A client comes to the emergency department with severe dyspnea and a cough. Vital signs are temperature 99.2 F (37.3 C), blood pressure 108/70 mm Hg, heart rate 88/min, and respirations 24/min. The client has a history of chronic obstructive pulmonary disease (COPD) and chronic heart failure. Which diagnostic test will be most useful to the nurse in determining if this is an exacerbation of heart failure?

Question

Quizplus · Accepted Answer

BNP is a peptide that causes natriuresis. B-type natriuretic peptides are made, stored, and released primarily by the ventricles. They are produced in response to stretching of the ventricles due to the increased blood volume and higher levels of extracellular fluid (fluid overload) that accompany heart failure. Elevation of BNP >100 pg/mL helps to distinguish cardiac from respiratory causes of dyspnea. (Option A) ABGs will be helpful in determining the client's oxygenation status and acid-base balance but will not determine whether the cause of the dyspnea is cardiac or respiratory. (Option C) CK-MB is a cardiospecific isozyme that is released in the presence of myocardial tissue injury. Elevations are highly indicative of a myocardial infarction but not specific for heart failure. (Option D) A chest x-ray can show heart enlargement in the case of heart failure and may show infiltrations in the lungs. Pneumonia can also exacerbate COPD and can be confused with heart failure infiltrates. Chest x-ray is not as specific to heart failure as the BNP lab test. Educational objective: Elevation of BNP to >100 pg/mL is seen in heart failure. It aids in the assessment of the severity of heart failure and helps distinguish cardiac from respiratory causes of dyspnea.

A Client Comes to the Emergency Department with Severe Dyspnea