Digoxin Case Study

Evidence-based Recommendations
In the actual treatment plan of the case study, amiodarone was ordered. I was curious about why digoxin was not used in this case. I did research and found a randomized clinical trial published 3 months ago studied on whether amiodarone is more effective than digoxin in AF rate control. Participants were randomized into amiodarone or digoxin treatment groups. The results indicated that in AF patients with contraindications for beta-blockers or calcium channel blockers, patients who received amiodarone resulted in significant lower failure rate (21.4% in amiodarone group vs 59.5% in digoxin group) and a faster response than those who received digoxin treatment (56.66 ± 39.52 minutes with amiodarone vs 135.38 ±
110.41 minutes with digoxin treatment).
In this case study, the medical intervention used amiodarone instead of digoxin; I think this is a good decision because now the evidence has been shown that amiodarone has a high chance
of success and a faster response. Especially the patient has symptoms of pulmonary distress, so beta-blockers are contraindicated. In addition, it is critical that the patient who has a new onset of AF is treated timely and effectively. It is a better choice to treat this patient with amiodarone based on this study (Shojaee, Feizi, Miri, Etemadi, and Feizi, 2017).
The patient’s morning labs included a chemistry panel, a complete blood count and a coagulation panel. The abnormal lab values are potassium of 3.2 mEq/L and magnesium of 1.2 mEq/L. It’s not surprising that patient’s potassium level is low because smoking, alcohol drinking and long term use of hypertension medication, hydrochlorothiazide, can cause malabsorption and result in hypokalemia and hypomagnesemia (Pagana & Pagana, 2015). Unfortunately, patient can’t resolve this problem from his diet due to malabsorption. Potassium and magnesium are triggers of atrial fibrillation because hypokalemia affects the patient’s heart rate and contractility and hypomagnesemia increases the cardiac dysrhythmia (Pagana & Pagana, 2015). He is also scheduled for transesophageal echocardiogram (TEE) but is not done yet. TEE can confirm if blood clot exists in the atria. I would expect a clear picture of the heart including the atria, the valves and the size and wall thickness of the heart to identify the structural changes in the heart from this diagnostic test (Ignatavicius and Workman, 2016).
Values to Monitor and Related Interventions
The nurse should monitor the electrolytes including potassium and magnesium Q6h or at least daily to manage the condition promptly.
Potassium is very important in maintain cardiac function. At low potassium levels, heart cells become more excitable and result in premature contraction and result in atrial fibrillation. In AF, the atrial contractions are impaired which lead to the blood pooling in the atria and increase the risk of blood clot, stroke, and congestive heart failure. To prevent the blood clot and stroke, heparin, an anticoagulant, and aspirin, an antiplatelet aggregation agent, are prescribed. It is critical to monitor and adjust the heparin level to meet the PTT goal of 45-55 seconds; assess any signs of bleeding, rash, chills, fever, itching and signs of heparin induced thrombocytopenia (HIT). Amiodarone, an antiarrhythmic agent, is prescribed for treating ventricular tachycardia and dysrhythmia. Hydrochlorothiazide is on hold because the patient is under hypokalemia and his BP value is 96/74 mmHg due to the new onset of AF or antihypertensive medication. The medications like amiodarone and hydrochlorothiazide can cause hypotension and bradycardia, so monitor heart rate, BP, and cardiac rhythm. In addition, diltiazem, a calcium channel blocker, was given after admission to dilate blood vessels and relax the heart muscles to reduce the heart
rate.
Additional Diagnostic Testing and Treatment
In addition to the orders of CBC, chemistry panel and coagulation panel tests. A renal panel and a liver panel are indicated in the diagnostic test to monitor the kidney and liver function due to renal and hepatic toxicity of the medications (Skidmore-Roth, 2016). AF increases the risk of heart failure, troponin, B-type natriuretic peptide (BNP) should be included in the labs to monitor the signs of heart failure (Ignatavicius and Workman, 2013). Amiodarone level should be measured to establish an effective therapeutic dose. LDL is one of the leading cause of plaque in the arteries, so cholesterol levels should also be checked to have a better image on how to give effective diet and treatments. Electrocardiogram is also useful to monitor the characteristics of the cardiac condition. Patient also has crackles over the lung fields and dyspnea on exertion, so the oxygen perfusion and respiratory characters should be assessed routinely. Patient also has pitting edema in lower extremities, monitor input and output, weigh the patient daily and report weight change if necessary. In addition, there are several procedures useful to restore the heart rhythm to a normal level. First, chemical or electrical cardioversion use drugs or low energy electric shock to trigger a normal rhythm. Second, catheter ablation is an alternative if the medications and electrical cardioversion don’t work. Third, pacemaker, the doctor can also use catheter ablation technology to destroy the atrioventricular node and surgically implant a pacemaker to maintain a normal heart rhythm. Fourth, a surgical maze procedure is a more invasive procedure to treat the AF.