Intravascular Contrast Agents Flashcards
What should be the initial steps if a patient experiences ventricular fibrillation with contrast injection?
Stop the injection, disengage the catheter, and instruct the patient to cough if conscious.
These steps aim to clear contrast from the myocardium and address the arrhythmia immediately.
Which contrast agents are associated with more contrast-induced nephropathy?
High-osmolar agents (diatrizoate).
Low-osmolar or iso-osmolar agents are preferred due to lower nephrotoxicity.
What is one of the preferred contrast agents due to its nephrotoxic profile?
Nonionic iso-osmolar iodixanol.
It is less nephrotoxic than the ionic low-osmolar ioxaglate.
True or False: Patients with a prior hypersensitivity reaction to contrast should receive corticosteroids as a prep.
True.
The prep is recommended even though the risk of repeat reaction with low-osmolar contrast is lower.
What has been debunked regarding shellfish allergy and contrast allergy?
The theory that shellfish allergy confers a higher risk of contrast allergy.
The actual allergen in shellfish is tropomyosin, which is not present in contrast media.
How does LVEDP-guided hydration compare to standard hydration in preventing contrast-induced nephropathy?
CIN occurred less frequently (6.7% vs. 16.3%; relative risk 0.41; p = 0.005) in patients with LVEDP-guided hydration.
This finding is based on the POSEIDON randomized controlled trial.
What complication can occur from transcatheter aortic valve replacement (TAVR)?
Atheroembolism.
This can lead to a rapid rise in creatinine and renal failure.
What is the typical role of rapid delivery of contrast agents in imaging?
To ensure adequate visualization of the left ventricle and thoracic aorta.
Typical rates may be modified based on heart size or cardiac output.
What should be administered immediately in case of a severe anaphylactoid reaction to contrast?
IV epinephrine.
Corticosteroids and other medications may be given later.
What indicates severe laryngeal edema and impending airway collapse in a patient with hypersensitivity reaction?
Stridor and angioedema.
Delay in intubation could lead to complete airway collapse.
What is the risk of contrast-induced nephropathy (CIN) associated with pre-existing chronic renal insufficiency?
It is a significant risk factor.
Other factors include diabetes mellitus, advanced age, and hemodynamic instability.
What is a common misconception about metformin and contrast-related nephropathy?
Metformin does not increase the risk of contrast-related nephropathy.
However, its use is contraindicated in patients with impaired renal clearance.
What is the typical recovery timeline for renal function after contrast-induced nephropathy?
Typically recovers within 2 weeks.
In contrast, acute kidney injury from atheroembolic disease may last 3 to 8 weeks.
What is the fractional excretion of sodium’s reliability in distinguishing CIN from prerenal azotemia?
It is not a reliable way to distinguish between them.
In CIN, creatinine typically peaks at 48 to 72 hours.
What is a proposed mechanism of contrast-induced nephropathy?
Renal hypoperfusion due to renal vasoconstriction and hyperviscosity.
Direct renal toxicity is also a mechanism.
