Continuous venovenous hemofiltration is used to

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: 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: 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: C

Rationale: The correct answer is C (10 to 20 mg/dL). In conditions where the serum creatinine level is elevated (7 mg/dL in this case), the BUN level is expected to also be elevated due to impaired kidney function. BUN levels are typically around 10-20 mg/dL, so this range is the most appropriate given the elevated creatinine level. Choice A (1 to 2 mg/dL) is too low and would not be expected with a creatinine level of 7 mg/dL. Choice B (7 to 14 mg/dL) is a bit low for such a high creatinine level. Choice D (20 to 30 mg/dL) is too high as it exceeds the typical range for BUN levels. Therefore, choice C is the most appropriate range based on the given information.

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.

Correct Answer: B

Rationale: The correct answer is B: azotemia. Azotemia refers to elevated levels of nitrogenous waste products like BUN and creatinine in the blood. This occurs when the kidneys are not functioning properly, leading to decreased filtration and excretion of waste products. Oliguria (A) is reduced urine output, not specific to elevated BUN and creatinine levels. Acute kidney injury (C) is a broader term for sudden loss of kidney function. Prerenal disease (D) typically refers to conditions affecting blood flow to the kidneys, leading to decreased kidney function, but it does not specifically describe the increase in BUN and creatinine levels.

Correct Answer: C

Rationale: The correct answer is C: intrarenal disease, probably acute tubular necrosis. The presence of coarse, muddy brown granular casts and hematuria in the urinalysis indicates damage to the renal tubules, which is characteristic of acute tubular necrosis. This condition is a type of intrarenal disease where there is direct damage to the kidney tubules, leading to decreased urinary output and symptoms like malaise and fatigue. Prerenal and postrenal conditions do not typically present with granular casts and hematuria, making choices A and B incorrect. Urinary tract infection is also unlikely to cause the specific findings seen in this case, ruling out choice D. Therefore, choice C is the most appropriate based on the urinalysis results and clinical presentation.

Correct Answer: A

Rationale: The correct answer is A (Blood glucose >1000 mg/dL) because diabetic ketoacidosis is characterized by severe hyperglycemia. High blood glucose levels (>1000 mg/dL) are common due to insulin deficiency leading to increased glucose production. B: Negative ketones in the urine would be incorrect as DKA results in ketone production, leading to ketonuria. C: Normal anion gap would be incorrect as DKA typically presents with an elevated anion gap metabolic acidosis due to ketone accumulation. D: pH 7.24 would be incorrect as DKA would present with a lower pH due to metabolic acidosis.