Correct Answer: A

Rationale: The correct answer is A because continuous venovenous hemofiltration primarily removes fluids and solutes through convection. Convection involves the movement of solutes across a semi-permeable membrane by the force of the fluid flow. This process helps to achieve fluid balance and manage electrolyte levels in patients with renal failure. Choice B is incorrect because hemofiltration does not specifically target plasma water; it aims to remove both fluids and solutes. Choice C is incorrect as hemofiltration does not involve adding dialysate; it relies on the patient's blood passing through a filter to remove waste products. Choice D is incorrect because while hemofiltration may involve aspects of ultrafiltration and dialysis, the primary mechanism is convection for removing fluids and solutes.

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: B

Rationale: The correct answer is B because renal dysfunction is a common issue in critically ill patients due to factors like sepsis or hypoperfusion. This affects nearly two thirds of patients, leading to potential complications. Choice A is incorrect as renal dysfunction is common, not rare. Choice C is incorrect as mortality rates can still be high even with renal replacement therapy. Choice D is incorrect as renal dysfunction can significantly impact morbidity, mortality, and quality of life in critically ill patients.

Correct Answer: A

Rationale: The correct answer is A: fluid retention of 1.5 liters. The weight gain from 5 kg to 99 kg indicates an increase of 94 kg. Since 1 kg of weight gain is approximately equal to 1 liter of fluid retention, the patient has retained 94 liters of fluid. Therefore, the correct choice is fluid retention of 1.5 liters. Choice B is incorrect because the weight gain indicates fluid retention, not loss. Choice C is incorrect as it mentions equal intake and output, which does not match the weight gain observed. Choice D is incorrect as it suggests fluid loss, which contradicts the weight gain.

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.