CIR Contrast Media Administration & Adverse Reaction Management 1 — Questions and Answers
Question 1: Which type of contrast media is preferred for cardiac catheterization due to its lower risk of adverse hemodynamic effects?
- High-osmolar ionic contrast media
- Low-osmolar non-ionic contrast media (Correct answer)
- High-osmolar non-ionic contrast media
- Iso-osmolar ionic contrast media
Correct answer: Low-osmolar non-ionic contrast media
Low-osmolar non-ionic contrast media is preferred because it produces fewer hemodynamic disturbances and cardiac side effects compared to high-osmolar ionic agents.
Question 2: Which iodinated contrast agent is classified as iso-osmolar, with osmolality approximating that of blood?
- Iohexol (Omnipaque)
- Iopamidol (Isovue)
- Iodixanol (Visipaque) (Correct answer)
- Ioversol (Optiray)
Correct answer: Iodixanol (Visipaque)
Iodixanol (Visipaque) is the primary iso-osmolar contrast agent (~290 mOsm/kg), matching blood osmolality and reducing osmotic stress on vessels and kidneys.
Question 3: What iodine concentration range is typically used in contrast agents for coronary angiography?
- 100–150 mg I/mL
- 200–240 mg I/mL
- 300–370 mg I/mL (Correct answer)
- 400–450 mg I/mL
Correct answer: 300–370 mg I/mL
Coronary angiography requires contrast media with iodine concentrations of 300–370 mg I/mL to achieve adequate vessel opacification at the flow rates used.
Question 4: What is the primary mechanism by which contrast media causes contrast-induced nephropathy (CIN)?
- Allergic inflammation of the glomeruli
- Direct tubular toxicity combined with renal medullary vasoconstriction (Correct answer)
- Contrast precipitation blocking renal tubules
- Immune complex deposition in Bowman's capsule
Correct answer: Direct tubular toxicity combined with renal medullary vasoconstriction
CIN results from direct cytotoxic effects on renal tubular epithelial cells combined with vasoconstriction of the renal medullary vessels, causing ischemia.
Question 5: Which pre-procedure intervention has the MOST consistent evidence for reducing contrast-induced nephropathy risk?
- N-acetylcysteine administration
- Sodium bicarbonate infusion
- Intravenous normal saline hydration (Correct answer)
- Prophylactic furosemide diuresis
Correct answer: Intravenous normal saline hydration
IV hydration with isotonic normal saline before and after contrast administration is the most consistently evidence-supported strategy for preventing CIN by maintaining renal perfusion.
Question 6: What is the most common hemodynamic side effect observed with intracoronary contrast injection?
- Anaphylaxis
- Acute contrast-induced nephropathy
- Transient bradycardia and hypotension (Correct answer)
- Ventricular fibrillation
Correct answer: Transient bradycardia and hypotension
Transient bradycardia and hypotension are the most common side effects of intracoronary contrast injection due to the direct depressant effects of contrast on myocardial conduction and contractility.
Question 7: Which property of contrast media MOST directly contributes to prolonged QT interval on ECG during coronary injections?
- High iodine concentration
- High viscosity
- High osmolality and ionicity (Correct answer)
- Elevated pH of the solution
Correct answer: High osmolality and ionicity
High osmolality and ionicity of contrast media are associated with greater QT prolongation due to their effects on myocardial electrolyte balance and membrane potential.
CIR Contrast Media Administration & Adverse Reaction Management 1
Which type of contrast media is preferred for cardiac catheterization due to its lower risk of adverse hemodynamic effects?