Contrast Administration

What is water-soluble iodine chemically attached with to counteract it’s toxicity to the human body?

Benzene Ring

What is a benzene ring

An organic compound that is not so easily rejected by the body

What is the only kind of contrast agent that is safe for IV injection?

Water-soluble iodine

Ionic vs. non-ionic iodine

Ionic

→molecule breaks apart into multiple charged particles called ions

Nonionic

→molecule stays in one piece & there are NO charged particles

Why is ionic water-soluble iodine not desirable?

When placed in a solution, it breaks apart into charged particles. This causes higher toxicity and osmolarity, and is more damaging to the body.

Term for the concentration of particles in a fluid

Osmolarity

Benefits of non-ionic water-soluble iodine

When placed in a solution, molecule does not break apart and there are no charged particles, which means low toxicity and osmolarity.

Before a patient receives IV contrast, what prep should be done for the patient?

Increase fluids before and after so kidneys filter out the contrast easier

but keep NPO about an hour prior to exam

What must be checked before giving a patient IV contrast?

Kidney function (BUN, creatinine, and GFR values)

What can a patient be pre-medicated with if they have a known iodine allergy?

1. Corticosteroids (prednisone), given twice = 12 hours + 1 hour before the scan

2. Anti-histamines (benadryl), given 1 hour before the scan

Leakage of contrast outside the vessel, causing swelling/burning/tightness

Extravasation

What three things should be done for extravasation?

1. Informing the provider

2. Elevating extremity

3. Using hot / cold compress

What are the symptoms for a mild reaction to IV contrast?

1. Hives

2. Pruritus (itching)

3. Rhinorrhea (runny nose)

4. Coughing

What should be done for a mild reaction to IV contrast?

1. Monitor for 30 minutes

2. Check vital signs

3. Possible antihistamine

What are the symptoms for a moderate allergic reaction to IV contrast?

1. Diffuse hives

2. Vomiting

3. Laryngeal Edema

4. Tachycardia

What should be done for moderate allergic reaction to IV contrast?

1. Monitor patient

2. Check vital signs

3. Get IV access

4. Likely antihistamine

What are the symptoms for a severe allergic reaction to IV contrast?

1. AMS

2. Pulmonary edema

3. Laryngeal edema

4. Tachycardia

What should be done for a severe allergic reaction to IV contrast?

1. Call a code

2. Administer epinephrine

Term for a decrease in renal function following IV contrast administration

Nephrotoxicity

What is the atomic number for barium?

56

Barium sulfate is used almost exclusively for evaluation of what part of the body?

The GI tract

When barium is ingested in the GI tract, this is known as what type of administration?

Enteral (can be oral or rectal)

Administration of contrast/medications outside the GI tract is known as what kind of administration?

Parenteral

What is the biggest contraindication for barium?

A perforated bowel

Why are allergies to barium rare?

Because it’s not actually absorbed

What are some common side effects of barium?

Diarrhea, nausea, vomiting, constipation (mostly due to dehydration)