Correct Answer: A

Rationale: The correct answer is A: Blood pressure. When a client is on dobutamine, it is crucial to closely monitor their blood pressure as dobutamine can cause significant changes in blood pressure. While heart rate is also important to monitor during this time, blood pressure is the most critical parameter to assess. Oxygen saturation and respiratory rate are also important parameters to monitor in a patient receiving dobutamine, but they are not as crucial as blood pressure in this scenario.

Correct Answer: A

Rationale: The correct answer is AV node. The AV node is responsible for delaying the impulse from the SA node, allowing the atria to contract before the ventricles. This delay ensures the effective pumping of blood in a coordinated manner. Choices B, C, and D are incorrect because the Bundle of His is responsible for transmitting the impulse to the Purkinje fibers, the SA node is the pacemaker of the heart responsible for initiating the heartbeat, and the aorta is the main artery carrying oxygenated blood from the heart to the body, respectively, none of which are involved in delaying the impulse to allow atrial contraction before ventricular contraction.

Correct Answer: A

Rationale: The correct answer is A: Platelet count. When a client is on enoxaparin (Lovenox), monitoring the platelet count is crucial as enoxaparin can lead to a rare but serious side effect known as heparin-induced thrombocytopenia (HIT), causing a decrease in platelet count. Monitoring the platelet count helps detect this adverse reaction early. Choices B, C, and D are incorrect because enoxaparin therapy does not directly affect PT/INR, aPTT, or hemoglobin levels.

Correct Answer: A

Rationale: The correct answer is Aortic dissection. Aortic dissection is a life-threatening condition where the inner layer of the aorta tears, causing severe chest or back pain and internal bleeding, requiring immediate medical attention. Choice B, aneurysm, involves a bulging or weakening of a blood vessel wall, which is different from a tear in the aorta. Choices C and D, stroke and myocardial infarction, do not directly involve the tearing of the aorta and are distinct conditions.

Correct Answer: A

Rationale: The correct answer is A, restrictive cardiomyopathy. This condition specifically involves the stiffening of the heart muscle, leading to a reduced ability to relax and fill with blood between beats. Choice B, hypertrophic cardiomyopathy, is characterized by abnormal thickening of the heart muscle, not stiffening. Choice C, dilated cardiomyopathy, involves the enlargement and weakening of the heart chambers, not stiffening. Choice D, ventricular hypertrophy, refers to the thickening of the walls of the heart's pumping chambers but does not specifically involve the stiffening that is characteristic of restrictive cardiomyopathy.