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: C

Rationale: In a patient with metabolic alkalosis and an O2 saturation of 94%, placing the patient on high-flow oxygen is the correct action. Even though the O2 saturation seems adequate, metabolic alkalosis causes a left shift in the oxyhemoglobin dissociation curve, reducing oxygen delivery to tissues. Therefore, providing high-flow oxygen can help compensate for this. Administering bicarbonate would exacerbate the alkalosis. While completing a head-to-toe assessment and obtaining repeat ABGs are important interventions, the priority in this scenario is to improve oxygen delivery by placing the patient on high-flow oxygen.

Correct Answer: B

Rationale: Kussmaul respirations (deep and rapid) are a compensatory mechanism for metabolic acidosis. The low pH and low bicarbonate levels indicate metabolic acidosis. Intercostal retractions, low oxygen saturation, and decreased venous O2 pressure are not associated with acidosis. Intercostal retractions typically occur in respiratory distress, while low oxygen saturation and decreased venous O2 pressure are more related to respiratory or circulatory issues, not metabolic acidosis.

Correct Answer: B

Rationale: For a 40-year-old patient with multiple sclerosis experiencing urinary retention due to a flaccid bladder, teaching the Cred method is the appropriate action. The Cred method involves applying manual pressure over the bladder to aid in bladder emptying. Decreasing fluid intake is not the correct approach as it will not address the underlying issue of bladder emptying and may lead to dehydration and urinary tract infections. Using adult incontinence briefs only addresses the symptom of incontinence without addressing the bladder emptying problem. Assisting the patient to the commode every 2 hours does not actively address the issue of improving bladder emptying as effectively as teaching the Cred method.

Correct Answer: D

Rationale: The patient presents with symptoms indicative of a pulmonary embolism (PE), such as chest pain, difficulty breathing, tachycardia, hypotension, and tachypnea. Elevating the head of the bed to a semi-Fowler's position is the priority to improve ventilation and gas exchange. This intervention should be initiated promptly to optimize oxygenation. Subsequent actions, such as notifying the healthcare provider, preparing for a spiral CT scan, and administering anticoagulant therapy, can follow after the patient's position is adjusted. The spiral CT scan is typically used to confirm the diagnosis of PE, and anticoagulant therapy is initiated upon confirmation of the diagnosis by the healthcare provider. Therefore, the immediate focus is on improving the patient's respiratory status by elevating the head of the bed.