Cardiovascular System Exam

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: A

Rationale: Bradycardia is the correct answer. It is a condition characterized by a slow heart rate, which reduces the amount of blood pumped to the body. This can lead to symptoms like fatigue and dizziness. Choice B, Tachycardia, is the opposite condition where the heart beats too fast. Choices C and D, Atrial fibrillation and Ventricular fibrillation, refer to irregular and potentially life-threatening rapid heart rhythms involving the atria and ventricles respectively, not a slow heart rate.

Correct Answer: A

Rationale: The correct answer is Purkinje fibers. Purkinje fibers are specialized conducting fibers that distribute the electrical impulse to the ventricles, leading to their contraction. The SA node (sinoatrial node) is responsible for initiating the electrical impulse in the heart, the AV node (atrioventricular node) delays the impulse to allow for proper atrial contraction before ventricular contraction, and the Bundle of His transmits the impulse from the AV node to the ventricles. Therefore, choices B, C, and D are not the correct options for fibers directly distributing the impulse to the ventricles.

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.

Correct Answer: A

Rationale: The correct answer is A, cystic fibrosis. Cystic fibrosis is a genetic disorder that primarily affects the lungs and digestive system. It leads to the production of thick, sticky mucus that can clog the airways, causing respiratory issues. Choice B, COPD (Chronic Obstructive Pulmonary Disease), is a different condition usually caused by smoking or exposure to irritants. Choice C, bronchiectasis, involves the widening and scarring of the airways, not the production of thick mucus. Choice D, pulmonary fibrosis, is a lung disease characterized by scarring of the lung tissue, not excessive mucus production.