A. General adverse reactions
A.1.1. Acute Adverse Reactions to Iodine-based Contrast Media
A.1.2. Acute Adverse Reactions to Gadolinium-based Contrast Media (non-organ specific)
A.1.3. Management of Acute Adverse Reactions
A.1.4. Recording Acute Adverse Reactions
A.1.5. Review of Treatment Protocols
A.3. Very Late Adverse Reactions
A.3.2. Nephrogenic Systemic Fibrosis
A. GENERAL ADVERSE REACTIONS
A.1. Acute Adverse Reactions
Definition: An adverse reaction which occurs within 1 hour of contrast medium injection.
The same acute adverse reactions are seen after iodine- and gadolinium-based contrast agents and after ultrasound contrast agents. The incidence is highest after iodine-based contrast agents and lowest after ultrasound agents.
Classification
Acute reactions are either allergy-like, hypersensitivity reactions or chemotoxic responses. Allergy-like reactions may or may not be true IgE-mediated allergy.
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Allergy-like/ Hypersensitivity |
Chemotoxic |
Mild |
Mild urticaria Mild itching Erythema |
Nausea/mild vomiting Warmth/chills Anxiety Vasovagal reaction which resolves spontaneously |
Moderate |
Marked urticaria Mild bronchospasm Facial/laryngeal edema Vomiting |
Severe vomiting Vasovagal attack |
Severe |
Hypotensive shock Respiratory arrest Cardiac arrest |
Arrythmia Convulsion |
Note:
- Not all symptoms experienced by patients in the hour after contrast medium injection are adverse reactions to the contrast agent.
- Patient anxiety may cause symptoms after contrast medium administration (Lalli effect).
- When a new contrast medium is first introduced, adverse effects tend to be over-reported (Weber effect).
A.1.1. Acute Adverse Reactions to Iodine-based Contrast Media
Risk factors for acute reactions |
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Patient-related |
Patients with a history of
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Contrast medium-related |
Note:
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To reduce the risk of an acute reaction |
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For all patients |
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For patients at increased risk of reaction (see risk factors above) |
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Be prepared for an acute reaction in all patients |
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Warming iodine-based contrast medium before administration |
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Extravascular administration of iodine-based contrast medium |
When absorption or leakage into the circulation is possible, take the same precautions as for intravascular administration. |
A.1.2. Acute Adverse Reactions to Gadolinium-based Contrast Media (non-organ specific)
Note:
The risk of an acute reaction to a gadolinium-based contrast agent is lower than the risk with an iodine-based contrast agent, but severe reactions to gadolinium-based contrast media may occur.
Risk factors for acute reactions |
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Patient-related |
Patients with a history of
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Contrast medium-related |
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To reduce the risk of an acute reaction |
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For patients at increased risk of reaction (see risk factors above) |
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Be prepared for an acute reaction in all patients |
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A.1.3. Management of Acute Adverse Reactions
The management is the same for acute adverse reactions after iodine- and gadolinium-based and ultrasound contrast agents.
First-line emergency drugs and equipment which should be in the examination room
- Oxygen
- Adrenaline 1:1,000
- Antihistamine H1 – suitable for injection
- Atropine
- ß2-agonist metered dose inhaler
- I.V. Fluids – normal saline or Ringer’s solution
- Anti-convulsive drugs (diazepam)
- Sphygmomanometer
- One-way mouth “breather” apparatus
Simple guidelines for first-line treatment of acute reactions to all contrast media
When an acute reaction occurs, check for the following:
- Skin erythema, urticaria
- Nausea, vomiting
- Decreased blood pressure, abnormal heart rate
- Dyspnea, bronchospasm
Nausea/Vomiting
Transient: Supportive treatment.
Severe, protracted: Appropriate antiemetic drugs should be considered.
Note: Severe vomiting may occur during anaphylaxis.
Urticaria
Scattered, transient: Supportive treatment including observation.
Scattered, protracted: Appropriate H1-antihistamine intramuscularly or intravenously should be considered. Drowsiness and/or hypotension may occur.
Generalized: Appropriate H1-antihistamine intramuscularly or intravenously should be given. Drowsiness and/or hypotension may occur. Consider adrenaline 1:1,000, 0.1-0.3 ml (0.1-0.3 mg) intramuscularly in adults, 50% of adult dose to pediatric patients between 6 and 12 years old and 25% of adult dose to pediatric patients below 6 years old. Repeat as needed.
Note: Urticaria may precede anaphylaxis, so the patient should be observed carefully.
Bronchospasm
1. Oxygen by mask (6-10 l/min).
2. ß-2-agonist metered dose inhaler (2-3 deep inhalations).
3. Adrenaline.
3.a. Normal blood pressure
Intramuscular: 1:1,000, 0.1-0.3 ml (0.1-0.3 mg) [use smaller dose in a patient with coronary artery disease or elderly patient]. In pediatric patients: 50% of adult dose to pediatric patients between 6 and 12 years old and 25% of adult dose to pediatric patients below 6 years old. Repeat as needed.
3.b Decreased blood pressure
Intramuscular: 1:1,000, 0.5 ml (0.5 mg), In pediatric patients:
6-12 years: 0.3 ml (0.3 mg) intramuscularly.
< 6 years: 0.15 ml (0.15 mg) intramuscularly.
Laryngeal edema
1. | Oxygen by mask (6-10 l/min). |
2. |
Intramuscular adrenaline (1:1,000), 0.5 ml (0.5 mg) for adults, repeat as needed. In pediatric patients:
6-12 years: 0.3 ml (0.3 mg) intramuscularly. < 6 years: 0.15 ml (0.15 mg) intramuscularly |
Hypotension
Isolated hypotension
1. |
Elevate patient’s legs. |
2. |
Oxygen by mask (6-10 l/min). |
3. |
Intravenous fluid: rapidly, normal saline or Ringer’s solution. |
4. |
If unresponsive: adrenaline: 1:1,000, 0.5 ml (0.5 mg) intramuscularly, repeat as needed. In pediatric patients: 6-12 years: 0.3 ml (0.3 mg) intramuscularly. < 6 years: 0.15 ml (0.15 mg) intramuscularly. |
Vagal reaction (hypotension and bradycardia)
1. |
Elevate patient’s legs. |
2. |
Oxygen by mask (6-10 l/min). |
3. |
Atropine 0.6-1.0 mg intravenously, repeat if necessary after 3-5 min, to 3 mg total (0.04 mg/kg) in adults. In pediatric patients give 0.02 mg/kg intravenously (max. 0.6 mg per dose), repeat if necessary to 2 mg total. |
4. |
Intravenous fluids: rapidly, normal saline or Ringer’s solution. |
Generalized anaphylactoid reaction
1. |
Call for the resuscitation team. |
2. |
Suction airway as needed. |
3. |
Elevate patient’s legs if hypotensive. |
4. |
Oxygen by mask (6-10 l/min). |
5. |
Intramuscular adrenaline (1:1,000), 0.5 ml (0.5 mg) in adults. Repeat as needed. In pediatric patients: 6-12 years: 0.3 ml (0.3 mg) intramuscularly. < 6 years: 0.15 ml (0.15 mg) intramuscularly. |
6. |
Intravenous fluids (e.g. normal saline, Ringer’s solution). |
7. |
H1-blocker e.g. diphenhydramine 25-50 mg intravenously. |
A.1.4. Recording Acute Adverse Reactions
- Acute adverse reactions must be properly documented in the patient’s records, so that appropriate precautions can be taken before any future examination.
- All reactions requiring medical treatment should be recorded.
- Mild symptoms after contrast medium not requiring treatment should not be recorded. They may be unrelated to the contrast medium and caused by anxiety or by the patient’s disease. If such minor symptoms are recorded, the patient may in future be denied a clinically important enhanced examination.
- Full documentation of acute allergy-like reactions includes (a) measuring serum tryptase, preferably immediately after and 2 hours after the reaction, and (b) skin testing one month after the reaction to check for evidence of true allergy to the triggering contrast agent and for evidence of cross-reactivity to other agents.
A.1.5. Review of Treatment Protocols
Radiologists and their staff should review treatment protocols regularly (e.g. at 12 monthly intervals), so that each can accomplish their role efficiently. Knowledge, training, and preparation are crucial for guaranteeing appropriate and effective treatment if there is an adverse contrast-related event.
A.2. Late Adverse Reactions
Definition: |
A late adverse reaction to intravascular iodine-based contrast medium is defined as a reaction which occurs 1 h to 1 week after contrast medium injection. |
Reactions: |
Skin reactions similar in type to other drug-induced eruptions. Maculopapular rashes, erythema, swelling and pruritus are most common. Most skin reactions are mild to moderate and self-limiting.
A variety of late symptoms (e.g., nausea, vomiting, headache, musculoskeletal pains, fever) have been described following contrast medium, but many are not related to the contrast medium. |
Risk factors for skin reactions: |
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Management: |
Symptomatic and similar to the management of other drug-induced skin reactions e.g. antihistamines, topical steroids and emollients. |
Recommendations: |
Patients who have had a previous contrast medium reaction, or who are on interleukin-2 treatment should be advised that a late skin reaction is possible and that they should contact a doctor if they have a problem.
Patch and delayed reading intradermal tests may be useful to confirm a late skin reaction to contrast medium and to study cross-reactivity patterns with other agents.
To reduce the risk of repeat reaction, use another contrast agent than the agent precipitating the first reaction. Avoid agents which have shown cross-reactivity on skin testing.
Drug prophylaxis is generally not recommended.
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Note: Late skin reactions of the type which occur after iodine-based contrast media have not been described after gadolinium-based and ultrasound contrast media.
A.3. Very Late Adverse Reactions
Definition: An adverse reaction which usually occurs more than 1 week after contrast medium injection.
Type of reaction |
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Iodine-based contrast media |
Thyrotoxicosis. |
Gadolinium-based contrast media |
Nephrogenic systemic fibrosis. |
A.3.1. Thyrotoxicosis
Thyrotoxicosis |
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At risk |
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Not at risk |
Patients with normal thyroid function. |
Recommendations |
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A.3.2. Nephrogenic Systemic Fibrosis
A diagnosis of nephrogenic systemic fibrosis (NSF) should only be made if the Yale NSF Registry clinical and histopathological criteria are met (J Am Acad Dermatol 2011; 65: 1095-1106). The link between nephrogenic systemic fibrosis (NSF) and gadolinium-based contrast agents was recognized in 2006.
CLINICAL FEATURES OF NSF |
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Onset |
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Early changes |
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Later changes |
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End result |
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Patients |
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At higher risk |
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At lower risk |
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Not at risk of NSF |
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Measurement of renal function |
See B.1. |
CONTRAST AGENTS Risk classification (based on laboratory data) and Recommendations |
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Highest risk of NSF |
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Gadodiamide (Omniscan®) Ligand: Non-ionic linear chelate (DTPA-BMA) Gadopentetate dimeglumine (Magnevist® plus generic products) Ligand: Ionic linear chelate (DTPA) Gadoversetamide (Optimark®) Ligand: Non-ionic linear chelate (DTPA-BMEA)
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These agents are CONTRAINDICATED in
These agents should be used with CAUTION in patients with CKD 3 (GFR 30-60 ml/min) and in children less than 1 year old. There should be at least 7 days between two injections. Lactating women: Stop breastfeeding for 24 hours and discard the milk. Serum creatinine (eGFR) measurement and clinical assessment of patient before administration is mandatory. These agents should never be given in higher doses than 0.1 mmol/kg per examination in any patient. High-risk agents should be stored separately from intermediate and low risk agents to avoid use in error of a high-risk agent in a patient with poor renal function. |
Intermediate and lowest risk of NSF |
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Contrast agents:
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Gadobenate dimeglumine (Multihance®) Ligand: Ionic linear chelate (BOPTA) Special feature: It is a combined extracellular and liver specific agent with 2-3% albumin binding. In man ~4% is excreted via the liver. Gadofosveset trisodium (Vasovist®, Ablavar®) Ligand: Ionic linear chelate (DTPA-DPCP) Special feature: It is a blood pool agent with affinity to albumin (> 90%); 5% is excreted via the bile. Biological half-life is 12 times longer than for any other gadolinium-based contrast agent (18 hours compared to 1½ hours, respectively). Gadoxetate disodium (Primovist®, Eovist®) Ligand: Ionic linear chelate (EOB-DTPA) Special feature: It is an organ-specific gadolinium contrast agent with 10% protein binding and 50% excretion by hepatocytes.
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Gadobutrol (Gadovist®, Gadavist®) Ligand: Non-ionic cyclic chelate (BT-DO3A) Gadoterate meglumine (Dotarem®, Magnescope®) Ligand: Ionic cyclic chelate (DOTA) Gadoteridol (Prohance®) Ligand: Non-ionic cyclic chelate (HP-DO3A)
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These agents should be used with CAUTION in patients with CKD 4 and 5 (GFR < 30 ml/min). There should be at least 7 days between two injections. Pregnant women: These agents can be used to give essential diagnostic information. Lactating women: Discarding the breast milk in the 24 hours after contrast medium is not considered necessary, but the patient can discuss with the doctor whether she wishes to do this. Laboratory testing of renal function (eGFR) is not mandatory. |
Patients with NSF
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Gadolinium-based contrast media should only be used if the indication is vital and then only intermediate or low- risk agents should be used. |
Recommendations for all patients |
Never deny a patient a clinically well-indicated enhanced MR-examination. In all patients use the smallest amount of contrast medium necessary for a diagnostic result. Always record the name and dose of the contrast agent used in the patient records. |
Confounded cases: If two different gadolinium-based contrast agents have been injected, it is impossible to determine with certainty which agent triggered the development of NSF and the situation is described as ‘confounded’.
Unconfounded cases: The patient has never been exposed to more than one agent.