Diagnostic and prognostic utility of brain natriuretic Peptide in subjects admitted to the ICU with hypoxic respiratory failure due to noncardiogenic and cardiogenic pulmonary edema.
BACKGROUND
Brain natriuretic peptide (BNP) is useful in diagnosing congestive heart failure (CHF) in patients presenting in the emergency department with acute dyspnea. We prospectively tested the utility of BNP for discriminating ARDS vs cardiogenic pulmonary edema (CPE).


METHODS
We enrolled ICU patients with acute hypoxemic respiratory failure and bilateral pulmonary infiltrates who were undergoing right-heart catheterization (RHC) to aid in diagnosis. Patients with acute coronary syndrome, end-stage renal disease, recent coronary artery bypass graft surgery, or preexisting left ventricular ejection fraction </= 30% were excluded. BNP was measured at RHC. Two intensivists independently reviewed the records to determine the final diagnosis.


RESULTS
Eighty patients were enrolled. Median BNP was 325 pg/mL (interquartile range [IQR], 82 to 767 pg/mL) in acute lung injury/ARDS patients, vs 1,260 pg/mL (IQR, 541 to 2,020 pg/mL) in CPE patients (p = 0.0001). The correlation between BNP and pulmonary capillary wedge pressure was modest (r = 0.27, p = 0.02). BNP offered good discriminatory performance for the final diagnosis (C-statistic, 0.80). At a cut point </= 200 pg/mL, BNP provided specificity of 91% for ARDS. At a cut point >/= 1,200 pg/mL, BNP had a specificity of 92% for CPE. Higher levels of BNP were associated with a decreased odds for ARDS (odds ratio, 0.4 per log increase; p = 0.007) after adjustment for age, history of CHF, and right atrial pressure. BNP was associated with in-hospital mortality (p = 0.03) irrespective of the final diagnosis and independent of APACHE (acute physiology and chronic health evaluation) II score.


CONCLUSIONS
In ICU patients with hypoxemic respiratory failure, BNP appears useful in excluding CPE and identifying patients with a high probability of ARDS, and was associated with mortality in patients with both ARDS and CPE. Larger studies are necessary to validate these findings.
Karmpaliotis
Dimitri
D
Cardiology of Georgia, Piedmont Hospital, Fuqua Heart Center, 95 Collier Rd NW, Suite 2075, Atlanta, GA 30309, USA. dkarmpaliotis@cardioga.com
Kirtane
Ajay J
AJ
Ruisi
Christopher P
CP
Polonsky
Tamar
T
Malhotra
Atul
A
Talmor
Daniel
D
Kosmidou
Ioanna
I
Jarolim
Petr
P
de Lemos
James A
JA
Sabatine
Marc S
MS
Gibson
C Michael
CM
Morrow
David
D
D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D006328:Cardiac Catheterization; D003937:Diagnosis, Differential; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000097:blood / Q000150:complications* / Q000175:diagnosis; D006760:Hospitalization; D006801:Humans; D000860:Hypoxia / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D007118:Immunoassay; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D011379:Prognosis; D011654:Pulmonary Edema / Q000097:blood / Q000150:complications* / Q000175:diagnosis; D011669:Pulmonary Wedge Pressure; D012131:Respiratory Insufficiency / Q000097:blood / Q000175:diagnosis* / Q000209:etiology; D012189:Retrospective Studies; D013318:Stroke Volume; D016278:Ventricular Function, Right; D017725:Ventricular Pressure
D015415:Biomarkers; D020097:Natriuretic Peptide, Brain