What symptom should a nurse evaluate a client for when administering digoxin to detect potential toxicity?

When administering digoxin, it is crucial to evaluate for symptoms that may indicate potential toxicity, and one of the most significant indicators is visual changes, such as blurred or yellow vision. Digoxin acts on the heart to improve contractility and regulate heart rhythm, but it has a narrow therapeutic range. As levels increase beyond this range, various symptoms of toxicity emerge.

Visual disturbances occur because digoxin affects the ocular system through its interaction with sodium and potassium levels in the body, which can lead to changes in color perception and other visual anomalies. Patients might report seeing halos around lights or a yellow tint to their vision. This symptom is directly linked to digoxin toxicity and is a critical warning sign that necessitates further evaluation and, potentially, intervention.

While nausea, vomiting, and diarrhea are indeed associated with digoxin toxicity, they are less specific compared to the visual changes. Increased heart rate may suggest other problems or complications rather than digoxin toxicity itself. Enhanced appetite and energy levels do not relate to concerns about digoxin levels; rather, they could indicate improved heart performance or other unrelated factors. Therefore, the presence of visual disturbances is a more distinctive and critical symptom to monitor for patients on digoxin.