Chapter_023 contrast media combo DD (1)

To minimize adverse reactions:
- Obtain informed consent.
- Gather an accurate and thorough medical history, with a focus on allergies.
- Check blood urea nitrogen (BUN) and creatinine levels.
- Verify medications, especially those used to treat type II diabetes.

Key History Questions:
- History of kidney disease or failure ? Check inpatient chart for BUN and creatinine levels.
- History of diabetes? Check for metformin medication.
- History of heart disease or hypertension? Check current blood pressure.
- Any iodine contrast studies within the last 48 hours? Document when, which agent, concentration, and dose.
- Any allergies or previous allergic reactions to contrast medium? Note specific agents and reactions.
- Current medications, particularly beta-blockers and antihypertensives.

Reactions can range from mild to severe with no predictors.
Begin with a small amount of injection and monitor for signs/symptoms.
Patients at risk for reactions may be premedicated with antihistamines and/or corticosteroids.

Symptoms:
- Erythema- redness of the skin that may occur in localized areas or spread across larger regions.
- Urticaria- hives or welts on the skin that can vary in size and may be itchy.
- Bronchospasm- a sudden constriction of the muscles in the walls of the bronchioles, leading to difficulty in breathing and wheezing.
Treatment:
- Administer antihistamine (oral, IV, or IM).
- Use bronchodilators for bronchospasm.

Symptoms:
- Warmth, tingling, itching, dysphagia, laryngeal, and bronchial edema.
Treatment:
- Maintain airway, call code, administer epinephrine IV, and other needed drugs.

Uses: Visualizes anatomy not seen normally, utilizing photoelectric effect & high-atomic number elements.
Requires administration into the patient, attention to indications & contraindications, and careful monitoring of reactions.

Negative Contrast Agents:
- Low-atomic number elements, appear radiolucent on images (e.g., air).
Positive Contrast Agents:
- Higher atomic number elements, appear radiopaque on images (e.g., barium and iodides).

Ability to mix with body fluids.
Viscosity, ionic strength, persistence, iodine content, osmolality, and potential for toxicity.

Types:
- Ionic: Contains iodine with higher osmolality, greater chance of reactions, disrupts homeostasis.
- Nonionic: Lower osmolality, less chance of reaction, high cost, low toxicity.

Administered intravenously or intra-arterially.
Iodine concentration is crucial for x-ray attenuation.
Osmolality is related to the degree of adverse reactions; ionic contrast media is HOCM, while nonionic is LOCM.

Increased particles due to ionic HOCM injections can result in water from tissues moving into the vascular system via osmosis, potentially causing hypervolemia and adverse effects.
Understanding the differences in interaction between ionic (dissociates in blood) and non-ionic (remains whole) contrast agents is vital for patient care.

Toxicity is determined by:
- Chemical configuration, iodine concentration, osmolality, and rate of injection.
Non-ionic contrast media is generally less toxic due to lower osmolality and iodine concentration.

Administer contrast agents under qualified supervision, with thorough patient assessments.
Monitor patient comfort, recognize reactions, ensure patient care, and communication throughout the process.

Time-sensitive; contamination is a major concern, leading to image artifacts and unnecessary exposure.
Importance of biodistribution and recognition of contamination types (internal and external).

A thorough patient history and renal function evaluation are critical before administering contrast materials.
Specifically, metformin (Glucophage) use should be paused 48 hours around iodine contrast.

Contrast agents are essential in medical imaging; classified as positive or negative with reliance on the photoelectric effect.
Non-ionic, low-osmolality contrast media mitigate patient reactions, but vigilance remains essential in monitoring and management of reactions.