This page only applies to contrast agents usually used for CT scans. MRIs with contrast use gadolinium, which can cause nephrogenic systemic fibrosis in patients with renal dysfunction.

Background

Often defined as creatinine rise of more than 0.5mg/dL or ≥25% above baseline [1]

Vasoconstriction leading to ischemia in the deeper portion of the outer medulla

Toxic to kidney tubular cells, inducing vacuolization, change in mitochondrial function, and apoptosis

Less likely to occur with low and iso-osmolar contrast agents

Healthy Patients

CIN not likely to occur in patients with a Cr<1.5 or a GFR >60ml/min[2][3]

Impaired Renal Function

Administration should follow your local hospital protocols

Less likely to occur in iso-osmolar contrast agents (iodixanol/Visipaque) and contrary to traditional teaching, maybe not even an occurrence in patients with creatinine greater than 2.0mg/dL. [4]

Risk Factors

Renal disease

Recent contrast study within 72 hrs

Hypotension

Dehydration

DM

Multiple myeloma

Age > 70

Hypertension

Hyperuricemia

Diuretics

Clinical Features

Decreased urine output

0.5mg/dl absolute or >25% relative increase in serum creatinine 48-72hrs after contrast exposure

Differential Diagnosis

Poor renal perfusion

Nephrotoxic medications

Contrast induced complications

Evaluation

Same as for AKI

Management

Hallmark of management is prevention in at-risk patients.

Hydration

Isotonic hydration with normal saline 1-1.5L (15ml/kg) prior to the contrast load in patients with impaired renal function may lessen the chances of developing CIN [5] [6] [7]

If suspect the development or confirm the diagnosis continue adequate hydration to maintain urine output of 0.7cc-1cc/kg

Early research suggests a potential benefit for forced furosemide diuresis (300ml/h) while continuing intravenous hydration fluids (0.5mg/kg) but should be performed in consult with radiologist and nephrologist[8]

Is not useful for preventing CIN[9][7]

Other Measures

Low osmolar contrast agents

Bicarbonate infusion

Hypertonic saline

See Also

References