The nurse is caring for a patient who underwent pituitary surgery 12 hours ago. The nurse will give priority to monitoring the patient carefully for which of the following?

Correct Answer: B

Rationale: The correct answer is B: Hypovolemic shock. After pituitary surgery, patients are at risk for hypovolemic shock due to potential intraoperative blood loss and fluid shifts. Monitoring for signs of shock, such as hypotension and tachycardia, is crucial for early intervention. A: Congestive heart failure is less likely immediately post-surgery. C: Infection is a concern but not the highest priority in the immediate postoperative period. D: Volume overload is not a common immediate complication of pituitary surgery.

Correct Answer: A

Rationale: The correct answer is A because renin activates the renin-angiotensin-aldosterone cascade. Renin is released by the kidneys in response to low blood pressure or low sodium levels. It acts on angiotensinogen to form angiotensin I, which is then converted to angiotensin II by angiotensin-converting enzyme. Angiotensin II causes vasoconstriction, leading to increased blood pressure, and stimulates aldosterone release, promoting sodium and water retention. Choice B is incorrect because renin does not suppress angiotensin production; it actually initiates the process. Choice C is incorrect because renin's action leads to increased sodium reabsorption by stimulating aldosterone release. Choice D is incorrect because renin does not inhibit aldosterone release; it promotes it as part of the renin-angiotensin-aldosterone cascade.

Correct Answer: D

Rationale: The correct answer is D because if a reliable 24-hour urine collection is not possible, a standardized formula can be used to estimate the GFR. This is typically done using the patient's serum creatinine level, age, sex, and race. It is a validated method when direct measurement is not feasible. A: Incorrect. It is still possible to estimate GFR using formulas when 24-hour urine collection is not possible. B: Incorrect. BUN alone is not sufficient to accurately determine renal function. C: Incorrect. BUN/Creatinine ratio is not a direct measure of GFR and may be influenced by other factors.

Correct Answer: C

Rationale: The correct answer is C: notify the provider immediately. Lack of bruit, thrill, and distal pulse indicates potential complications like thrombosis or occlusion in the arteriovenous fistula. Prompt provider notification is crucial for timely intervention to prevent further complications such as ischemia or access failure. Reassessing the patient in an hour (A) may delay necessary intervention. Raising the arm above the level of the patient's heart (B) does not address the underlying issue. Applying warm packs (D) could worsen the situation if there is a clot present.

Correct Answer: B

Rationale: The correct answer is B: evaluate the patient for signs and symptoms of infection. After 5 days, infection risk increases. Signs of infection include fever, redness, swelling, and tenderness at the catheter site. Monitoring for these signs is crucial to prevent complications. A: Routine dialysis catheter change is not indicated after 5 days. C: Teaching long-term use is incorrect as temporary catheters are not meant for extended use. D: Using lumens for fluid administration can increase infection risk and is not recommended.

Correct Answer: D

Rationale: The correct answer is D. Volume replacement and insulin infusion often correct the acidosis in diabetic ketoacidosis (DKA) because volume depletion and insulin deficiency are key factors in its pathophysiology. Volume replacement helps correct dehydration and improve tissue perfusion, while insulin infusion helps lower blood glucose levels and inhibit ketone production, ultimately correcting the acidosis. A is incorrect because serum lactate levels are not typically used to guide insulin administration in DKA. B is incorrect as sodium bicarbonate is not a first-line medication for DKA treatment as it can worsen metabolic acidosis. C is incorrect as the degree of acidosis in DKA is typically assessed through blood gas analysis, not continuous pulse oximetry.

Correct Answer: B

Rationale: The correct answer is B: fluid replacement with 0.45% saline. The patient's symptoms suggest dehydration and hypovolemia, indicated by low blood pressure, elevated heart rate, and lack of urine output. Fluid replacement with isotonic saline would help restore intravascular volume and improve blood pressure. Blood transfusion (A) is not indicated without evidence of significant blood loss. Inotropic agents (C) are used to improve cardiac function, which is not the primary issue in this case. Antiemetics (D) may help with nausea and vomiting but do not address the underlying cause of hypovolemia.

Correct Answer: B

Rationale: The correct answer is B: deficiency of corticosteroids. Acute adrenal crisis is caused by a sudden and severe deficiency of cortisol and aldosterone, which are essential corticosteroids produced by the adrenal glands. Without these hormones, the body cannot regulate blood pressure, electrolyte balance, and respond to stress adequately. Acute renal failure (choice A) does not directly lead to adrenal crisis. High doses of corticosteroids (choice C) can suppress the adrenal glands but do not cause acute adrenal crisis. Overdose of testosterone (choice D) does not impact the production of cortisol and aldosterone, thus not causing acute adrenal crisis.

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.