A nurse is caring for a client in a provider's office. For each potential client finding, click to specify if the finding is expected or unexpected for the client following their prescribed therapy. There must be at least 1 selection in every row. There does not need to be a selection in every column.

Potential Finding Expected Unexpected Current potassium level ✔ Digoxin level ✔ Reported urinary concern ✔ Current heart rate ✔ Reported current leg findings ✔ Digoxin is a cardiac glycoside that exerts a positive inotropic and negative chronotropic effect by inhibiting the sodium-potassium ATPase pump. This mechanism increases intracellular calcium, enhancing myocardial contractility while slowing the heart rate to improve cardiac output in heart failure. Therapeutic monitoring is essential because a narrow therapeutic index exists, and electrolyte imbalances, particularly hypokalemia, significantly increase the risk of digitalis toxicity and life-threatening dysrhythmias. Rationale: The current potassium level of 3.2 mEq/L is unexpected and clinically significant as it falls below the physiological range of 3.5 to 5.0 mEq/L. While digoxin itself does not typically cause potassium loss, it competes with potassium for binding sites on the ATPase pump. Low serum potassium levels sensitize the myocardium to the drug, dramatically increasing the risk of digoxin toxicity even when the drug level remains within the therapeutic range. The digoxin level of 0.8 ng/mL is expected as it sits at the lower end of the standard therapeutic window of 0.8 to 2.0 ng/mL. This concentration indicates that the medication has reached a steady state in the plasma without exceeding safety thresholds. Maintaining this therapeutic level is crucial for managing heart failure symptoms effectively while preventing the gastrointestinal and neurological complications associated with excessive cardiac glycoside accumulation. The reported urinary concern regarding increased output is an expected therapeutic outcome of improved cardiac performance. As digoxin increases the force of myocardial contraction, renal perfusion is enhanced, which stimulates the kidneys to increase glomerular filtration and urine production. This natural diuresis helps the body mobilize and excrete excess fluid volume that had previously accumulated in the tissues due to pump failure. The current heart rate of 82/min is expected and demonstrates a positive response to the negative chronotropic effects of cardiac glycoside therapy. Digoxin slows the conduction through the atrioventricular node and increases vagal tone, which effectively lowers the heart rate from the initial tachycardic state of 102/min. A resting heart rate between 60 and 100/min indicates that the medication is successfully reducing myocardial workload. The reported current leg findings of decreased swelling are expected because they indicate a reduction in peripheral edema. By improving the heart's ability to circulate blood efficiently, digoxin reduces the venous hydrostatic pressure that causes fluid to leak into the interstitial spaces of the lower extremities. This clinical improvement correlates with the client's report of easier breathing and reflects successful management of congestive symptoms.