X-ray examination of the GIT 5 Flashcards
What are the symptoms of vasovagal reactions caused by contrast media?
• Hypotension.
• Bradycardia.
• Dizziness.
• Pallor.
• Syncope (fainting).
Why is monitoring crucial after contrast media administration?
• Immediate detection of life-threatening reactions (e.g., severe hypotension, bronchospasm).
• Early intervention prevents progression to severe complications.
• Delayed reactions might still occur; patient education ensures timely medical attention.
What is the significance of osmolality in contrast media reactions?
• High Osmolality: Increases risk of chemotoxic effects, such as pain, renal impairment, and circulatory disturbances.
• Low Osmolality: Reduces the incidence of adverse reactions and is safer, especially in high-risk patients.
What are the potential renal effects of iodine-based contrast media, and how can they be mitigated?
• Effects: Contrast-induced nephropathy (CIN), characterized by an acute decrease in kidney function.
• Mitigation:
1. Ensure adequate hydration before and after the procedure.
2. Use the lowest effective contrast dose.
3. Avoid nephrotoxic drugs in conjunction with contrast administration.
How does methylprednisolone premedication work to prevent contrast reactions?
• It suppresses the immune response and reduces inflammation, minimizing the risk of anaphylactoid reactions.
• Typically administered orally in two doses: 6–12 hours and 2 hours before the procedure.
What factors should influence the choice of contrast media for a specific patient?
• Patient history of allergies or prior reactions to contrast.
• Pre-existing conditions (e.g., asthma, cardiac or renal issues).
• Requirement for high or low osmolality agents based on risk factors.
• Type of imaging modality and diagnostic goal.
How does anxiety influence contrast media reactions, and how can it be managed?
• Influence: Anxiety can exacerbate symptoms such as tachycardia, dizziness, and vasovagal reactions.
• Management:
1. Reassure and calm the patient.
2. Provide clear explanations about the procedure.
3. Use distraction techniques to reduce stress.
What role does hydration play in preventing chemotoxic reactions to contrast media?
• Promotes rapid renal clearance of contrast agents, reducing kidney damage.
• Prevents dehydration, which is a risk factor for nephropathy.
What are the key differences between ionic and non-ionic contrast agents in terms of patient safety?
• Ionic Agents: Higher osmolality, greater risk of adverse reactions, less expensive.
• Non-ionic Agents: Lower osmolality, reduced side effects, preferred for high-risk patients despite higher cost.
How should epinephrine be administered in the event of a severe reaction to contrast media?
• Intramuscular injection in the mid-outer thigh for rapid absorption.
• Dosage: Typically 0.3–0.5 mg for adults, repeated every 5–15 minutes as needed.
What diagnostic tests should be considered as alternatives to iodine-based contrast media?
• Ultrasound: Safe and effective for many conditions without contrast.
• MRI: Particularly useful for soft tissue imaging and can use gadolinium-based agents instead of iodine.
What signs indicate that a patient may be experiencing a chemotoxic reaction during imaging?
• Sensation of heat or burning at the injection site.
• Circulatory disturbances, such as light-headedness.
• Symptoms of renal impairment, like decreased urine output.
What medications are essential for managing contrast-induced bronchospasm?
• Primary Medication: Albuterol/salbutamol (inhaler or nebulizer).
• Adjuncts: Epinephrine for severe cases, corticosteroids to reduce inflammation.
How can radiographers prepare for potential emergencies involving contrast media?
- Conduct thorough pre-procedure assessments.
- Ensure emergency drugs (e.g., epinephrine, atropine) and equipment (e.g., oxygen supply, defibrillator) are available.
- Maintain up-to-date training in managing adverse reactions.
What are the possible cardiac effects of epinephrine used during severe reactions?
• Positive Effects: Increases heart rate and contractility to support blood circulation.
• Potential Risks: Can exacerbate hypertension or provoke arrhythmias, especially in cardiac patients.
Why should high-risk patients remain under observation for at least one hour post-contrast administration?
• Delayed or prolonged reactions may manifest beyond the standard 30-minute observation window.
• Close monitoring allows for immediate intervention if symptoms escalate.
What are the advantages of non-ionic, low-osmolality contrast agents in high-risk patients?
• Reduced risk of allergic-like reactions.
• Lower incidence of nephrotoxicity and chemotoxic side effects.
• Safer for patients with pre-existing conditions like asthma or renal disease.
