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Chapter 28. Renal Diseases

A 69-year-old man with stage III chronic kidney disease undergoes cerebral angiography. Which of the following interventions is most likely to prevent contrast nephropathy?

A. Hypo-osmolar contrast media

B. Fenoldopam infusion

C. Intravenous (IV) hydration with sodium bicarbonate

D. Mannitol infusion

E. Furosemide bolus

C. Patients with preexisting kidney impairment are at increased risk for contrast nephropathy. IV hydration helps to maintain renal perfusion, and sodium bicarbonate further reduces free radical production in the renal medulla, mitigating the effects of the contrast. Use of iso-osmolar contrast media, compared with nonionic hypo-osmolar contrast media, reduces incidence of acute kidney injury (AKI) following administration. Although it increases renal blood flow and creatinine clearance, fenoldopam has not been shown to improve outcomes, and it further predisposes the patient to hypotension and resultant decrease in renal perfusion. Mannitol administration does not significantly reduce the incidence of AKI, whereas furosemide increases the incidence of AKI following contrast administration.

A 74-year-old woman presents to the emergency department (ED) with new-onset hemoptysis and altered mental status. She is emergently intubated and admitted to the intensive care unit (ICU). Chest x-ray shows a speculated mass in the right upper lobe, and initial laboratory evaluation reveals the following values:

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134 mEq/L

Blood urea nitrogen (BUN)

10 mg/dL


4.3 mEq/L


1.0 mg/dL


100 mEq/L


87 mg/dL


23 mEq/L


14.8 mg/dL

What is the most important next step in management?

A. Sodium chloride infusion

B. Pamidronate infusion

C. Calcitonin infusion

D. Intravenous (IV) furosemide bolus

E. Glucocorticoids

A. This woman presents with severe hypercalcemia, which often manifests with altered mental status, gastrointestinal complaints (constipation, anorexia, nausea, vomiting), renal dysfunction, and generalized weakness. Hypercalcemia may be a presenting sign of a number of malignancies including squamous cell carcinomas of the lung, as suggested by her chest x-ray. The most imperative intervention is to treat the accompanying dehydration prior to initiation of a loop diuretic to increase renal calcium clearance. Bisphosphonates and calcitonin may be initiated as a second-line therapy in patients with persistent hypercalcemia once they have undergone aggressive hydration and diuresis. Glucocorticoids may also be given as an adjunctive treatment but are reserved for cases in which an inflammatory condition is suspected, such as granulomatous disease or lymphoma. Hemodialysis is used in patients in whom ...

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