X-ray examinations of Gastrointestinal Tract Part 2 Flashcards
What are the two primary ways to categorize contrast media side effects or reactions?
- By severity: mild, moderate, severe, and delayed reactions.
- By type of adverse reaction: anaphylactoid reactions (dose-independent) and chemotoxicity (dose-dependent).
What defines severe contrast media reactions?
Life-threatening reactions requiring immediate medical intervention, characterized by severe symptoms that can rapidly escalate without prompt treatment.
What are the key characteristics of severe contrast media reactions?
Severe or progressive laryngeal edema, clinically manifest arrhythmias, profound hypotension, convulsions, unresponsiveness, or cardiopulmonary arrest.
What characterizes mild contrast media reactions, and how are they treated?
Characteristics: Self-limiting symptoms, no risk of further progression.
Examples: Nausea, vomiting, altered taste, rash, itching, pallor, dizziness, chills, warmth, nasal stuffiness.
Treatment: Observation and reassurance.
What defines moderate contrast reactions, and what are some examples?
Definition: Reactions requiring treatment but not immediately life-threatening.
Examples: Tachycardia/bradycardia, hypertension, bronchospasm, hypotension, laryngeal edema. Management: Prompt treatment with close observation.
What are delayed contrast reactions, and when do they typically occur?
Timing: Occur 3 hours to 7 days after administration. Symptoms: Cutaneous rash, pruritis, nausea, drowsiness, and headache. Management: Inform the patient about the possibility of delayed reactions, even though they are usually mild.
Differentiate between anaphylactoid and chemotoxic contrast reactions.
Anaphylactoid: Acute, dose-independent reactions occurring unpredictably in any patient. Chemotoxicity: Local or systemic effects that are dose-dependent, linked to concentration and volume of contrast media.
What are the key points regarding anaphylactoid reactions to contrast media?
Can occur even the first time contrast is administered. Severity is not dose-related, making small test doses ineffective. Past reaction does not guarantee recurrence but increases the risk.
What risk factors make a patient more susceptible to anaphylactoid reactions?
Allergic asthma, drug and food allergies, cardiopulmonary conditions.
How do delayed contrast reactions present, and why are they often missed?
Presentation: Mild symptoms like rash, nausea, and headache. Reason missed: Patients are usually discharged within 30 minutes of administration, so delayed reactions occur outside the observation period.
What is the role of radiologists and radiographers in managing contrast media reactions?
Ensure emergency drugs and equipment are readily available. Closely monitor patients immediately after administration. Educate patients on the possibility of delayed reactions.
Why are chemotoxic contrast reactions considered dose-dependent?
They occur due to the concentration, volume, or infusion rate of the contrast media, influencing their local or systemic toxic effects.
Why are anaphylactoid reactions unrelated to the osmolality of the contrast media?
They are independent of the physicochemical properties of the contrast media and occur unpredictably, even with isotonic solutions.
How should mild contrast reactions like nausea or itching be managed during a procedure?
Observe the patient for further symptoms. Reassure them as most mild reactions resolve spontaneously.
What immediate actions are necessary for severe contrast reactions like cardiopulmonary arrest?
Initiate advanced life support protocols. Administer emergency drugs. Ensure rapid transfer to a hospital for intensive care.
How should healthcare providers prepare for delayed contrast reactions?
Inform patients of the possibility and symptoms of delayed reactions. Provide instructions on when and how to seek medical help if symptoms develop.
