X-ray examination of GIT 3 Flashcards
What precautions should be taken to prevent or mitigate contrast media reactions in high-risk patients?
- Obtain a thorough medical and allergy history (e.g., asthma, allergies, cardiopulmonary issues).
- Use non-ionic, low-osmolality contrast agents.
- Premedicate with corticosteroids and antihistamines if the risk is significant.
- Ensure close monitoring and emergency equipment readiness during and after administration.
Why is it important to differentiate between mild and moderate reactions during a procedure?
• Mild Reactions: Require minimal intervention, mostly observation and reassurance.
• Moderate Reactions: Require active management to prevent escalation to severe or life-threatening conditions.
How do contrast-induced bronchospasm and laryngeal edema differ in severity and management?
• Bronchospasm: Presents as difficulty breathing; managed with bronchodilators.
• Laryngeal Edema: Can obstruct the airway, requiring immediate interventions like intubation or emergency tracheotomy.
What delayed adverse reactions to contrast media are considered most frequent, and how should they be addressed?
• Most Frequent Reactions: Skin rash (cutaneous xanthem), nausea, drowsiness, pruritus.
• Management: Inform patients to report symptoms to their physician if they persist or worsen.
How should tachycardia or bradycardia as a moderate reaction be managed during contrast administration?
• Tachycardia: Administer beta-blockers or calm the patient if anxiety-induced.
• Bradycardia: Use atropine to increase heart rate if symptomatic.
What are some strategies to minimize the risk of chemotoxicity in contrast media administration?
- Limit the dose and volume of the contrast media used.
- Use the lowest concentration sufficient for diagnostic purposes.
- Hydrate the patient before and after the procedure to promote renal clearance.
What are the potential consequences of not monitoring a patient closely after administering contrast media?
• Missed recognition of severe or moderate immediate reactions.
• Delayed intervention in progressing symptoms such as laryngeal edema or hypotension.
• Increased risk of adverse outcomes, including hospitalization or fatality.
What distinguishes dose-independent anaphylactoid reactions from true allergies?
• Anaphylactoid reactions mimic allergic responses but are not immune-mediated and occur without prior sensitization.
• True allergies involve an IgE-mediated immune response requiring prior exposure to the allergen.
Why is a small test dose of contrast media ineffective in preventing anaphylactoid reactions?
• Anaphylactoid reactions are not dose-dependent; even a small dose can trigger severe reactions.
• Testing does not reliably predict the occurrence or severity of future reactions.
What are the key differences between ionic and non-ionic iodine contrast media in terms of side effects?
• Ionic: Higher osmolality, dissociate into ions, higher likelihood of adverse reactions.
• Non-ionic: Lower osmolality, do not dissociate, safer with fewer side effects.
How does the osmolality of contrast media affect the risk of chemotoxicity?
• Higher osmolality increases the risk of local tissue damage and systemic effects, such as pain and nephrotoxicity.
• Low-osmolality agents are better tolerated, especially in patients with compromised kidney function.
Why are patients with cardiopulmonary conditions at higher risk for contrast-induced reactions?
• Pre-existing instability in cardiovascular or respiratory systems can exacerbate reactions like bronchospasm, hypotension, or arrhythmias.
What specific instructions should patients receive regarding delayed reactions?
• Monitor for symptoms such as skin rashes, headache, or nausea within 7 days post-procedure.
• Seek medical help if symptoms become severe or persistent.
How can radiology departments ensure preparedness for severe contrast reactions?
• Maintain emergency response protocols and staff training.
• Stock medications such as epinephrine, antihistamines, and bronchodilators.
• Ensure oxygen, defibrillators, and intubation kits are readily available.
What are the implications of profound hypotension as a severe reaction to contrast media?
• Symptoms: Extremely low blood pressure, shock, organ hypoperfusion.
• Intervention: Administer fluids, vasopressors, and monitor vitals closely to prevent irreversible damage.
