A 68-year-old man comes to the emergency department due to a cough. Chest x-ray shows no infiltrates but reveals a right upper lobe lung lesion incidentally. A chest CT scan with intravenous contrast reveals a 1x2 cm nodule in the right upper lobe. The patient is admitted to the hospital and is found to have worsening acute renal failure. Medical history is significant for hypertension, hyperlipidemia, diabetes, chronic kidney disease, and coronary artery disease. Pre-admission medications include aspirin, hydrochlorothiazide, clopidogrel, metoprolol, atorvastatin, metformin, and lisinopril, all of which he has taken for several years. He has no known drug allergies. The patient is a former smoker and does not use alcohol or illicit drugs. Blood pressure is 140/90 mm Hg and has remained in the 140s/90s throughout the hospitalization. Physical examination is unremarkable. Laboratory results are as follows: Over the course of the next week, the patient's renal function returns to normal. Which of the following would have been most helpful in preventing his acute kidney injury?

Question

A 68-year-old man comes to the emergency department due to a cough.  Chest x-ray shows no infiltrates but reveals a right upper lobe lung lesion incidentally.  A chest CT scan with intravenous contrast reveals a 1x2 cm nodule in the right upper lobe.  The patient is admitted to the hospital and is found to have worsening acute renal failure.  Medical history is significant for hypertension, hyperlipidemia, diabetes, chronic kidney disease, and coronary artery disease.  Pre-admission medications include aspirin, hydrochlorothiazide, clopidogrel, metoprolol, atorvastatin, metformin, and lisinopril, all of which he has taken for several years.  He has no known drug allergies.  The patient is a former smoker and does not use alcohol or illicit drugs.  Blood pressure is 140/90 mm Hg and has remained in the 140s/90s throughout the hospitalization.  Physical examination is unremarkable.  Laboratory results are as follows:  Over the course of the next week, the patient's renal function returns to normal.  Which of the following would have been most helpful in preventing his acute kidney injury?

Quizplus · Accepted Answer

Explanation: 11ec25c8_d4d7_9e0e_bc81_2d54b04fcc4c_MD0003_00 This patient has acute kidney injury following administration of a radiologic contrast agent, consistent with contrast-induced nephropathy (CIN). Patients with CIN typically have an acute rise in creatinine within 24-48 hours of contrast administration followed by a gradual return to baseline. The etiology of CIN remains unclear but is likely multifactorial, and includes: Direct cytotoxicity causing acute tubular necrosis with muddy brown casts noted on urinalysis Renal vasoconstriction causing pre-renal injury (fractional excretion of sodium <1%), even in the absence of clinical volume depletion Contrast administration has negligible risk in patients with normal renal function, but those with underlying chronic kidney disease (particularly diabetic nephropathy), such as this patient, are at increased risk. Preventive measures include avoidance of nonsteroidal anti-inflammatory drugs (NSAIDs), which can worsen vasoconstriction, periprocedural administration of intravenous normal saline, and using the smallest possible volume of contrast media. Previously, acetylcysteine and sodium bicarbonate were recommended; however, recent trials indicate that these have no clear benefit in the prevention of CIN. (Choice A) High-flow oxygen has no role in preventing CIN, and inappropriate administration of supplemental oxygen can lead to oxygen toxicity. (Choice B) Diuretics can reduce the volume overload sometimes associated with renal failure but do not prevent CIN. (Choice C) Systemic glucocorticoids (eg, prednisone) are used to prevent hypersensitivity reactions (eg, flushing, urticaria, bronchospasm) in patients with known allergy to contrast media. However, glucocorticoids do not prevent CIN and can cause fluid retention and elevated blood pressure in patients with renal insufficiency. (Choice E) Clopidogrel, a P2Y₁₂ inhibitor, is commonly used with aspirin to prevent re-thrombosis following coronary artery stenting or acute coronary syndrome. Although NSAIDs should be held prior to contrast administration, antiplatelet therapy with low-dose aspirin and/or clopidogrel may be continued. ₁₂ Educational objective: Contrast-induced nephropathy is characterized by an acute rise in creatinine after radiologic contrast administration followed by a gradual return to baseline. Patients with chronic kidney disease are at increased risk. Preventive measures include avoidance of nonsteroidal anti-inflammatory drugs, periprocedural saline hydration, and using the smallest possible volume of contrast media.

A 68-Year-Old Man Comes to the Emergency Department Due to a Cough