Correct Answer: D

Rationale: The client with a pneumothorax and a pulse oximeter reading of 90% indicates potential respiratory compromise, requiring immediate attention to prevent further deterioration.

Correct Answer: B

Rationale: The correct answer is B: Diminished cough effort. Clients with myasthenia gravis often experience muscle weakness, including respiratory muscles, which can lead to diminished cough effort. This weakness can result in ineffective airway clearance, putting the client at a high risk. Pain when coughing (choice A) is not directly related to the etiology of ineffective airway clearance in myasthenia gravis. While thick, dry secretions (choice C) and excessive inflammation (choice D) can contribute to airway clearance issues, the primary concern in myasthenia gravis is the muscle weakness affecting cough effort.

Correct Answer: A

Rationale: The primary advantage of prescribing rivaroxaban over warfarin for a patient with a history of deep vein thrombosis (DVT) is that rivaroxaban does not require regular INR monitoring. This eliminates the need for frequent blood tests to adjust the dosage, making it more convenient for patients to manage their anticoagulant therapy.

Correct Answer: B

Rationale: The primary purpose of prescribing calcium acetate to a patient with chronic kidney disease (CKD) is to reduce phosphate levels. Calcium acetate binds to dietary phosphate, preventing its absorption and helping to manage hyperphosphatemia commonly seen in CKD patients.

Correct Answer: B

Rationale: Propylthiouracil (PTU) is a medication used to treat hyperthyroidism by suppressing the production of thyroid hormones. It works by inhibiting the enzyme responsible for the synthesis of thyroid hormones, thereby reducing their levels in the body. This helps to alleviate the symptoms of hyperthyroidism and restore thyroid hormone levels to normal range.