PART ONE Medical-Surgical Cases

1
1 Cardiovascular

Cardiovascular Disorders
Case Study 1 Heart Failure
Difficulty: Beginning
Setting: Emergency department, hospital
Index Words: heart failure (HF), cardiomyopathy, volume overload, quality of life

X Scenario

M.G., a “frequent flier,” is admitted to the emergency department (ED) with a diagnosis of heart failure
(HF). She was discharged from the hospital 10 days ago and comes in today stating, “I just had to come to the hospital today because I can't catch my breath and my legs are as big as tree trunks.” After further questioning, you learn she is strictly following the fluid and salt restriction ordered during her last hospital admission. She reports gaining 1 to 2 pounds every day
CASE STUDY PROGRESS
The next day, M.G. has shown only slight improvement, and digoxin (Lanoxin) 125 mcg PO daily is added to her orders.

8. What is the action of the digoxin? Digoxin:
a. causes systemic vasodilation.
b. promotes the excretion of sodium and water in the renal tubules.
c. increases cardiac contractility and cardiac output.
d. blocks sympathetic nervous system stimulation to the heart.
Answer: C
Digoxin works by increasing cardiac contractility, and thus increasing cardiac output.

9. Which findings from M.G.'s assessment would indicate an increased possibility of digoxin toxicity? Explain your answer.
a. Serum potassium level of 2.2 mEq/L
b. Serum sodium level of 139 mEq/L
c. Apical heart rate of 64 beats/minute
d. Digoxin level 1.6 ng/mL
Answer: A
Low potassium levels can increase the potential for digoxin toxicity. M.G. is taking furosemide, a loop diuretic that excretes potassium as well as sodium and water. Potassium levels should be monitored carefully during digoxin therapy. The other findings are within normal limits.

10. When you go to give the digoxin, you notice that it is available in milligrams (mg) not micrograms (mcg). Convert 125 mcg to mg.
125mcg = 0.125 mg
If the student answers “.125 mg” the answer should be incorrect because, per The Joint Commission
“Do Not Use” list, the leading zero should not be omitted.

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