Question

Provide complete answers to the following items

• Identification (signs and symptoms) and treatment of adverse reactions to contrast media in CT.
• List common drugs used by medical Dr.s and registered nurses to treat patient hypersensitivities to iodinated contrast media.
• How soon after injection of iodinated contrast could a patient begin having some sort of reaction?

Answer 1

Contrast media is used in CT scan inorder to ease the visualization of internal parts. But sometimes the use of contrast media may cause adverse reactions on few patients. These symptoms can be categorized into mild, moderate and severe. And delayed reactions also there.

Signs and symptoms of use of contrast media are

1. Mild :-
   • Nausea, vomiting, headache, mild urticaria, priorities, flushing etc
   • Treatment: supportive measures
2. Moderate:-
   • Breathing difficulty, bronchospasm, vasovagal attacks, severe vomiting, facial edema etc
   • Treatment includes: prompt medical attention is needed.
   • oxygentherapy ( by mask)
   • Beta-2- agonists ( terbutaline, Albuterol) and epinephrine intramuscularly
   • Metered dose inhaler
   • Antihistamines in case of urticaria
3. Severe
   • Severe reactions may sometimes life threatening too
   • Symptoms like Convulsions, respiratory or cardiac arrest, pulmonary edema, hypovolemic shock etc
   • Treatment: supine position
   • Epinephrine intramuscularly
   • Corticosteroids
   • Albuterol and epinephrine nebulizations if needed
4. Delayed reactions
   • May occur between one hour or one week.
   • Maculopapular rash, angioedema, erythema, urticaria
   • Mostly not reported.

Drugs used to treat adverse reactions caused by iodinated contrast media includes:-

• Elevated position during hypotension
• Diphenhydramine IV
• Inhaled beta 2 agonist
• Hydrocortisone IV
• H2 blocker IV

The reaction time to contrast varies in patient to patient.it may ranges immediately after dye injection to one week. Delayed reactions are very rare.