2. • Types of adverse reaction
• Idiosyncratic reactions (even tiny amounts of
contrast media may cause it)
• Chemotoxic reactions (the more contrast, the
higher the likelihood)
• Combination of both
3. Idiosyncratic Reactions
• Unpredictable
• Not dose-dependent
• Release of histamine and other active
biological mediators such as serotonin,
prostaglandins, bradykinin, leukotrienes,
adenosine and endothelin
• Cannot be reliably predicted and are not
preventable.
4. • Not dose-dependent and death has been
known to occur following a 1-mL IV test dose,
or after the full dose of contrast medium has
been given after a negative test dose.
5. Chemotoxic Reactions
• Determined by dose
• Molecular toxicity of each agent
• Physiological characteristics of the contrast
agents
• High osmolality (osmotoxicity) causes shift of
fluids from the intracellular to the
extracellular space, leading to cell
dehydration.
6. Vasomotor Reactions
• Severe hypotension,
• Tachycardia or bradycardia
• Anxiety, sweating
• Depression of myocardial contraction
8. Risk Factors for Acute Reactions
• Patient-related
– Patient with a history of Previous moderate or
severe acute reaction to an iodine-based contrast
agent
– Asthma
– Allergy requiring medical treatment
– Contrast medium-related - High osmolality ionic
contrast media
9. Reduce the Risk of an Acute Reaction
• For all patients
– Use a non-ionic contrast medium
– Keep the patient in the Radiology Department for
30 min after contrast medium injection
– Have the drugs and equipment for resuscitation
readily available
10. • For patients at increased risk of reaction
• Consider an alternative test not requiring an iodine-
based contrast agent
• Use a different iodine-based agent for previous reactors
to contrast medium
• Consider the use of premedication. Suitable
premedication regime is prednisolone 30 mg (or
methylprednisolone 32 mg) orally given 12 and 2 hours
before contrast medium
11. Acute Renal Adverse Reactions
(Contrast-Induced Nephropathy)
• In patients with reduced renal function, iodine
based contrast media may cause further
reduction in renal function.
• Mostly a transient one
• All iodine based contrast agents will cause
(ionic>>non ionic)
12. Risk Factors for Contrast Medium-
Induced Nephropathy
• Patient-related
– eGFR < 60 mL/min/1.73 m2 before intra-arterial administration
– eGFR < 45 mL/min/1.73 m2 before intravenous administration
In particular in combination with
– Diabetic nephropathy
– Dehydration
– Congestive heart failure (NYHA grade 3–4) and low LVEF
– Recent myocardial infarction (24h)
– Intra-aortic balloon pump
– Peri-procedural hypotension
– Low haematocrit level
– Age over 70
– Concurrent administration of nephrotoxic drugs
– Known or suspected acute renal failure
13. • Procedure-related
– Intra-arterial administration of contrast medium
High-osmolality agents
– Large doses of contrast medium
– Multiple contrast medium administrations within
a few days
14. Elective Examination
• Identify patients who require measurement of renal
function
– Patients with known eGFR < 60 mL/min/1.73 m2
– Patients who will receive intra-arterial contrast medium
– Age over 70
• Patients with a history of
– Renal disease
– Renal surgery
– Proteinuria
– Diabetes mellitus
– Hypertension
– Gout
– Recent nephrotoxic drugs
15. For at risk patients
• Consider an alternative imaging method not
using iodine-based contrast media.
• Discuss the need to stop nephrotoxic drugs
with the referring physician
• Start volume expansion
– A suitable protocol is intravenous normal saline,
1.0–1.5 mL/kg/h, for at least 6 h before and after
contrast medium
16. Time of Examination
• Use low or iso-osmolar contrast media
• Use the lowest dose of contrast medium which
yield a diagnostic result
After the Examination
• Continue volume expansion
• Determine eGFR 48–72 h after contrast
medium
17. Late Adverse Reactions
• Maculopapular rashes
• erythema
• swelling
• Pruritus
• Self limiting
• Risk factors for skin reactions
– Previous late contrast medium reaction
– Use of non-ionic dimer
18. Very Late Adverse Reactions
• Thyrotoxicosis
– Patients with untreated Graves’ disease
– Patients with multinodular goitre and thyroid
autonomy
Iodinated contrast media should not be given to
patients with manifest hyperthyroidism
