What sign raises suspicion that a nonverbal patient is suffering from heart failure rather than COPD or asthma?

Pulmonary crackles are a key sign that raises suspicion of heart failure in a nonverbal patient. These crackling or bubbling sounds result from fluid in the alveoli of the lungs, which is often a result of congestive heart failure. In this condition, the heart's inability to pump effectively leads to fluid backing up into the lungs, causing these distinct crackles during auscultation.

In contrast, wheezing is more commonly associated with conditions like asthma or COPD, where airway constriction and inflammation lead to a high-pitched whistling sound during breathing. The use of accessory muscles indicates respiratory distress but does not specifically differentiate between heart failure and obstructive lung diseases. A dry cough can occur with various respiratory issues but is not a definitive indicator of heart failure and may also be present in other conditions.

Thus, the presence of pulmonary crackles specifically points towards heart failure as a likely cause of the patient's nonverbal distress, highlighting the importance of auscultation in differentiating between these conditions.