ml vs. 144.3 +/- 128 pg/ml and 2874.4 +/- 2929 pg/ml vs. 762.7 +/- 1128 pg/ml, respectively (P < 0.05). In the diagnosis of cardiac dysfunction, BNP > 221 pg/ml and NT-proBNP > 443 pg/ml had 68% and 84% sensitivity, respectively, and 88% and 75% specificity, respectively, but there was a substantial overlap of BNP and NT-proBNP values between patients with and without heart failure. BNP and NT-proBNP were elevated, but not significantly, in patients with isolated right ventricular dysfunction. Patients with renal dysfunction and normal heart function had significantly higher levels of BNP (258.6 +/- 144 pg/ml vs. 92.4 +/- 84 pg/ml) and NT-proBNP (2049 +/- 1320 pg/ml vs. 118 +/- 104 pg/ml) than patients without renal dysfunction.


CONCLUSIONS
Both BNP and NT-proBNP can help in the diagnosis of cardiac dysfunction in ICU patients, but cannot replace echocardiography. An elevated BNP or NT-proBNP level merely indicates the presence of a 'cardiorenal distress' and should prompt further investigation.
Bal
L
L
General Intensive Care Unit, Sud Francilien Hospital Center, Evry, France.
Thierry
S
S
Brocas
E
E
Van de Louw
A
A
Pottecher
J
J
Hours
S
S
Moreau
M H
MH
Perrin Gachadoat
D
D
Tenaillon
A
A
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007668:Kidney / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010446:Peptide Fragments / Q000097:blood*; D012128:Respiratory Distress Syndrome / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D012769:Shock / Q000097:blood / Q000150:complications* / Q000503:physiopathology; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis*; D018497:Ventricular Dysfunction, Right / Q000175:diagnosis*
D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain