Correct Answer: B

Rationale: An activated partial thromboplastin time (aPTT) of 90 seconds is elevated, indicating a risk of bleeding. The appropriate action for the nurse is to notify the healthcare provider. Increasing the heparin infusion rate can further elevate the aPTT, leading to an increased risk of bleeding. Applying pressure to the injection site is not relevant in this situation. Administering protamine sulfate is used to reverse the effects of heparin in cases of overdose or bleeding, but it is not the initial action for an elevated aPTT.

Correct Answer: A

Rationale: The correct instruction for applying a fentanyl (Duragesic) patch is to place it on a clean, dry, and hairless area of the skin. This ensures proper adhesion of the patch and optimal absorption of the medication. Using a heating pad over the patch is contraindicated as it can increase drug absorption and lead to overdose. Changing the patch daily is necessary for some medications, but fentanyl patches are usually changed every 72 hours to maintain a steady blood level of the medication. Placing the patch on the same site with each application can lead to skin irritation, uneven drug absorption, and should be avoided to allow the skin to recover between applications.

Correct Answer: C

Rationale: The correct instruction for a client prescribed levothyroxine (Synthroid) is to take the medication on an empty stomach. This ensures optimal absorption of levothyroxine. Taking it with a meal can interfere with absorption due to food interactions. Taking it at bedtime may lead to inconsistent absorption as it should be taken at the same time every day in the morning. Taking it with an antacid can reduce the absorption of levothyroxine, making it less effective.

Correct Answer: B

Rationale: In a client with heart failure, decreased pedal edema is a positive indicator of improved cardiac output and reduced fluid retention. Digoxin works by increasing the strength of the heart's contractions, leading to improved circulation and reduced symptoms of heart failure, such as edema. Monitoring for decreased pedal edema is essential to assess the effectiveness of digoxin therapy. Choices A, C, and D are incorrect because an increased heart rate, elevated blood pressure, and improved urine output are not specific indicators of digoxin's effectiveness in managing heart failure. Instead, the focus should be on improvements related to fluid retention and cardiac function, like decreased pedal edema.

Correct Answer: B

Rationale: A serum potassium level of 2.8 mEq/L is critically low and can cause cardiac arrhythmias, requiring immediate intervention. Hypokalemia is a life-threatening condition that needs prompt correction to prevent serious complications. High serum glucose levels (choice A) are a concern in diabetes but do not pose an immediate life-threatening risk compared to severe hypokalemia. Serum sodium (choice C) and serum bicarbonate levels (choice D) are within normal ranges and do not require immediate intervention.