A 74-year-old woman comes to the urgent care clinic with nausea, lethargy, and decreased appetite for the past several days. She has also had increasing fatigue and occasional palpitations. Medical conditions include persistent atrial fibrillation and nonischemic cardiomyopathy. Left ventricular ejection fraction measured 3 months ago was 25%. Medications include furosemide, valsartan, metoprolol, digoxin, and apixaban. She has smoked one pack of cigarettes daily for the past 50 years. Blood pressure is 105/75 mm Hg and pulse is 55/min and irregularly irregular. She is afebrile. Lung auscultation reveals occasional scattered wheezes. The abdomen is soft and nontender with a liver span of 8 cm and nonpalpable spleen. There is no ankle edema. Neurologic examination shows no focal deficits. ECG shows atrial fibrillation and nonspecific T wave changes. Fingerstick glucose level is 78 mg/dL. Which of the following is the best initial test for this patient?

Question

A 74-year-old woman comes to the urgent care clinic with nausea, lethargy, and decreased appetite for the past several days.  She has also had increasing fatigue and occasional palpitations.  Medical conditions include persistent atrial fibrillation and nonischemic cardiomyopathy.  Left ventricular ejection fraction measured 3 months ago was 25%.  Medications include furosemide, valsartan, metoprolol, digoxin, and apixaban.  She has smoked one pack of cigarettes daily for the past 50 years.  Blood pressure is 105/75 mm Hg and pulse is 55/min and irregularly irregular.  She is afebrile.  Lung auscultation reveals occasional scattered wheezes.  The abdomen is soft and nontender with a liver span of 8 cm and nonpalpable spleen.  There is no ankle edema.  Neurologic examination shows no focal deficits.  ECG shows atrial fibrillation and nonspecific T wave changes.  Fingerstick glucose level is 78 mg/dL.  Which of the following is the best initial test for this patient?

Quizplus · Accepted Answer

11ec25c8_d33e_aeb0_bc81_63067aa3eb0f_MD0003_00 Digoxin is effective in treating atrial fibrillation and heart failure with reduced ejection fraction; however, the drug has a narrow therapeutic window and toxicity is common. Because digoxin is renally cleared, elderly patients who are susceptible to dehydration and acute kidney injury are particularly prone to toxicity. Acute digoxin toxicity most commonly presents with gastrointestinal symptoms (eg, anorexia, nausea, vomiting) as well as lethargy and fatigue. Chronic toxicity more prominently involves neurologic and visual symptoms (eg, confusion, changes in color vision). Cardiac arrhythmias, including sinus bradycardia and atrioventricular block, are also common with toxicity and may cause palpitations. This elderly patient is at risk for dehydration due to use of furosemide, and she has likely experienced reduced digoxin clearance, leading to acute toxicity. The collection of a blood digoxin level helps confirm the diagnosis; however, toxicity can occur even with normal blood levels and in such cases should be recognized by consistent clinical features. Treatment involves drug discontinuation, intravenous hydration, and in severe cases the administration of digoxin-specific antibody (Fab) fragments. (Choice B) This patient's smoking history suggests underlying chronic obstructive pulmonary disease as the cause of her wheezing. However, without dyspnea or other respiratory symptoms, chest x-ray is not indicated at this time. (Choice C) Coagulation parameters are generally unhelpful in monitoring for efficacy or overdose with factor Xa inhibitors (eg, apixiban). In addition, this patient has no evidence of acute bleeding. (Choice D) ECG stress test is appropriate for suspected coronary artery disease. Nausea is sometimes representative of angina, but drug toxicity is more likely in the absence of a history of chest pain. (Choice E) This patient has no edema, dyspnea, or other evidence of heart failure decompensation; therefore, repeat echocardiography is not indicated at this time. (Choice F) Lumbar puncture is appropriate for suspected meningitis, which typically presents with fever, headache, and confusion and is highly unlikely in this patient. (Choice G) Thyroid function studies can diagnose hypothyroidism, which can present with lethargy, fatigue, and anorexia. However, the acuity of this patient's symptoms combined with the potential for toxicity with digoxin should raise higher suspicion for drug toxicity. Educational objective: Digoxin has a narrow therapeutic window and toxicity is common in elderly patients as they are susceptible to acute renal dysfunction with decreased clearance of the drug. Symptoms of toxicity include gastrointestinal disturbances (eg, anorexia, nausea, vomiting), neurologic disturbances (eg, confusion, changes in color vision), and cardiac arrhythmias. References: Recognition and management of digitalis intoxication: implications for emergency medicine (http://www.ncbi.nlm.nih.gov/pubmed/1997019)

A 74-Year-Old Woman Comes to the Urgent Care Clinic with Nausea