Correct Answer: A

Rationale: The correct answer is A: Platelet count. When administering enoxaparin (Lovenox) for DVT prophylaxis, it is crucial to monitor the platelet count as enoxaparin can lead to thrombocytopenia, a decrease in platelet levels. Monitoring the platelet count helps in early detection of this potential adverse effect. Choices B, C, and D are incorrect because PT/INR, aPTT, and hemoglobin levels are not the most important lab values to monitor specifically for enoxaparin administration and DVT prophylaxis.

Correct Answer: B

Rationale: In cases of myocardial infarction leading to shock, dopamine is the drug of choice. Dopamine helps increase blood pressure and improve blood flow to vital organs, making it beneficial in managing shock. Atropine is mainly used for symptomatic bradycardia, not for shock. Digoxin is a cardiac glycoside used in heart failure and atrial fibrillation, not for managing shock. Adenosine is typically used for diagnosing and treating supraventricular tachycardias, not for shock associated with myocardial infarction.

Correct Answer: A

Rationale: Pneumothorax is the correct answer for this question. Pneumothorax is the collapse of a lung caused by the presence of air in the pleural space between the lung and chest wall. This condition can lead to chest pain, shortness of breath, and may require emergency treatment such as chest tube insertion to remove the air. Pleural effusion is the accumulation of fluid in the pleural space, not air. Atelectasis is the collapse or closure of a lung resulting in reduced or absent gas exchange. Pulmonary fibrosis is a condition characterized by scarring and thickening of lung tissue, not related to air leaking into the pleural space.

Correct Answer: A

Rationale: Pleural effusion is the correct answer as it refers to the accumulation of excess fluid between the layers of the pleura surrounding the lungs and chest cavity. This condition can be caused by various factors such as infections, heart failure, or cancer. Pulmonary edema (choice B) involves fluid accumulation in the lungs' air sacs and is not specific to the pleura. Atelectasis (choice C) is the collapse or closure of a lung leading to airless lung tissue and is not related to fluid buildup. Sarcoidosis (choice D) is a condition characterized by the growth of tiny collections of inflammatory cells in different parts of the body, not specifically involving fluid accumulation in the pleural space.

Correct Answer: A

Rationale: The correct answer is to hold the digoxin and notify the healthcare provider. A potassium level of 2.8 mEq/L indicates hypokalemia, which can increase the risk of digoxin toxicity. Holding the medication and informing the healthcare provider is crucial to prevent adverse effects. Choice B is incorrect because increasing the dose of digoxin would further raise the risk of toxicity. Choice C is incorrect as continuing the current dose could exacerbate the toxicity risk. Choice D is incorrect because administering potassium supplements alone is not sufficient to address the potential digoxin toxicity; the first step should be to hold the digoxin and seek further guidance.