N-terminal pro-brain natriuretic peptide is a useful diagnostic marker for transfusion-associated circulatory overload.

Background: Transfusion-associated circulatory overload (TACO) can be difficult to diagnose and distinguish from transfusion-related acute lung injury (TRALI), but is a relatively common complication that occurs when increases in blood volume overwhelm the cardiovascular system. Brain natriuretic peptide (BNP) has been shown to be a functional marker for TACO. N-terminal pro-brain natriuretic peptide (NT-proBNP) is another marker that could be more helpful than BNP since it has a longer half-life in circulation and is also much more stable in laboratory samples. In this study, whether NT-proBNP is a useful diagnostic marker for TACO was evaluated.
Study Design and Methods: Forty patients were enrolled into a case-control study (16 patients with TACO and 24 control patients) and had pre- and posttransfusion NT-proBNP concentrations evaluated from submitted type-and-screen blood samples.
Results: The sensitivity of elevated posttransfusion NT-proBNP to diagnose TACO was 93.8 percent, the specificity was 83.8 percent, and the accuracy was 87.5 percent. Elevated posttransfusion NT-proBNP is the only independent variable for the diagnosis of TACO based on multivariate logistic regression.
Conclusion: NT-proBNP is both a sensitive and a specific marker for TACO and can be helpful in confirming transfusion associated fluid overload. This study also demonstrates that many patients who experience TACO may already be in a state of excess volume. Clinicians should be aware that many asymptomatic patients have excess fluid and transfusion may cause these patients to become symptomatic.