Correct Answer: C

Rationale: Corrected Rationale: The nurse should monitor the client's INR to determine the effectiveness of warfarin therapy. INR monitoring is crucial as it reflects the blood's ability to clot properly. Warfarin is commonly used as an anticoagulant, and maintaining the INR within the therapeutic range ensures that the client is protected from both clotting and bleeding events. Monitoring serum calcium levels, platelet count, or WBC count is not directly related to assessing the effectiveness of warfarin therapy.

Correct Answer: C

Rationale: Auscultating crackles in the lung bases indicates fluid in the lungs, which can be a sign of aspiration pneumonia or pulmonary edema and requires immediate intervention to prevent respiratory distress. Aspirating 100 mL of gastric residual is within the acceptable range and does not require immediate intervention. A gastric pH of 4 is normal for gastric contents. Checking residual every 6 hours is a routine nursing intervention and does not indicate an urgent issue like pulmonary complications.

Correct Answer: A

Rationale: The most crucial nursing action for a patient post-surgery is to monitor vital signs. Monitoring vital signs helps in detecting early signs of complications such as hemorrhage, shock, or infection. While monitoring the surgical site is important for assessing wound healing and signs of infection, it is secondary to monitoring vital signs. Checking blood pressure and oxygen saturation are also important, but they are components of monitoring vital signs.

Correct Answer: A

Rationale: The correct initial action for a patient with chest pain is to administer oxygen. Chest pain can be caused by insufficient oxygenation, and providing oxygen helps alleviate the pain by increasing oxygen levels in the blood. Administering nitroglycerin or morphine may be appropriate based on the underlying cause of the chest pain, but oxygen should be given first to ensure the patient's oxygen supply is adequate. Surgery is not typically the initial intervention for chest pain.

Correct Answer: A

Rationale: The correct answer is to 'Assess the patient for injuries' when a patient experiences a fall. This is crucial to promptly identify any injuries and provide appropriate care. Calling for help may be necessary, but assessing the patient's condition takes precedence to ensure immediate attention to any injuries. Documenting the fall and notifying the healthcare provider would follow after the initial assessment and necessary actions have been taken.