The critical care nurse knows that in critically ill patients, renal dysfunction

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: 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 (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.

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: 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 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: 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.

Correct Answer: C

Rationale: The correct answer is C, Serum sodium 115 mEq/L. In syndrome of inappropriate secretion of antidiuretic hormone (SIADH), there is excess release of ADH leading to water retention and dilutional hyponatremia. Low serum sodium levels (hyponatremia) are characteristic of SIADH due to water retention without proportional sodium retention. Choices A and B are not indicative of SIADH. Choice D, high serum sodium, is more likely in conditions causing dehydration or excessive sodium intake.