Cardiac Glycosides And Diuretics

1. Which of the following co-morbidities increase a patient's risk in developing digoxin toxicity?

Heart Failure

Renal Failure

Parkinson's disease

Dementia

Because 60-90% of digoxin is excreted unchanged by the kidneys, even the modest renal impairment can dramatically hasten the accumulation of digoxin to toxic concentrations in the body. Assessment of renal function prior to therapy is important in determining the proper dosing regimen. This is particularly important in elderly patients in which renal impairment is common. One of the main indications for use of digoxin is in the treatment of heart failure to increase contractility and decrease the workload of the heart. Concurrent neurological disorders such as Parkinson's and dementia do not impact the pharmacokinetics of digoxin.

Explanation

Because 60-90% of digoxin is excreted unchanged by the kidneys, even the modest renal impairment can dramatically hasten the accumulation of digoxin to toxic concentrations in the body. Assessment of renal function prior to therapy is important in determining the proper dosing regimen. This is particularly important in elderly patients in which renal impairment is common. One of the main indications for use of digoxin is in the treatment of heart failure to increase contractility and decrease the workload of the heart. Concurrent neurological disorders such as Parkinson's and dementia do not impact the pharmacokinetics of digoxin.

2. When a patient is receiving diuretic therapy, which of the following would best reflect the patient's fluid volume?

Blood pressure and pulse

Serum potassium and sodium levels

Intake, output, and daily weights

Measurements of abdominal girth and calf circumference

Diuretics produce a net loss of fluids. Assessment of their effectiveness is reflected in weight change. Excess fluid loss indicates a reduction in fluid in the vascular and extravascular compartments. Measuring I & O is important to the total management of a fluid imbalance.

Explanation

Diuretics produce a net loss of fluids. Assessment of their effectiveness is reflected in weight change. Excess fluid loss indicates a reduction in fluid in the vascular and extravascular compartments. Measuring I & O is important to the total management of a fluid imbalance.

3. Which of the following is the priority intervention for the nurse prior to administering digoxin (lanoxin)?

Palpate pedal pulses for quality and strength

Monitor renal function lab values

Auscultate the apical pulse for one full minute

Assess serum potassium levels

It is critical to auscultate the apical pulse for one full minute prior to administration of digoxin. This is a PRIORITY nursing action. Digoxin slows the heart rate thus the dose would be held for a AP less than 60 bpm. Bradycardia is also a potential sign of digoxin toxicity again warranting the drug be held for AP

Explanation

It is critical to auscultate the apical pulse for one full minute prior to administration of digoxin. This is a PRIORITY nursing action. Digoxin slows the heart rate thus the dose would be held for a AP less than 60 bpm. Bradycardia is also a potential sign of digoxin toxicity again warranting the drug be held for AP

4. The nurse is scheduled to administer a dose of digoxin (Lanoxin) to an adult client with atrial fibrillation. The client has a potassium level of 4.6 mEq/L. The nurse interprets that the:

Dose should be omitted only for that day.

Client needs a dose of potassium before receiving digoxin.

Dose should be withheld and the healthcare provider notified.

Dose should be administered as ordered.

The normal reference range for potassium for an adult is 3.5 to 5.1 mEq/L. Hypokalemia can make the client more susceptible to digoxin toxicity. The nurse monitors the results of electrolytes for the potassium level. If low, the dose is withheld, and the healthcare provider notified. This client's result is within normal limits, so the dose should be administered.

Explanation

The normal reference range for potassium for an adult is 3.5 to 5.1 mEq/L. Hypokalemia can make the client more susceptible to digoxin toxicity. The nurse monitors the results of electrolytes for the potassium level. If low, the dose is withheld, and the healthcare provider notified. This client's result is within normal limits, so the dose should be administered.

5. While preparing a patient for discharge, which of the following statements should the nurse include in instructions regarding his new prescription for furosemide (Lasix)?

"Be sure to change your position slowly and rise slowly after sitting or lying to prevent dizziness and possible fainting."

"Avoid foods high in potassium, such as bananas, oranges, fresh vegetables and dates."

"If you experience weight gain such as 5 or more pounds a week, be sure to tell your physician during your next routine visit."

"Keep a monthly journal or log of your weight."

Orthostatic hypotension is a possible problem with diuretic therapy because of the diuretic-induced fluid volume loss. Dizziness or fainting with sudden changes can lead to falls and risk for injury. Foods high in potassium should be encouraged because of K+ loss with diuresis. A daily then weekly log of weights should be taken. A weight gain of 5 lb or more in a week should be reported immediately.

Explanation

Orthostatic hypotension is a possible problem with diuretic therapy because of the diuretic-induced fluid volume loss. Dizziness or fainting with sudden changes can lead to falls and risk for injury. Foods high in potassium should be encouraged because of K+ loss with diuresis. A daily then weekly log of weights should be taken. A weight gain of 5 lb or more in a week should be reported immediately.

6. While assisting a patient in getting out of bed, what objective indicator (other than a manometer) can the nurse use to detect early postural hypotension?

Pupil response

Pulse rate

State of orientation

Increased muscle rigidity

The cardiovascular system first tries to compensate for a sudden drop in circulating volume often as a result of diuretic therapy, by increasing the heart rate by sympathetic stimulation. Pupillary change results from oxygen deficit after a severe drop in BP; state of orientation can be altered by a drop in blood pressure (i.e., due to fainting) because of diminished perfusion and lack of oxygen but it is not an early sign. Muscles would become more limp rather than rigid with postural hypotension.

Explanation

The cardiovascular system first tries to compensate for a sudden drop in circulating volume often as a result of diuretic therapy, by increasing the heart rate by sympathetic stimulation. Pupillary change results from oxygen deficit after a severe drop in BP; state of orientation can be altered by a drop in blood pressure (i.e., due to fainting) because of diminished perfusion and lack of oxygen but it is not an early sign. Muscles would become more limp rather than rigid with postural hypotension.

7. A patient is started on digoxin therapy. The nurse will teach the patient to avoid taking which of the following food items concurrently with their daily dose?

High fiber cereals

Canned fruits

Spicy foods

Cooked vegetables

Do not administer oral preparations of digoxin with high fiber foods. Studies have shown that digoxin binds with fiber, thereby reducing the amount of medication available for absorption.

Explanation

Do not administer oral preparations of digoxin with high fiber foods. Studies have shown that digoxin binds with fiber, thereby reducing the amount of medication available for absorption.

8. The nurse is reviewing the medication that have been ordered for a patient for whom a loop diuretic has been newly prescribed. The loop diuretic may have a possible interaction with which of the following?

Vitamin C

Warfarin

Penicillins

NSAID's

When loop diuretics and NSAID's are taken concurrently, they can decrease the diuretic effect because these two drug classes have opposite effects on renal prostaglandin activity. Loop diuretics activate renal prostaglandins which result in dilation of blood vessels reducing renal, pulmonary, and systemic vascular resistance. NSAIDS inhibit prostaglandin activity.

Explanation

When loop diuretics and NSAID's are taken concurrently, they can decrease the diuretic effect because these two drug classes have opposite effects on renal prostaglandin activity. Loop diuretics activate renal prostaglandins which result in dilation of blood vessels reducing renal, pulmonary, and systemic vascular resistance. NSAIDS inhibit prostaglandin activity.

9. Number the nursing actions below in order of priority for the step-by-step management of digoxin toxicity. Use all actions listed below.
__1__Administer potassium supplements for hypokalemia if indicated, as ordered
__2__Begin continuous ECG monitoring for cardiac dysrhythmias
__3__Administer digoxin antidote (digoxin immune Fab, digibind), if indicated, as ordered
__4__Discontinue administration of the drug
__5__Determine serum electrolytes and serum digoxin levels

MVCR classmates: This quiz format does not allow for 'ordering' so type the numbers of the nursing actions in order of priority.

If the nurse suspects digoxin toxicity upon assessment of a patient, the priority nursing action is to withhold the drug. Next, monitor the patient for potentially life-threatening dysrhythmias with continuous ECG monitoring. Labs need to be evaluated to identify contributing factors. Hypokalemia is the most common electrolyte imbalance lending to digoxin toxicity. Once values have been determined, replacement therapy may be indicated. Finally, once the serum digoxin levels are determined, the HCP may order digibind, the antidote for severe digoxin toxicity. It binds with digoxin resulting in lower serum levels.

Explanation

If the nurse suspects digoxin toxicity upon assessment of a patient, the priority nursing action is to withhold the drug. Next, monitor the patient for potentially life-threatening dysrhythmias with continuous ECG monitoring. Labs need to be evaluated to identify contributing factors. Hypokalemia is the most common electrolyte imbalance lending to digoxin toxicity. Once values have been determined, replacement therapy may be indicated. Finally, once the serum digoxin levels are determined, the HCP may order digibind, the antidote for severe digoxin toxicity. It binds with digoxin resulting in lower serum levels.

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