A nurse is providing teaching to an older adult client who has a seizure disorder and a new prescription for phenytoin. Which of the following instructions should the nurse include?

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:

safety followed by the client’s pain.

The nurse should first address the client’s safety because it is the most basic and essential need according to Maslow’s hierarchy of needs. The client may be at risk of abuse or neglect from his adult child, as evidenced by the bruises, body odor, unclean clothes, low BMI, and submissive behavior. The nurse should assess the client for signs of physical or emotional abuse and report any suspicions to the appropriate authorities. The nurse should also provide a safe and supportive environment for the client and encourage him to express his feelings and concerns.

The nurse should then address the client’s pain because it is a physiological need that affects the client’s comfort and well-being. The client rates his pain as 8 on a 0 to 10 scale and is not moving his right arm. The nurse should assess the client’s arm for signs of injury, such as swelling, deformity, or bleeding. The nurse should also administer analgesics as prescribed and monitor the client’s response to pain relief. The nurse should also provide non-pharmacological interventions, such as ice packs, elevation, or distraction.

The other choices are less urgent than safety and pain. The client’s abrasions are superficial and do not pose a significant risk of infection or bleeding. The client’s hygiene is important but not a priority at this time. The client’s BMI indicates that he is underweight, but this is a chronic condition that requires long-term nutritional intervention. The client’s heart rate is slightly elevated but not alarming, and may be due to pain, anxiety, or dehydration.