A 67-year-old woman is evaluated for intermittent claudication prior to angiography. At a recent evaluation, her ankle-brachial index was 0.65 on the right and 0.75 on the left. The patient has a history of long-term cigarette smoking, hypertension, type 2 diabetes mellitus, hyperlipidemia, and severe degenerative arthritis of the knees. Current medications include simvastatin, ibuprofen, glipizide, and amlodipine.
Blood pressure is 130/86 mm Hg and pulse is 72/min. Cardiac examination reveals a grade 2/6 systolic ejection murmur at the base. The lungs are clear and there is no jugular venous distension. Tibial pulses are 1+ and the patient has trace pedal edema of the ankles bilaterally.
Serum creatinine is 2 mg/dL and urinalysis shows 2+ proteinuria.
In addition to using the smallest dose of a third-generation contrast agent and prehydrating with normal saline, which of the following is the most appropriate precaution for this patient's angiography?

Question

A 67-year-old woman is evaluated for intermittent claudication prior to angiography.  At a recent evaluation, her ankle-brachial index was 0.65 on the right and 0.75 on the left.  The patient has a history of long-term cigarette smoking, hypertension, type 2 diabetes mellitus, hyperlipidemia, and severe degenerative arthritis of the knees.  Current medications include simvastatin, ibuprofen, glipizide, and amlodipine.
Blood pressure is 130/86 mm Hg and pulse is 72/min.  Cardiac examination reveals a grade 2/6 systolic ejection murmur at the base.  The lungs are clear and there is no jugular venous distension.  Tibial pulses are 1+ and the patient has trace pedal edema of the ankles bilaterally.
Serum creatinine is 2 mg/dL and urinalysis shows 2+ proteinuria.
In addition to using the smallest dose of a third-generation contrast agent and prehydrating with normal saline, which of the following is the most appropriate precaution for this patient's angiography?

Quizplus · Accepted Answer

This patient with chronic kidney disease is at risk for contrast-induced nephropathy (CIN) from her impending angiography. The etiology of CIN likely includes both direct cytotoxicity and renal vasoconstriction. Acute kidney injury (eg, elevated creatinine, electrolyte abnormalities) develops 24-48 hours after contrast administration, and patients often have a low fractional excretion of sodium (<1%), even in the absence of clinical volume depletion. Although the risk of CIN is negligible in patients with normal renal function, patients with chronic kidney disease (particularly those with diabetic nephropathy) are at increased risk. Additional risk factors include the use of large contrast volumes and older, first-generation contrast agents. Preventive measures include avoidance of nonsteroidal anti-inflammatory drugs (which can worsen vasoconstriction), periprocedural infusion of normal saline, and use of the smallest possible volume of contrast media. (Choices B, C, D, and E) Other suggested measures for preventing CIN include agents to force diuresis (eg, mannitol, furosemide), prevent renal vasoconstriction (eg, dopamine, fenoldopam), rapidly remove contrast material (eg, hemodialysis), or inhibit oxidative stress (eg, acetylcysteine). However, none has been shown to have a clear benefit. Educational objective: Patients with chronic kidney disease are at risk for contrast-induced nephropathy. Preventive measures include avoidance of nonsteroidal anti-inflammatory drugs, periprocedural infusion of normal saline, and use of the smallest possible volume of contrast media. __________ References: The prevention of contrast-induced nephropathy. (http://www.ncbi.nlm.nih.gov/pubmed/24994723)

A 67-Year-Old Woman Is Evaluated for Intermittent Claudication Prior to Angiography