A nurse is reinforcing teaching with a parent of a 4-month-old infant during a home visit.

Which of the following statements by the parent indicates an understanding of the teaching?

The correct answer is choice A. INR.

Warfarin is a vitamin K antagonist that inhibits the synthesis of factors II, VII, IX, and X in the liver.

These factors are part of the extrinsic and common pathways of coagulation, which are measured by the prothrombin time (PT) and the international normalized ratio (INR).

The INR is a standardized way of reporting the PT that accounts for the variability of different reagents and instruments.

The INR is used to monitor the therapeutic effect of warfarin and to adjust the dose accordingly.

The target INR range depends on the indication for warfarin, but it is usually between 2 and 3 for most conditions.

Choice B is wrong because fibrinogen level is not affected by warfarin.

Fibrinogen is a precursor of fibrin, which forms the final step of the coagulation cascade.

Fibrinogen level can be decreased in conditions such as disseminated intravascular coagulation (DIC), liver disease, or severe bleeding. Choice C is wrong because aPTT is not affected by warfarin.

aPTT measures the intrinsic and common pathways of coagulation, which are mainly dependent on factors VIII, IX, XI, and XII.

These factors are not inhibited by warfarin.

aPTT is used to monitor the effect of heparin, a direct antithrombin agent that inhibits thrombin and factor Xa.

Choice D is wrong because platelet count is not affected by warfarin.

Platelets are cell fragments that adhere to damaged blood vessels and form aggregates to initiate hemostasis.

Platelet count can be decreased in conditions such as immune thrombocytopenia (ITP), heparin-induced thrombocytopenia (HIT), or bone marrow suppression.

Normal ranges:

• INR: 0.8-1.2
• Fibrinogen: 200-400 mg/dL
• aPTT: 25-35 seconds
• Platelet count: 150-450 x 10^9/L References:

Choice A reason:

Completing an incident report is not the correct action. An incident report should be completed as part of the hospital's protocol to document the medication error and ensure appropriate follow-up and investigation.

Choice B reason:

Checking the client for indications of bleeding is the correct action to be taken. In this situation, the nurse's first priority should be to assess the client for indications of bleeding, as the client received a significantly higher dose of IV heparin than prescribed. Heparin is an anticoagulant medication used to prevent blood clots, and an overdose can increase the risk of bleeding.

After administering the wrong dose of medication, the nurse's immediate concern is the client's safety and well-being. Checking for signs of bleeding, such as petechiae, ecchymosis, hematomas, bleeding gums, melena (black, tarry stools), haematuria (blood in urine), or any other unusual bleeding, is crucial.

Choice C reason:

Monitor the client's aPTT levels: This is not the correct action to be taken. Monitoring the client's activated partial thromboplastin time (aPTT) levels is essential to assess the client's coagulation status and determine if the overdose of heparin has affected their clotting ability. The healthcare provider may adjust the heparin dosage based on the aPTT levels.

Choice D reason:

Notify the risk manager: This is not the correct action to be taken. The risk manager or appropriate supervisor should be informed about the medication error as soon as possible to initiate a thorough review of the incident and take necessary steps to prevent similar errors in the future.