Noninvasive volume assessment in the emergency department: a look at B-type natriuretic peptide and bioimpedance...

B-type natriuretic peptide (BNP) and bioimpedance vector analysis (BIVA) are potential methods of assessing fluid status in patients. Their speed and ease of implementation allows them to be used at the point of care. Currently, BNP is pivotal in the diagnosis and prognosis of heart failure, and is starting to be implemented in other diseases (e.g. acute coronary syndrome and end-stage renal disease). Although it can be elevated from volume-overload-induced cardiac stress, when assessing volume this method is ultimately unreliable since it lacks adequate specificity and accuracy. Alternatively, BIVA is accurate and sensitive in the detection of fluid status, but cannot be used to tell the etiology of the volume aberration. Despite being relatively new, BIVA is becoming recognized as a superior method to assess volume.