While assessing a critically ill client in the emergency department, the nurse notes on the cardiac monitor an R-on-T premature ventricular beat that develops into ventricular tachycardia (VT). Immediately, the client became unresponsive. The nurse knows that based on pathophysiologic principles, the most likely cause of the unresponsiveness is:

Correct Answer: B

Rationale: The correct answer is B. Ventricular tachycardia (VT) can disrupt the normal heart function, leading to a decreased cardiac output. This decreased output can interrupt the blood supply to the brain, causing the client to become unresponsive. Metabolic acidosis (Choice A) is not the most likely cause of unresponsiveness in this scenario. A massive cerebrovascular accident (CVA) (Choice C) would not result from increased perfusion. A blood clot occluding the carotid arteries (Choice D) may lead to a stroke but is not the most likely cause of sudden unresponsiveness in this situation.

Correct Answer: C

Rationale: Prophylactic antimicrobial therapy before any invasive procedure is the most effective measure in preventing bacterial endocarditis in at-risk individuals. This measure helps to reduce the risk of bacterial infection during invasive procedures, which can lead to endocarditis. Choice A is incorrect as avoiding exposure to individuals with streptococcus does not address the primary preventive measure needed. Choice B is incorrect as corticosteroids do not prevent bacterial endocarditis, and daily administration is not the recommended prophylactic measure. Choice D is incorrect as routine vaccinations against meningococcal and pneumococcal infections are important for other conditions but not specifically for preventing bacterial endocarditis.

Correct Answer: C

Rationale: The correct intervention for a client with ALS is to provide nutritional support to prevent aspiration. ALS causes muscle weakness, including the muscles used for swallowing, increasing the risk of aspiration. Providing proper nutrition and support can help prevent this complication. Administering muscle relaxants (Choice A) may not be suitable for ALS as it can further weaken muscles. While assisting with ADLs (Choice B) and encouraging physical therapy (Choice D) are important aspects of care, the priority for a client with ALS is to prevent complications related to swallowing and nutrition.

Correct Answer: B

Rationale: During a pulmonary exacerbation in cystic fibrosis, the priority intervention is to initiate airway clearance techniques. These techniques help clear mucus from the airways, improving ventilation and reducing the risk of respiratory complications. Administering a high-calorie, high-protein diet is beneficial for overall nutrition but is not the priority during an exacerbation. Encouraging an active lifestyle is important for long-term health but does not address the immediate need for managing exacerbations. Monitoring for signs of respiratory distress is important, but initiating airway clearance techniques takes precedence in the management of pulmonary exacerbations in cystic fibrosis.

Correct Answer: C

Rationale: The correct answer is C: Mitral valve stenosis. Rheumatic fever can lead to scarring and thickening of the heart valves, often affecting the mitral valve. This stenosis can impede blood flow from the left atrium to the left ventricle, eventually causing heart failure. Choice A, infective endocarditis, is an infection of the endocardium, the inner lining of the heart chambers and valves, and is not directly related to rheumatic fever. Choice B, coronary artery disease, involves the obstruction of coronary arteries supplying the heart muscle with blood, leading to ischemia and not typically associated with rheumatic fever. Choice D, aortic regurgitation, is the backflow of blood from the aorta to the left ventricle and is not a common consequence of rheumatic fever.