Correct Answer: A

Rationale: The correct answer is A: ADH deficiency. Diabetes insipidus is caused by a deficiency of antidiuretic hormone (ADH), leading to excessive urine production and thirst. ADH is responsible for regulating water reabsorption in the kidneys. When ADH levels are low or absent, the kidneys cannot concentrate urine effectively, resulting in excessive urine output. Explanation for why other choices are incorrect: B: ADH excess would not lead to diabetes insipidus, as it would result in increased water reabsorption and concentrated urine. C: ADH insensitivity refers to a condition where the body does not respond to ADH, but it does not cause diabetes insipidus. D: ADH replacement therapy is actually a treatment for diabetes insipidus, not a mechanism for its development.

Correct Answer: A

Rationale: The correct answer is A: a percutaneous catheter at the bedside. In this urgent situation, a percutaneous catheter can be quickly inserted at the bedside to provide immediate vascular access for hemodialysis. This option allows for rapid initiation of treatment without the need for surgical placement or waiting for a more permanent access like an arteriovenous fistula or graft. Incorrect Choices: B: A percutaneous tunneled catheter may require more time for insertion due to tunneling and may not be suitable for immediate use. C: An arteriovenous fistula is a more permanent access created surgically and requires time to mature before being used for hemodialysis. D: An arteriovenous graft is also a surgical option that requires time to heal and mature before being used for hemodialysis.

Correct Answer: A

Rationale: The correct answer is A. Bladder catheterization helps relieve urinary obstruction, a common postrenal cause of acute kidney injury. It allows urine to drain freely from the bladder. - B: Increasing fluid volume intake may worsen the condition by increasing the pressure on the obstructed kidneys. - C: Ureteral stenting is used for intrarenal causes, not postrenal causes. - D: Placement of nephrostomy tubes bypasses the obstruction but is usually reserved for more severe cases.

Correct Answer: A

Rationale: The correct answer is A: Atrial fibrillation. In thyroid storm, excess thyroid hormone levels can lead to increased sympathetic activity, causing tachycardia and arrhythmias like atrial fibrillation. Atrial fibrillation is common in thyroid storm due to the hypermetabolic state and increased risk of atrial arrhythmias. Other choices are incorrect: B (Idioventricular rhythm) is not typically associated with thyroid storm, C (Junctional rhythm) is less likely since atrial arrhythmias are more common, and D (Sinus bradycardia) is unlikely due to the hypermetabolic state causing tachycardia.

Correct Answer: A

Rationale: The correct answer is A: Hypotension. Hemodialysis can lead to hypotension due to rapid fluid removal, causing a drop in blood pressure. This occurs as the dialysis machine removes excess fluid, affecting plasma volume. Hypotension can result in complications like dizziness, nausea, and potential cardiac issues. Dysrhythmias (B) are less common during hemodialysis for acute kidney injury. Muscle cramps (C) may occur due to electrolyte imbalances but are not as common as hypotension. Hemolysis (D) is not a common complication of hemodialysis but can occur if there are issues with the dialysis machine or blood tubing.