Correct Answer: D

Rationale: The correct answer is D, Left ventricle. The left ventricle pumps oxygenated blood into the systemic circulation via the aorta. This chamber receives oxygen-rich blood from the left atrium and contracts forcefully to propel blood into the aorta, distributing it to the body. The other options, right atrium, left atrium, and right ventricle, do not directly eject blood into the systemic arterial circulation via the aorta. The right atrium receives deoxygenated blood from the body, the left atrium receives oxygenated blood from the lungs, and the right ventricle pumps blood to the lungs for oxygenation.

Correct Answer: A

Rationale: The correct answer is to hold the beta blocker and notify the healthcare provider. A blood pressure of 90/60 mm Hg is already low, and beta blockers can further decrease blood pressure. Administering the beta blocker can potentially worsen the situation, leading to complications. Administering a diuretic or continuing to monitor the client without taking immediate action could delay necessary intervention. Therefore, holding the beta blocker and involving the healthcare provider promptly is crucial in this scenario.

Correct Answer: A

Rationale: An INR of 4.5 is elevated, indicating an increased risk of bleeding due to excessive anticoagulation. The most appropriate action for the nurse in this scenario is to administer vitamin K. Vitamin K helps reverse the anticoagulant effects of warfarin, thus lowering the INR and reducing the risk of bleeding. Holding the next dose of warfarin (choice B) is not sufficient to address the immediate high INR level. Increasing the dose of warfarin (choice C) would further elevate the INR, worsening the risk of bleeding. While monitoring the client's INR closely (choice D) is important, immediate action is required to address the critically high INR level, making the administration of vitamin K the priority intervention.

Correct Answer: A

Rationale: A stroke is the correct answer. A stroke occurs when the blood supply to part of the brain is interrupted or reduced, leading to a lack of oxygen and nutrients to the brain tissue, causing brain damage. Choices B, C, and D are incorrect because a transient ischemic attack (TIA) is a temporary blockage of blood flow to the brain with no lasting damage, myocardial infarction is a heart attack due to blockage of blood flow to the heart muscle, and angina is chest pain caused by reduced blood flow to the heart.

Correct Answer: A

Rationale: When giving dobutamine, the most critical parameter to assess is blood pressure. Dobutamine is known to cause significant changes in blood pressure, making it essential to closely monitor this parameter to prevent adverse effects. While heart rate is also important to monitor, blood pressure takes precedence due to the potential for hemodynamic instability caused by dobutamine. Oxygen saturation and respiratory rate, although vital signs to monitor, are not typically affected directly by dobutamine administration.