Correct Answer: C

Rationale: Rationale: Acute tubular necrosis (ATN) is the most common intrarenal condition causing acute kidney injury. ATN is characterized by damage to the renal tubules due to ischemia or nephrotoxic substances. Prolonged ischemia (choice A) and exposure to nephrotoxic substances (choice B) can lead to ATN. Hypotension for several hours (choice D) can result in ischemic injury, which may lead to ATN but is not the direct cause. Therefore, choice C is correct as it directly relates to the primary intrarenal condition of ATN.

Correct Answer: D

Rationale: The correct answer is D: Discontinue the IV infusion and administer the Lantus insulin at bedtime. This is the correct approach because insulin glargine (Lantus) is a long-acting basal insulin that provides a steady level of insulin throughout the day and night. By administering it at bedtime, it mimics the basal insulin secretion in a person without diabetes. This helps maintain stable blood sugar levels overnight. Choice A is incorrect because continuing the IV insulin infusion for 24 hours alongside insulin glargine is unnecessary and may lead to insulin overdose. Choice B is incorrect because discontinuing the IV infusion in several hours without administering the long-acting insulin can lead to inadequate insulin coverage. Choice C is incorrect because insulin aspart is a rapid-acting insulin that should be given with meals, not as a basal insulin replacement at bedtime.

Correct Answer: B

Rationale: The correct answer is B: prepare for intubation and mechanical ventilation. The patient's arterial blood gas results indicate metabolic acidosis (low pH, low bicarbonate) with respiratory compensation (low PCO). In this scenario, the patient is likely experiencing respiratory fatigue due to tachypnea from metabolic acidosis. Intubation and mechanical ventilation are needed to support the patient's respiratory effort and correct the acid-base imbalance. Administering morphine (choice A) can further depress the respiratory drive. Administering intravenous sodium bicarbonate (choice C) can temporarily correct the pH but does not address the underlying respiratory distress. Canceling dialysis (choice D) is not indicated as it does not address the acute respiratory compromise.

Correct Answer: D

Rationale: The correct answer is D because the presence of red blood cells and albumin in the urine indicates kidney damage, as these are not normally found in urine. A: Creatinine levels should be similar in blood and urine for proper kidney function. B: Sodium and chloride are normal components of urine. C: Uric acid levels can vary in urine and serum. Therefore, D is the correct answer as it signals potential kidney injury.

Correct Answer: D

Rationale: The correct answer is D because continuous venovenous hemodiafiltration (CVVHDF) combines ultrafiltration, convection, and dialysis to maximize fluid and solute removal. Ultrafiltration removes plasma water, convection removes fluids and solutes, and dialysis facilitates solute removal through diffusion. Choice A is incorrect because convection alone does not remove solutes, but CVVHDF combines convection with other methods. Choice B is incorrect because CVVHDF is not specifically used for volume overload, although it does remove fluids. Choice C is incorrect because CVVHDF does not involve adding dialysate to remove solutes; instead, it relies on diffusion for solute removal. In summary, the correct answer D is the best choice as it encompasses all the components needed for comprehensive fluid and solute removal in CVVHDF.