The patient with asthma is prescribed a leukotriene modifier drug, montelukast (Singulair). Which statement describes an advantage of this medication?

Correct Answer: B

Rationale: The correct answer is B because montelukast is a leukotriene modifier that works by reducing inflammation and promoting bronchodilation in asthma patients. This helps in managing asthma symptoms and improving lung function. A is incorrect because montelukast can cause mild GI side effects such as nausea and diarrhea. C is incorrect because while montelukast helps in controlling asthma symptoms, it does not provide immediate relief during acute episodes. D is incorrect because montelukast is typically used as an add-on therapy and not as a replacement for all other asthma medications.

Correct Answer: C

Rationale: The correct answer is C: Paroxysmal nocturnal dyspnea. This finding describes the sudden onset of severe shortness of breath at night, commonly seen in patients with chronic heart failure due to fluid redistribution when lying down. Orthopnea (A) is difficulty breathing when lying flat, not specifically at night. Pulsus alternans (B) is a regular rhythm with alternating strong and weak pulses, not related to this patient's symptom. Acute bilateral pleural effusion (D) is a buildup of fluid in the lungs, not a sudden onset symptom like in this case.

Correct Answer: D

Rationale: Failed to generate a rationale of 500+ characters after 5 retries.

Correct Answer: B

Rationale: The correct answer is B: 1 gram of pure Hb can combine with 1.34 - 1.39 ml of oxygen. This is correct because each gram of hemoglobin can bind with approximately 1.34 - 1.39 ml of oxygen, facilitating efficient oxygen transport in the blood. A is incorrect because while a small amount of oxygen is transported as dissolved oxygen, the majority is transported bound to hemoglobin. C is incorrect because arterial pO2 reflects the oxygen content in the blood, not just the hemoglobin levels. D is incorrect because CO2 is actually 20 times more soluble than oxygen, not 200 times.

Correct Answer: C

Rationale: The correct answer is C: Using a high-flow venturi mask to deliver oxygen as prescribed. This is the best option as it directly addresses the issue of promoting adequate gas exchange in a patient with advanced COPD. The high-flow venturi mask delivers oxygen at a precise concentration, ensuring optimal oxygenation. Encouraging the patient to drink fluids (A) is important for overall health but does not directly address gas exchange. Keeping the patient in semi-Fowler's position (B) can help with breathing but is not as effective as providing supplemental oxygen. Administering a sedative (D) can further depress the respiratory system and worsen gas exchange, making it an inappropriate choice.