What is the value of B-type natriuretic peptide testing for diagnosis, prognosis or monitoring of critically ill adult patients in intensive care?

BACKGROUND: B-natriuretic peptide (BNP) and aminoterminal proBNP (NT-proBNP) are clinically useful for the diagnosis of decompensated heart failure and for prognosis in heart failure and acute coronary syndromes. Clinical use of these biomarkers in critically ill patients being treated in intensive care is not well established.

METHODS: This is a narrative review of evidence identified searching MEDLINE with the strategy [(BNP OR NT-proBNP) AND (critical illness AND intensive care)]. Seven primary reports and two narrative reviews were retrieved. For completeness, literature from each of the following searches was reviewed: [(BNP OR NT-proBNP) AND (critical illness)] and [(BNP OR NT-proBNP) AND (intensive care)].

RESULTS: Primary literature used BNP and NT-proBNP for diagnosis, prognosis and monitoring. For diagnosis of acute lung injury in unselected intensive care patients and for diagnosis of heart failure in trauma patients, the biomarkers had low sensitivity and are of modest use. BNP and NT-proBNP were found to have a significant ability to prognosticate adverse outcomes in critically ill patients. A single paper examined the use of BNP as a non-invasive replacement for pulmonary capillary wedge pressure, finding little value. The impact of renal insufficiency on the markers was noted as a confounder in most studies. In the secondary searches, some preliminary data suggested a possible role for the natriuretic peptides in exclusion of a cardiac cause for certain conditions among intensive care unit (ICU) patients. However, the general findings were that the performance of BNP and NT-proBNP is unimpressive among ICU patients.

CONCLUSIONS: Currently, utilization of BNP and NT-proBNP does not appear to provide much useful information or have a substantial role in the care of critically ill patients in intensive care.