Correct Answer: C

Rationale: The normal WBC count indicates that the antibiotics have been effective. All the other data suggest that a change in treatment is needed.

Correct Answer: A

Rationale: When caring for a patient with severe mitral regurgitation and decreased cardiac output, assessing for mental status changes is crucial. Decreased cardiac output can lead to inadequate perfusion and oxygenation of vital organs, including the brain, resulting in hypoxia. This hypoxia can manifest as mental status changes such as confusion, restlessness, or lethargy. Therefore, monitoring mental status helps in identifying potential hypoxic states and guiding appropriate interventions. The other options are incorrect as they do not directly correlate decreased cardiac output with potential hypoxia-induced mental status changes.

Correct Answer: D

Rationale: The correct answer is D: Three sputum smears for acid-fast bacilli are negative. Negative sputum smears indicate that Mycobacterium tuberculosis is not present in the sputum, and the patient cannot transmit the bacteria by the airborne route. This finding is crucial for discontinuing airborne precautions. Choice A is incorrect because chest x-rays do not determine the presence of active TB for transmission precautions. Choice B is not directly related to the infectiousness of TB; completing a 6-month course of medication is important for treatment but does not confirm the absence of active disease or infectiousness. Choice C is not relevant to assessing infectiousness; Mantoux testing measures exposure to TB but does not confirm the absence of active infection or infectiousness.

Correct Answer: A

Rationale: For diagnosing pulmonary emboli, spiral computed tomography (CT) scans are commonly used, and contrast media may be given intravenously (IV) during the scan to enhance visualization of blood vessels. Chest x-rays are not typically diagnostic for pulmonary embolism. When preparing for a chest x-ray, the patient needs to undress and remove any metal objects. Bronchoscopy is used for examining the bronchial tree, not for assessing vascular changes, and the patient should be NPO 6 to 12 hours before the procedure. Positron emission tomography (PET) scans are primarily used to detect malignancies, and a radioactive glucose preparation is utilized for this purpose.

Correct Answer: A

Rationale: To evaluate the effectiveness of therapies for cor pulmonale and right-sided heart failure, observing for distended neck veins would be the most appropriate assessment. Cor pulmonale is characterized by right ventricular failure due to pulmonary hypertension, leading to clinical manifestations such as peripheral edema, jugular venous distention, and right upper-quadrant abdominal tenderness. These signs indicate increased central venous pressure and right heart strain, which can be assessed by observing for distended neck veins. Auscultating for crackles in the lungs is more indicative of left-sided heart failure rather than right-sided heart failure. Heaves or thrills over the heart are not typically associated with cor pulmonale. Reviewing hemoglobin and hematocrit values may show elevations due to chronic hypoxemia and polycythemia in cor pulmonale, but these values alone do not directly evaluate the immediate effectiveness of the prescribed therapies on the patient's condition.