Question

Mrs. Jay, a 73 year old female, has been admitted to the hospital for treatment of a deep vein thrombosis in her right calf. Her PMH includes hypertension. She has been taking Capoten 12.5 mg BID with good control of her pressure.  She is ordered on bedrest with the following orders:

Heparin 5000units IV bolus, followed by a heparin drip of 25,000units in 250ml to infuse at 1000 units per hour. Follow heparin protocol that includes obtaining a stat aPTT 6 hours after initiation and 6 hours after any dose change.

1. How many mL per hour will you administer the heparin drip to deliver 1000 units per hour?

2. What is an aPTT? What is a therapeutic range?

3. How does heparin work? What precautions need to be taken?

4. What is the treatment for a heparin overdose?

After three days, the physician orders Warfarin (Coumadin) 2mg po daily.  Mrs. Jay asks why she needs to take Coumadin and the heparin.

5. How will you respond to her?

6. How does Coumadin work? What is the difference between Heparin and Coumadin?

7. What lab value will be monitored while on Coumadin? What is a therapeutic range?

8. What is the antidote for Coumadin overdose?

9. What are some nursing considerations for a patient taking anticoagulants?

10. Develop a detailed teaching plan for Mrs. Jay regarding taking Coumadin when she goes home.

Answer 1

1. 25000 units of Heparin is present in 250 mL.

The ordered dose of heparin is 1000 units per hour.

The volume in mL to be infused can be calculated as:

Þ 25000 units = 250 mL

Þ 1000 units = (250 x 1000)/25000

= 250000/25000

= 10 mL

So 1000 unit is present in 10 mL

Hence to administer 1000 units per hour, the rate of infusion is to be kept at 10 mL/hour.

2. The aPTT is one of the blood coagulation test which estimate the duration of blood takes to form a clot. aPTT stands for activated Partial Thromboplastin Time. It is used to measure the effect of heparin treatment to confirm that blood is not too much thin.

If heparin therapy is used, the range of aPTT is 45 to 70 seconds.

3. Heparin act by interfering with the formation of blood clots in blood vessels by binding to an enzyme inhibitor antithrombin III (AT) and activate AT. This activated AT causes inactivation of factor IIa (thrombin), factor Xa and other protease of the coagulation system. This inactivation of coagulating factors makes blood thin and increases time of blood coagulation.

Precaution is to be taken that a patient should not be allergic to heparin. He/she should not have low platelet counts. Patient should not be pregnant or willing to pregnant during treatment. Patient is to be checked for diseases like hypertension, liver diseases, antithrombin III deficiency, GI ulcers etc. Check history of smoking or using any tobacco product.

4. In case of heparin overdose, Protamine sulfate (1%) can be infused to neutralize the effect of heparin.

5. Caumadin is product of warfarin, which is most commonly used as blood thinner or as an anticoagulant. Heparin is more effective and faster anticoagulant compared to warfarin, and in case of emergency the heparin is infused to prevent clotting of blood. Once the situation is controlled, heparin dose is reduced and simultaneously warfarin is administered to control the clotting timing.

6. Caumadin contains warfarin which act by competitive inhibition of an enzyme i.e. the vitamin K epoxide reductase complex 1 (VKORC1), which helps for activating the vitamin K which helps to synthesized coagulating factors. Caumadin inhibits the function of vitamin K and therefore reduce the synthesis of active clotting factors.

The main difference between heparin and Caumadin is their onset of action. The heparin has high onset of action and hence in case of emergency, heparin is injected to prevent the clot formation.

7. People taking caumadin, for the therapeutic effect, the range of PT result should have range of 2.0 3.0 INR (international normalized ratio).

8. Caumadin is vitamin K antagonist and If overdose occurs, the antidote for warfarin is vitamin K (phytonadione, Aquamephyton) which can be administered to reverse the anticoagulating effect of warfarin.

9. Nursing consideration for the patient taking anticoagulants must be teached about their increased risk for bleeding, monitoring for bleeding, and the management of bleeding. Monitor side effect if any. Monitor stool or urine if any blood sample is there.

10. Teaching plan for Mrs. Jay who is taking Caumadin when she instructed to go home.

· Take medication as directed by physician.

· Do not overdose the medication.

· Inform to healthcare professional of missed doses.

· Foods with low vitamin K is to be taken.

· Caution is to be taken to avoid injury from IM injections.

· Use a soft toothbrush and shave with an electric razor.

· Report if there is any unusual symptoms (bleeding gums, nose bleeding, high menstrual flow etc.), any pain or inflammation to healthcare professional.

· Avoid consumption of alcohol or any product containing aspirin or NSAIDs.

· Report to healthcare professional if pregnancy is planned or if feeding an infant.