Correct Answer: A

Rationale: The correct answer is A: administration of a 1-L normal saline fluid bolus. In this scenario, the patient is likely experiencing diabetic ketoacidosis (DKA) due to the extremely high glucose levels, low bicarbonate, and anion gap metabolic acidosis. The priority is to correct the dehydration and electrolyte imbalances through fluid resuscitation with normal saline to improve perfusion and reverse the metabolic derangements. Options B, C, and D do not address the immediate need for volume resuscitation and correction of dehydration. Administering insulin or potassium without first addressing the fluid deficit could lead to further complications. Sodium bicarbonate is not recommended in DKA as it can worsen acidosis and has not been shown to improve outcomes.

Correct Answer: A

Rationale: The correct answer is A because acute kidney injury from postrenal etiology is caused by obstruction of the flow of urine, leading to back pressure and damage to the kidneys. Choices B and C relate to prerenal causes, affecting renal perfusion and volume status. Choice D refers to intrinsic renal causes, directly affecting kidney tissue function, not postrenal obstruction. Therefore, A is correct due to the nature of postrenal etiology.

Correct Answer: A

Rationale: The correct answer is A: Decreased reflexes. In myxedema coma, a severe form of hypothyroidism, patients often present with decreased mental status, hypothermia, and bradycardia. Decreased reflexes are a common neurological manifestation due to the slowing of metabolic processes and the central nervous system depression associated with this condition. Hyperthermia (B) is not typically seen in myxedema coma, as patients usually have low body temperature. Hyperventilation (C) is also unlikely, as respiratory depression is more common. Tachycardia (D) is incorrect because bradycardia is more characteristic of myxedema coma.

Correct Answer: D

Rationale: In hyperosmolar hyperglycemic syndrome, patients have high blood glucose levels, leading to dehydration and increased serum osmolality. Unlike diabetic ketoacidosis, there is no significant ketosis in hyperosmolar hyperglycemic syndrome. Therefore, the correct answer is D: Higher serum glucose, higher osmolality, and no ketosis. A: Lower serum glucose, lower osmolality, and greater ketosis - This is incorrect because hyperosmolar hyperglycemic syndrome is characterized by high blood glucose levels and no significant ketosis. B: Lower serum glucose, lower osmolality, and milder ketosis - This is incorrect because hyperosmolar hyperglycemic syndrome presents with higher glucose levels and no ketosis. C: Higher serum glucose, higher osmolality, and greater ketosis - This is incorrect because hyperosmolar hyperglycemic syndrome does not typically involve significant ketosis.

Correct Answer: A

Rationale: The correct answer is A: Sodium polystyrene sulfonate. It works by exchanging sodium ions for potassium ions in the colon, leading to potassium excretion. A is the safest option without the risk of causing hypernatremia or intestinal necrosis like B. Regular insulin (C) may cause hypoglycemia and is not as effective as A in reducing potassium levels. Calcium gluconate (D) does not directly reduce potassium levels and is used for treating hyperkalemia-related cardiac toxicity.