Your pediatric patient has been ill for several days leading you to suspect he may be dehydrated. Once on the electrocardiogram, it is evident the patient has an accelerated heart rate and abnormally flattened T waves. What is the most likely cause of this finding?

Correct Answer: D

Rationale: The correct answer is D: Hypokalemia. Hypokalemia, or low potassium levels, can lead to an accelerated heart rate and flattened T waves on an ECG. Potassium plays a crucial role in maintaining the electrical activity of the heart. Low potassium levels can disrupt the balance of ions in cardiac cells, leading to abnormal heart rhythms and ECG changes. Hyperglycemia (choice A) and hypoglycemia (choice C) typically do not cause ECG changes like flattened T waves. Hyperkalemia (choice B) would lead to peaked T waves rather than flattened T waves on an ECG.

Correct Answer: C

Rationale: The correct answer is C because lactated Ringer's contains lactate, which is converted to bicarbonate in the body, helping to decrease acidosis in a hypovolemic patient. Normal saline does not have this buffering effect. A is incorrect because both solutions stay in the vascular system similarly. B is incorrect as neither solution carries red blood cells. D is incorrect as lactated Ringer's does not increase acidosis but helps decrease it.

Correct Answer: A

Rationale: The correct answer is A: Monro-Kellie Principle. This principle states that the total intracranial volume is constant, and an increase in one component (e.g., blood, CSF, brain tissue) must be compensated by a decrease in another to maintain a stable intracranial pressure (ICP). This helps to prevent dangerous elevations in ICP, which is crucial in managing head injuries. B: Bernicke Principle is not relevant to intracranial pressure regulation. C: Fick Principle is related to cardiac output and oxygen consumption, not intracranial pressure. D: Bernoulli's Principle is about fluid dynamics, not intracranial pressure regulation.

Correct Answer: B

Rationale: The correct answer is B: To ensure any undeployed airbags do not discharge and cause an injury to the patient or anyone involved. When a vehicle's battery is not disconnected before attempting to enter or extricate a driver, there is a risk that any undeployed airbags may still be active and could suddenly inflate, potentially causing harm to the patient or anyone involved in the extrication process. Disconnecting the battery eliminates the power source for the airbags, reducing the risk of unintended deployment. Choice A is incorrect because disconnecting the battery is not primarily done to prevent the vehicle from moving during extrication; other safety measures are in place for that purpose. Choice C is incorrect as the risk of electrocution is minimal if proper extrication procedures are followed. Choice D is incorrect because while a fire is a concern in vehicle accidents, disconnecting the battery is not specifically related to preventing fires in the passenger compartment during extrication.

Correct Answer: D

Rationale: Step-by-step rationale for why option D is correct: 1. Triage aims to maximize survivors with available resources. 2. Option D prioritizes producing the greatest number of survivors. 3. It aligns with the principle of maximizing outcomes in mass casualty situations. 4. Focusing on maximizing survivors helps allocate resources efficiently. 5. Options A, B, and C are incorrect as they do not prioritize maximizing survivors and efficient resource utilization.