ARRT Contrast Media and Pharmacology 1 — Questions and Answers
Question 1: Which type of iodinated contrast media is considered safest for patients with a history of allergic reactions?
- Ionic high-osmolar
- Nonionic low-osmolar (Correct answer)
- Ionic low-osmolar
- Nonionic high-osmolar
Correct answer: Nonionic low-osmolar
Nonionic low-osmolar contrast media have significantly fewer adverse reactions and are the preferred choice for high-risk patients.
Question 2: What is the most common mild adverse reaction to iodinated contrast media?
- Bronchospasm
- Nausea and vomiting (Correct answer)
- Hypotension
- Urticaria
Correct answer: Nausea and vomiting
Nausea and vomiting are the most frequently reported mild reactions following intravenous iodinated contrast administration.
Question 3: Before administering iodinated contrast media, which lab value is most critical to assess renal function?
- BUN
- Serum creatinine / eGFR (Correct answer)
- ALT
- Hemoglobin
Correct answer: Serum creatinine / eGFR
Serum creatinine and eGFR are used to evaluate kidney function and assess the risk of contrast-induced nephropathy.
Question 4: Which medication is commonly used as premedication to reduce the risk of a repeat contrast reaction?
- Metformin
- Prednisone (corticosteroid) (Correct answer)
- Warfarin
- Insulin
Correct answer: Prednisone (corticosteroid)
Oral corticosteroids such as prednisone are given prior to contrast injection in patients with a history of prior reactions to reduce reaction severity.
Question 5: What is the primary treatment for anaphylactic shock caused by contrast media?
- Diphenhydramine IV
- Epinephrine IM (Correct answer)
- Normal saline bolus only
- Atropine IV
Correct answer: Epinephrine IM
Epinephrine administered intramuscularly is the first-line emergency treatment for anaphylaxis regardless of cause.
Question 6: Why should metformin be held after contrast media administration in patients with diabetes?
- Contrast increases blood glucose levels
- Risk of lactic acidosis if renal function is impaired (Correct answer)
- Metformin reduces contrast effectiveness
- Contrast causes hypoglycemia
Correct answer: Risk of lactic acidosis if renal function is impaired
If contrast media causes renal impairment, metformin can accumulate and lead to life-threatening lactic acidosis.
ARRT Contrast Media and Pharmacology 1
Which type of iodinated contrast media is considered safest for patients with a history of allergic reactions?