Repeated Medical PG Question- 50

Which among the following is not a risk factor for contrast-induced nephropathy?

A. Diabetic nephropathy

B. High osmolar agent

C. Obesity

D. Dehydration

Answer is C. High osmolar agent

Side effects of iodinated contrast material are:

▪️Idiosyncratic – Anaphylactoid reaction. They are complement-mediated reactions and not IgE. The patient develops bronchospasm and hypotension.

Dose-dependent side effect – Contrast-induced nephropathy and seen especially with high osmolar agents.

Contrast-induced nephropathy:

▪️The patient has non-oliguric transient nephropathy and occurs due to tubular damage. It is defined as the impairment of renal function and is measured as either a 25% increase in serum creatinine from baseline or 0.5 mg/dl increase in absolute value, within 48-72hrs of intravenous contrast administration.

Risk Factors for Contrast Medium-Induced Nephropathy:

1. Patient-related:

▪️eGFR < 60 mL/min/1.73 m2 before intra-arterial administration

▪️eGFR < 45 mL/min/1.73 m2 before intravenous administration

2. In particular in combination with:

Diabetic nephropathy

▪️Dehydration

▪️Congestive heart failure (NYHA grade 3–4) and low LVEF

▪️Recent myocardial infarction (

Intra-aortic balloon pump)

▪️Peri-procedural hypotension

▪️Low hematocrit level

▪️Age over 70

▪️Concurrent administration of nephrotoxic drugs

▪️Known or suspected acute renal failure

3. Procedure-related:

▪️Intra-arterial administration of contrast medium

▪️High-osmolality agents

▪️Large doses of contrast medium

▪️Multiple contrast medium administrations within a few days

▪️If the patient is on Metformin and is having de-arranged RFT, then before giving contrast agent metformin should be stopped since it can precipitate lactic acidosis