The nurse has admitted a client to the emergency room with complaints of chest pain over the previous 2 hours. There are no clear changes on the 12-lead. The nurse would expect which laboratory test to provide confirmation of a myocardial infarction (MI)?

Correct Answer: C

Rationale: The correct answer is C: CK of 320 with MB of 12%. Creatinine kinase (CK) is an enzyme released into the bloodstream when muscle cells, including heart muscle cells, are damaged. The MB fraction specifically indicates cardiac muscle damage. A CK level of 320 with an MB percentage of 12% is indicative of myocardial infarction (MI). This combination of values provides confirmation of cardiac muscle damage and points towards an MI diagnosis. Choice A: Potassium level is not specific to MI diagnosis. Choice B: CK level of 545 with MB of 4% is lower than the correct answer, which indicates less cardiac muscle damage. Choice D: WBC count is not specific to MI and indicates inflammation or infection rather than cardiac muscle damage.

Correct Answer: A

Rationale: The correct answer is A: Weakness and pain in legs. In a child with coarctation of the aorta, there is a narrowing of the aorta which can lead to decreased blood flow to the lower extremities. This can result in symptoms such as weakness and pain in the legs, especially during physical activity like recess. By questioning the child about these symptoms, the nurse can assess the severity of the condition and determine the need for further evaluation or intervention. Choices B, C, and D are incorrect because blurred vision, increased respiratory rate, and bruises on shins are not typically associated with coarctation of the aorta. These symptoms may indicate other health issues but are not directly related to the condition in this case.

Correct Answer: C

Rationale: The correct answer is C because an ST segment myocardial infarction signifies a full-thickness heart attack causing death of heart muscle through all three layers. This type of MI is serious and can lead to significant complications. Explanation for why other choices are incorrect: A: This answer is incorrect because the permanency of changes on the ECG does not fully explain the severity or extent of the heart attack. B: This answer is incorrect because describing a smaller MI that only affects part of the heart wall does not accurately represent an ST segment myocardial infarction. D: This answer is incorrect because it confuses the absence of elevated cardiac markers with the severity of the heart attack, which is not a reliable indicator of the extent of damage in an ST segment myocardial infarction.

Correct Answer: A

Rationale: The correct answer is A: Transcutaneous pacer. In an emergency, a transcutaneous pacer is used as it can be quickly attached by the critical care nurse externally to provide temporary pacing. Other options are not typically used in emergencies: B) Epicardial pacer requires surgical placement, C) Transvenous pacer is inserted via a vein and takes longer to set up, and D) Permanent pacer is surgically implanted for long-term pacing needs. Therefore, A is the most suitable choice for immediate intervention in critical situations.

Correct Answer: C

Rationale: The correct answer is C because low potassium levels can increase the risk of digoxin toxicity. By checking the digoxin level, the nurse can ensure the patient's safety and prevent potential complications. Option A is incorrect as monitoring is necessary regardless of the level. Option B is incorrect as administering potassium without assessing the digoxin level can be dangerous. Option D is incorrect as stopping digoxin abruptly can lead to adverse effects. In summary, option C is the most appropriate intervention to ensure patient safety and prevent complications.