Correct Answer: A

Rationale: Flattened T waves are an early ECG sign of hyperkalemia. Hyperkalemia affects the repolarization phase of the cardiac action potential, leading to changes such as peaked T waves, prolonged PR interval, widened QRS complex, and ultimately sine wave pattern. Elevated ST segments, prominent U waves, and widened QRS complex are not typically associated with hyperkalemia, making choices B, C, and D incorrect.

Correct Answer: A

Rationale: Flattened T waves are an early ECG sign of hyperkalemia. Hyperkalemia affects the repolarization phase of the cardiac action potential, leading to changes such as peaked T waves, prolonged PR interval, widened QRS complex, and ultimately sine wave pattern. Elevated ST segments, prominent U waves, and widened QRS complex are not typically associated with hyperkalemia, making choices B, C, and D incorrect.

Correct Answer: A

Rationale: Flattened T waves are an early sign of hypokalemia on an ECG. In hypokalemia, the T waves may flatten and eventually invert. Elevated ST segments are not typically associated with hypokalemia. Prominent U waves are seen in conditions like hypokalemia, but they are not considered an early sign. A widened QRS complex is more commonly associated with hyperkalemia rather than hypokalemia.

Correct Answer: A

Rationale: In hypokalemia, flattened T waves are a common ECG finding due to the decreased extracellular potassium affecting repolarization. Prominent U waves are typically seen in hypokalemia as well, but flattened T waves are the more specific and early ECG change. Widened QRS complexes are associated with hyperkalemia, not hypokalemia. ST elevation is often seen in conditions like myocardial infarction, pericarditis, or early repolarization syndrome, not specifically in hypokalemia.

Correct Answer: A

Rationale: The correct answer is Albuterol 3 ml via nebulizer. Albuterol is a bronchodilator that helps relieve wheezing and coughing by opening up the airways, making it the first-line treatment for allergic reactions presenting with these symptoms. Cromolyn and aminophylline are not typically used as first-line treatments for acute allergic reactions with wheezing and coughing. Methylprednisolone, a corticosteroid, may be beneficial for inflammation in the setting of an allergic reaction but is not the initial medication of choice to address wheezing and coughing.