Review Question - QID 104614

This patient is most likely presenting with contrast-induced nephropathy, of which the risk can be reduced in patients who are well-hydrated prior to procedure.

Acute kidney injury (AKI) classically presents with anorexia, fatigue, mental status changes, nausea and vomiting, pruritus, or shortness of breath. Physical exam may reveal asterixis and myoclonus, pericardial or pleural rub, arrhythmias, oliguria, peripheral edema or pulmonary rales. In the evaluation of patients with AKI, pass a urinary catheter to rule out obstruction (post-renal causes), as well as use renal ultrasound to rule-out upstream obstruction (stone).

Maddox discusses adverse reactions to contrast agents, which may range from benign symptoms such as itching to a life-threatening emergency. Renal toxicity (as in this case) is a well known complication of IV contrast. It is essential to use the least amount of contrast material possible especially in cases of renal insufficiency.

Au et al. discuss the prevention of contrast-induced nephropathy (CIN), which unfortunately has a paucity of solid clinical evidence. Currently, the best data supports preprocedural hydration with isotonic solution as the standard of care. They note that the best prevention is judicious use of contrast-based imaging studies.

Illustration A demonstrates a pathway for determining which patients are at risk for contrast-induced nephropathy.

Incorrect Answers:
Answer 2: Some studies propose the use of NAC in the prevention of CIN; however, more evidence supports efficacy with hydration preprocedurally, though the risks of NAC are minimal.
Answers 3-5: These actions would not be warranted in the prevention of CIN.