Chapter 21: Critical Thinking Exercise # 3

* What specific assessment findings indicate that an older patient being treated for congestive heart failure (CHF) is not responding to Digoxin, Furosemide (Lasix), or Vasodilator therapy?

A patient should have increased urine output from diuretic therapy; hypertension/BP should decrease as a result of the diuretic and vasodilator. Heart rate will lower in a patient taking digoxin. The patient should begin to see an improvement/return to baseline in their activity tolerance and ability to preform activities of daily living. Signs and symptoms of CHF (peripheral edema, dyspnea, fatigue, jugular venous distension, crackles, etc.) should begin to resolve. Daily intake and output should be monitored, any weight gain should be reported (greater than 3lbs in 48 hours), as the goal is to reduce fluid volume to improve cardiac output and tissue perfusion. Any increase in blood pressure, heart rate, edema, difficulty breathing, mentation changes, and weight gain indicate that therapy is not effective and that CHF is not resolving.

* How would you differentiate between expected, adverse, and toxic side effects? Digoxin is used to increase contractility, which would be decreased in a patient with CHF. Digoxin may cause; visual disturbances, headaches bradycardia, nausea, anorexia, muscle weakness, and dizziness. The therapeutic range with digoxin is very narrow (0.5-2.0 ng/mL), and is toxic in excess (assess for blind spot and irregular heartbeats/pulse). Potassium levels must be monitored for patients on digoxin because hypokalemia may result from use. Never give digoxin if the heart rate is below 60 BPM, digoxin may further reduce the rate leading to cardiac arrest. Furosemide (Lasix)/diuretic therapy is initiated with CHF to reduce preload (blood volume that returns to the heart) to increase cardiac effectiveness. Diarrhea, confusion, malaise, anorexia, & ototoxicity (reversible) may occur. Electrolyte levels must be monitored; most diuretics promote the excretion of potassium and magnesium. If any signs and symptoms of hypokalemia (dysrhythmias, muscle weakness, irregular pulse) present, the diuretic should be withheld and the HCP notified. A dramatic increase in urine output is normal and expected with diuretic therapy. Vasodilators widen blood vessels to increase perfusion and reduce the workload of the heart. Hydralazine and nitrates are vasodilators used to treat CHF. Headache is common with nitrate usage but will subside. Nitrate tolerance can develop and must be given a 12-hour respite between doses. Vasodilation therapy acts to return vasculature to normal, decrease preload, and improve left ventricular function. Blood pressure should be monitored with nitrate usage to prevent hypotension.