Mechanisms for development of diabetes insipidus include which of the following? (Select all that apply.)

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: B

Rationale: The correct answer is B because peritoneal dialysis uses the patient's own semipermeable membrane, the peritoneal membrane, to filter waste and excess fluid from the blood. This membrane allows for the exchange of fluids and solutes, making it an effective method for dialysis. A is incorrect because peritoneal dialysis can be used for acute kidney injury. C is incorrect as peritoneal dialysis can address drug overdose and electrolyte imbalance by removing toxins and balancing electrolytes. D is incorrect as peritoneal dialysis can be used in cases of water intoxication by helping to remove excess fluid from the body.

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: 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: Heredity. Nephrogenic diabetes insipidus can be inherited as a genetic condition. The mutation in genes responsible for regulating water balance in the kidneys can lead to this disorder. Other choices are incorrect: B: Medications like lithium can cause acquired nephrogenic diabetes insipidus, not its development. C: Meningitis is an inflammatory condition that does not directly relate to nephrogenic diabetes insipidus. D: Pituitary tumors are associated with central diabetes insipidus, not nephrogenic.

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: 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: 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: D

Rationale: Correct Answer: D Rationale: In diabetic emergencies, starting IV dextrose at 250 mg/dL prevents hypoglycemia while resolving ketoacidosis. Below 250 mg/dL, the body can use endogenous glucose, so IV dextrose is not necessary. Summary: A: Incorrect. Normal saline may be used for initial fluid resuscitation but does not address the need for glucose. B: Incorrect. Starting dextrose at 70 mg/dL may lead to unnecessary hyperglycemia and complications. C: Incorrect. Waiting until 150 mg/dL delays the provision of necessary glucose for metabolic functions.