The nurse is caring for a 30-year-old American Indian female who is taking Rifater, a drug containing rifampin, isoniazid, and pyrazinamide. The patient asks how long she will have to take the medication. Which response explains when the patient may discontinue the medication?

Correct Answer: C

Rationale: The correct answer is C: When three consecutive sputum cultures are negative. This indicates successful treatment completion and eradication of the tuberculosis infection. A negative sputum culture confirms that the patient is no longer infectious and can safely discontinue the medication. Choice A is incorrect because a single negative sputum culture does not guarantee complete eradication of the infection. Choice B is incorrect as the standard treatment duration for tuberculosis is typically 6-9 months, but discontinuation should be based on sputum culture results. Choice D is incorrect as the TST can remain positive even after successful treatment, as it reflects exposure to the tuberculosis bacteria, not active infection status.

Correct Answer: D

Rationale: The correct answer is D: Milk. Milk is a high sodium food and can contribute significantly to a patient's daily sodium intake. For a patient on a 2000-mg sodium diet, it is crucial to limit high sodium foods like milk to prevent fluid retention and worsening of heart failure symptoms. Other choices (A, B, C) are lower in sodium compared to milk. Chicken, fresh spinach, and eggs are generally good protein sources with lower sodium content and can be included in moderation in a 2000-mg sodium diet for a heart failure patient.

Correct Answer: D

Rationale: The correct answer is D: Molecular weight of gas. Diffusion rate is inversely proportional to the square root of the molecular weight of the gas. This means that as the molecular weight increases, the diffusion rate decreases. This is because heavier molecules move more slowly and have a harder time diffusing through a medium. Surface area for diffusion, concentration gradient, and solubility of gas all directly affect diffusion rate. Increasing the surface area for diffusion allows for more space for molecules to diffuse, a steeper concentration gradient increases the rate of diffusion, and higher solubility of gas in a medium enhances the diffusion rate.

Correct Answer: C

Rationale: The correct answer is C because in the upright lung, the ventilation-perfusion ratio is higher at the top due to gravity causing increased perfusion at the bases. This results in a mismatch between ventilation and perfusion, leading to a higher V/Q ratio at the top. Choices A and B are incorrect because ventilation is actually greater at the bases due to the effect of gravity, leading to higher ventilation there. Choice D is incorrect because PO2 is higher at the apex of the lung due to decreased perfusion but not at the bases.

Correct Answer: C

Rationale: Step-by-step rationale for why "Encourage coughing and deep breathing" (Choice C) is the correct answer: 1. After pneumonectomy, patient is at risk for lung complications. 2. Encouraging coughing and deep breathing helps prevent atelectasis and pneumonia. 3. It promotes lung expansion and clears secretions. 4. This intervention supports respiratory function and aids in recovery. Summary of why the other choices are incorrect: A. Monitoring fluctuations in the water-seal chamber (Choice A) is important for assessing the status of the chest tube drainage, but not the immediate priority for patient care post-pneumonectomy. B. Clamping the chest tube once every shift (Choice B) is not recommended as it can lead to complications like tension pneumothorax. D. Milking the chest tube every 2 hours (Choice D) is unnecessary and can cause trauma to the lung tissue and increase the risk of infection.