Pharmacology Anticoagulants #7

Question

The nurse is caring for a patient receiving a continuous IV heparin infusion. The activated partial thromboplastin time (aPTT) result is 1 ½ times greater than normal. Which action should the nurse take?

Answers

  1. Document finding and continue to monitor.
    • Rationale:

      This answer is correct because 1.5 times greater than the normal is therapeutic for heparin therapy. Since the therapeutic goal of heparin is to reduce clotting, the patient’s baseline activated partial thromboplastin (aPTT) time is obtained. The desired blood level to produce the therapeutic effect is 1.5 to 2.5 times the patient’s normal (baseline) aPTT level. Blood tests will reveal if it is safe to administer this medication but mostly utilized to adjust or titrate heparin dosages during therapy. The aPTT levels will be m

  2. Call for prothrombin PT to confirm.
    • Rationale:

      This answer is not correct because prothrombin time (PT) is a different blood level monitored when patients are on warfarin therapy. Another blood level often checked with PT is international ratio (INR). Activated partial thromboplastin (aPTT) is a blood result used to monitor a patient’s clotting time. It is also monitored during heparin therapy to determine the need for titration of the medication to assure therapeutic, yet non-toxic levels are maintained. The desired blood level to produce the therapeutic effect is 1.5 to 2.5 times the patien

  3. Discontinue the heparin infusion
    • Rationale:

      This answer is not correct because since the aPTT level is 1.5 times the baseline, this level is within the therapeutic level. It should not be discontinued or the patient would be at risk of thromboembolic events including pulmonary embolism, stroke, and myocardial infarction.

  4. Perform a stool guaiac test.
    • Rationale:

      This answer is not correct because the scenario does not indicate the patient is bleeding. Although there is a risk of bleeding, including gastrointestinal bleeding, the aPTT level is now just 1.5 times the patient’s baseline so there is little risk. This should be a test performed if the patient’s level had a sustained level of > 2.5 times the patient’s baseline. It would not be the priority action, but would be a way to determine if the patient is experiencing gastrointestinal bleeding from elevated levels of heparin. If the patient’s levels indicate an overdose has occurred and dangerous bleeding is an

Overview

Activated partial thromboplastin (aPTT) is a blood result used to monitor a patient’s clotting time. It is also monitored during heparin therapy to determine the need for titration of the medication to assure therapeutic, yet non-toxic levels are maintained. The desired blood level to produce the therapeutic effect is 1.5 to 2.5 times the patient’s normal (baseline) aPTT level.

Explanation

The correct answer is A. aPTT expected result is 1.5-2.5 times the control; however, signs of hemorrhage or other bleeding should also be assessed. Selection B is incorrect since its usefulness is usually for warfarin. Selection C is incorrect since there is no evidence to warrant discontinuing the heparin. Selection D is incorrect. Assessing for bleeding is important but stool for blood is not necessary at this time.

Learning Outcomes

Heparin is an anticoagulant and therapy is indicated for patients with serious conditions, including pulmonary embolism, myocardial infarction, and other thromboembolic conditions, to help prevent further blood clots from forming. Since the therapeutic goal of heparin is to reduce clotting, the patient’s baseline activated partial thromboplastin (aPTT) time is obtained. The desired blood level to produce the therapeutic effect is 1.5 to 2.5 times the patient’s normal (baseline) aPTT level. Blood tests will reveal if it is safe to administer this medication but mostly utilized to adjust or titrate heparin dosages during therapy. The aPTT levels will be monitored throughout therapy. If the patient’s levels indicate an overdose has occurred and dangerous bleeding is anticipated, the antidote, protamine sulfate, may be indicated.

Test Taking Tip

Knowing important labs associated with therapeutic levels and toxicity of medication cannot be overemphasized. Know these blood levels and monitor patients carefully for clinical manifestations.

Video Rationale