The document summarizes safety aspects of contrast media used in medical imaging. It discusses ideal properties of contrast media including iodine being well-suited due to its atomic number and excretion through kidneys. It also covers physiology of administration and excretion, potential toxicities including reactions to hyperosmolality, chemicals and immunologically. Treatment approaches for different types and severities of reactions like hives, bronchospasm and hypotension are provided.

1. SAFETY ASPECTS
OF CONTRAST MEDIA
SWAPNIL SHETTY. 1ST YEAR MSc. MIT. MCHP. MAHE.

2. INTRODUCTION
• Contrast materials, also called contrast agents or contrast media, are
substances used to enhance the visibility of internal structure in the image
produced by x-rays, computed tomography (CT), magnetic resonance (MR)
imaging and ultrasound.
• Allows visualization of structures that can not be seen well or at all under
normal circumstances.
• Enhance subject contrast in a tissue that normally has low subject contrast
and provide better delineation of the adjacent anatomic structures

3. IDEAL CONTRAST MEDIA
• High water solubility.
• Biological inertness (non antigenic).
• Low viscosity.
• Low or iso-osmolar to plasma.
• Selective excretion, like excretion by kidney is favorable.
• Reasonable cost.
• LD50 should be high.

4. WHY IODINE?
• High atomic number : 53 and atomic weight:127.
• Total iodine content in the body 50 mg.
• High contrast density.
• Allows firm binding to highly variable benzene ring.
• Low toxicity.
• Easily excreted through renal route.

5. CHOICE OF CONTRAST MEDIA
• Effects on RBC should be less or mild
• Should be less neurotoxic.
• Should show less or no incidence of allergic reactions.
• Minimal pain and heat sensation. (Minimal patient motion)
• Lesser endothelial damage thus reduce BBB damage.
LOW OSMOLAR NON-IONIC CONTRAST

6. PHYSIOLOGY
• Concentration and excretion of these contrast media is predominantly
by passive glomerular filtration. Net tubular excretion and protein
binding is negligible in the dose used. Liver and Intestine excrete 1%
of the compounds.
• After intravascular administration, first it diffuses into the
extravascular space and is simultaneously excreted. Then the
equilibrium is reached between the intra and the extravascular space.
• Continued excretion and reentry of contrast media from E.C.F. to
I.C.F. leads to decrease in the plasma level. Plasma has the half life of
30-60 min.

7. • Contrast media are filtered from blood into the Bowman’s capsule by
passive glomerular filtration. In the Bowman’s capsule, plasma
concentration of contrast media is same as in the blood.
• In PCT, reabsorption of Na and H2O causes 5-10 times concentration
of contrast media. If the patient is on diuretics, the concentration does
not occur.
• Further increase in the concentration of contrast media occurs by
counter current mechanism in the loop of Henle. In DCT by the action
of ADH, the concentration of contrast media further increases.

8. TOXICITY
• Reactions unrelated to contrast media.
• Hyperosmolality.
• Chemotoxic.
• Immunological.

9. Reactions unrelated to contrast media
1. Pyrogenic (Unsterile injections).
• Stop injection.
• Reassure the patient.
• Cover the patient with blanket.
• No need for medication.
2. Vasovagal especially in anxious or psychosomatic patients.
3. Hypertensive attacks in patients with pheochromocytoma.
4. Excessive dehydration, hypoglycemia.

10. Hyperosmolality
• This is due to the high osmolarity of contrast media than plasma. The
reactions include:
a. Erythrocyte damage.
b. Capillary endothelial damage.
c. Vasodilatation.
d. Hypervolemia.
e. Cardiovascular effects.
f. Vascular pain.
g. Disturbance of BBB.

11. Chemotoxic
Chemotoxic effects are usually due to the cations. Especially Na+. The
effects are seen in:
i. Neurons.
ii. Myocardial cells.
iii. Capillary endothelium.
iv. RBC.
v. Kidney.
Nephrotoxicity of contrast media is due to
• Decreased renal perfusion. (low B.P., peripheral vasodilatation).
• Glomerular injury – manifest as proteinuria.Tubular injury.
• due to osmolarity, chemotoxicity, ischaemia.
• Contrast media precipitation of Tamm Horsfall proteins that block tubules.
• Swelling of renal tubular cells causing obstruction.

12. Immunological (Allergic) Toxicity
Mechanisms
• Deactivation of angiotensin converting enzyme. Incidence of adverse
contrast media reactions to intra-arterial injection is about 1/3rd of
incidence following intravenous injection because the latter stimulate
release of vasoactive substances from mast cells or deactivates ACE in
lung. ACE deactivates bradykinin, the concentration of which rises
with IV injection of contrast media.
• Due to damage to the endothelium which initiates the activation
system which inturn may be responsible for many adverse
anaphylactoid reactions.

13. • Activation of complement, kinins, coagulation and fibrinolytic
systems.
• Inhibition of cholinesterase with consequent vagal over stimulation →
acetylcholine release → collapse, bradycardia, bronchospasm.
• Release of vasoactive substances like histamine, bradykinin, serotonin.

14. Anaphylactic Reaction
• Occurs in previously sensitized individual.
Anaphylactoid Reaction
• Occurs in non sensitized individual.

15. Contrast induced nephropathy
• Contrast-induced nephropathy (CIN) is defined as the impairment of
kidney function—measured as either a 25% increase in serum
creatinine (SCr) from baseline or a 0.5 mg/dL (44 µmol/L) increase in
absolute SCr value—within 48-72 hours after intravenous contrast
administration.
• Hydration therapy, typically with intravenous saline, is the cornerstone
of contrast-induced nephropathy (CIN) prevention. However, other
agents have demonstrated some benefit in prevention of CIN,
including N-acetylcysteine (NAC) and statins.

16. Effects of Metformin
• Metformin is a antidiabetic drug is prescribed widely. The drug is
usually administered to control type II diabetes mellitus.
• One of the most important side effects of metformin is the possibility
of lactate accumulation and occurrence of metformin associated lactic
acidosis (MALA), which develops under various circumstances
including decreased renal function or concurrent use of toxic agents.
• intravascular injection of iodinated contrast agents for radiologic
purposes may result in kidney injury, it is suggested that metformin
should be held in diabetic patients with renal failure before
administration of contrast media and not to be taken by the patient
again till 48 hours after the procedure and assessment of kidney
function which should be normal.

17. REACTIONS OF CONTRAST MEDIA
• Contrast materials are safe drugs.
• While serious allergic or other reactions to contrast materials are rare,
radiology departments are well-equipped to deal with them.
• Adverse reactions occurring due to contrast media are
1. Mild
2. Moderate
3. Severe
• Adverse reactions ranging from mild to severe do occur but severe
reactions are very uncommon.

18. ADVERSE REACTIONS
MILD
(5%)
MODERATE
(1%)
SEVERE
(0.05%)
1. Urticaria
2. Pruritis
3. Rhinorrhea
4. Nausea
5. Vomiting
6. Cough
1. Persistent –
vomiting
2. Diffuse urticaria
3. Facial edema
4. Mild bronchospasm
5. Palpitations
6. Bradycardia
7. Hypertension
8. Abdominal cramps
1. Arrhythmias
2. Hypotension
3. Bronchospasm
4. Laryngeal edema
5. Pulmonary edema
6. Seizures
7. Syncope
8. Death

19. Patients in high risk group for reaction.
• Previous reaction to CM.
• Asthma.
• Previous allergic reaction.
• Renal insufficiency GFR < 30 ml/min , serum creatinine > 1.6mg/dL.
• DM , metformin drug.
• Old age , cardiovascular disease.
• Thyrotoxicosis ,myasthenia gravis.
• Pheochromocytoma, sickle cell disease.

20. BASIC RULES FOR TREATMENT
• Never leave the patient unattended at least for an hour.
• Monitor the patient at least 20 min after contrast agent administration.
• Room should be stocked with appropriate Basic and Advanced life
support and monitoring equipment & drugs

21. OXYGEN
CORTICOSTEROIDSEPINEPHRINE

22. Treatment of Acute Reactions to Contrast Media
HIVES (Urticaria)
Treatment Dosing
Mild (scattered and/or transient) No treatment often needed; however, if
symptomatic, can consider:
Diphenhydramine (Benadryl®)* 25–50 mg PO
= or
Fexofenadine (Allegra®)** 180 mg PO
Moderate (more numerous/bothersome) Monitor vitals
Preserve IV access
Consider diphenhydramine (Benadryl®)* 25–50 mg PO
or
Fexofenadine (Allegra®}&
180 mg PO
or
Consider diphenhydramine (Benadryl®)* 25–50 mg IM or IV (administer
IV dose slowly over 1–2 min)

23. Severe (widespread and/or
progressive)
Monitor vitals
Preserve IV access
Consider Diphenhydramine (Benadryl®)* 25–50 mg IM or IV
(administer IV dose slowly
over 1–2 min)
* Note: all forms can cause drowsiness;
IM/IV form may cause or worsen
hypotension
& Note: second generation antihistamines cause less
drowsiness; may be beneficial for patients who
need to drive themselves home

24. DIFFUSEERYTHEMA
Treatment Dosing
All forms Preserve IV access
Monitor vitals
Pulse oximeter
O2 by mask 6–10 L / min
Normotensive No other treatment usually needed
Hypotensive IV fluids 0.9% normal saline 1,000 mL rapidly
or
Lactated Ringer’s 1,000 mL rapidly

25. If profound or unresponsive to fluids alone
can also consider
Epinephrine (IV)* IV 1 mL of 1:10,000 dilution
(0.1 mg); administer slowly
into a running IV infusion of
fluids; can repeat every few
minutes as needed up to 10
mL (1 mg) total
or (if no IV access available)
Epinephrine (IM)* IM 0.3 mL of 1:1,000 dilution
(0.3 mg); can repeat every 5-15
minutes up to 1 mL (1 mg)
total
or
Epinephrine auto-injector
(EpiPen® or equivalent)
(0.3 mL of 1:1,000 dilution,
fixed[0.3mg]); can repeat
every 5-15 minutes up to three
times
Consider calling emergency response
team or 911

26. Treatment Dosing
All forms Preserve IV access
Monitor vitals
Pulse oximeter
O2 by mask 6–10 L / min
Mild Beta agonist inhaler (Albuterol®) 2 puffs (90 mcg/puff) for a total of
180 mcg; can repeat up to 3 times
Consider sending patient to the Emergency
Department or calling emergency response team
or 911, based upon the completeness of the
response to the beta agonist inhaler
BRONCHOSPASM

27. Treatment Dosing
Modera
te
Beta agonist inhaler (Albuterol®) 2 puffs (90 mcg/puff) for a total of 180 mcg; can
repeat up to 3 times
Consider adding epinephrine (IM)* IM 0.3 mL of 1:1,000 dilution (0.3 mg); can repeat
every 5-15 minutes up to 1 mL (1
mg) total
or
Epinephrine auto-injector (EpiPen® or equivalent)
(0.3 mL of 1:1,000 dilution, fixed[0.3mg]); can repeat
every 5-15 minutes up to three times
or
Epinephrine (IV)* IV 1 mL of 1:10,000 dilution (0.1 mg); administer
slowly into a running IV infusion of fluids or use
saline flush;
can repeat every few minutes as needed up to 10 mL
(1 mg) total
Consider calling emergency response team or
911 based upon the completeness of the
response

28. Severe Epinephrine (IV)* IV 1 mL of 1:10,000 dilution (0.1 mg); administer
slowly into a running IV infusion of fluids or
slow IV push followed by a slow saline flush; can
repeat every few minutes as needed up to 10 mL
(1 mg) total
or
Epinephrine (IM)* IM 0.3 mL of 1:1,000 dilution (0.3 mg); can
repeat every 5-15 minutes up to 1 mL
(1 mg) total
or
Epinephrine auto-injector (EpiPen® or
equivalent) (0.3 mL of 1:1,000 dilution,
fixed[0.3mg]); can repeat every 5-15 minutes up
to three times

29. LARYNGEAL EDEMA
Treatment Dosing
All forms Preserve IV access
Monitor vitals
Pulse oximeter
O2 by mask 6–10 L / min
Epinephrine (IV)* IV 1 mL of 1:10,000 dilution (0.1 mg);
administer slowly into a running IV
infusion of fluids or use saline flush;
can repeat every few minutes as needed
up to 10 mL (1 mg) total
or

30. Epinephrine (IM)* IM 0.3 mL of 1:1,000 dilution (0.3 mg);
can repeat every 5-15 minutes up to 1
mL
(1 mg) total
or
Epinephrine auto-injector (EpiPen® or
equivalent)
(0.3 mL of 1:1,000 dilution,
fixed[0.3mg]); can repeat every 5-15
minutes up to three times
Consider calling emergency response
team or 911 based upon the severity
of the reaction and the completeness
of the response
*e:Ninothypotensive patients, the preferred
route of epinephrine delivery is IV, as the
extremities may not be perfused
sufficiently to allow for adequate
absorption of IM administered drug.

31. Treatment Dosing
All forms Preserve IV access
Monitor vitals
Pulse oximeter
O2 by mask 6–10 L / min
Elevate legs at least 60 degrees
IV fluids: 0.9% normal saline 1,000 mL rapidly
or
Lactated Ringer’s 1,000 mL rapidly
HYPOTENSION

32. Hypotension with bradycardia (pulse < 60 bpm) (Vasovagal reaction)
Ifmild No other treatment usuallynecessary
Ifsevere
(patient remains symptomatic despiteabove
measures)
In addition to above measures: Atropine
(IV)
0.6 – 1.0 mg; administer into a running IV infusion
offluids; can repeat up to 3 mg total
Consider calling the emergency response team
or911
Hypotension with tachycardia (pulse > 100 bpm) (Anaphylactoid reaction)
If hypotensionpersists Epinephrine (IV)* IV 1 mL of 1:10,000 dilution (0.1 mg); administer
slowly into a running IV infusionof fluids; can
repeat every few minutes as needed up to 10 mL (1
mg) total
or
Epinephrine (IM)* IM 0.3 mL of 1:1,000dilution (0.3 mg); can repeat
every 5-15 minutes up to 1 mL
(1 mg) total
or
Epinephrine auto-injector (EpiPen® or equivalent)
(0.3 mL of 1:1,000 dilution, fixed[0.3mg]); can repeat
every 5-15 minutes up to three times
Consider calling emergency response team or
911 based upon the severity of the reaction and
the completeness of the response
*e:Ninothypotensivepatients, the preferred route of
epinephrine delivery is IV, as the extremities may not be
perfused sufficiently to allow for adequate absorption of
IM administered drug.

33. HYPERTENSIVE CRISIS
Treatment Dosing
All forms Preserve IV access
Monitor vitals
Pulse oximeter
O2 by mask 6–10 L / min
Labetalol (IV) 20 mg IV; administer slowly, over
2 min; can double the dose every
10 min (e.g., 40 mg 10 min later,
then 80 mg 10 min after that)
or (if labetalol not available)
Nitroglycerin tablet (SL) 0.4 mg tablet; can repeat every 5 –
10 min
and
Furosemide (Lasix®) (IV) 20 – 40 mg IV; administer
slowly over 2 min
Call emergency response team or 911

34. Treatment Dosing
Preserve IV access
Monitor vitals
O2 by mask 6–10 L / min
Pulse oximeter
Elevate head of bed, if
possible
Furosemide (Lasix®) 20–40 mg IV;
administer
slowly over 2
min
Call emergency response
team or 911
Treatment Dosing
Diagnosis of exclusion
Assess patient for developing
signs and symptoms that
might indicate another type
of reaction
Preserve IV access
Monitor vitals
Pulse oximeter
If no identifiable
manifestations and normal
oxygenation, consider this
diagnosis
Reassure patient
ANXIETY(PANICATTACK)PULMONARY EDEMA

35. SEIZURES/CONVULSIONS
Treatment Dosing
Observe and protect the patient
Turn patient on side to avoid aspiration
Suction airway, as needed
Preserve IV access
Monitor vitals
Pulse oximeter
O2 by mask 6–10 L / min
If unremitting Call emergency response team or 911
Lorazepam (IV) IV 2–4 mg IV; administer slowly, to maximum
dose of 4 mg

36. HYPOGLYCEMIA
Preserve IV access
O2 by mask 6–10 L / min
If patient is able to
swallow safely
Oral glucose Two sugar packets or 15 g of
glucose tablet/gel or ½ cup (4
oz) of fruit juice
If patient is unable to
swallow safely and IV
access available
Dextrose 50% (IV) D50W 1 ampule (25 grams) IV
administer over 2 min
D5W or D5NS (IV) as
adjunct therapy
Administer at a rate of 100
mL/hour
If no IV access is
available
Glucagon (IM) IM 1 mg

37. Drugs used in our department.
• Atropine
• Adrenaline/Epinephrine
• Hydrocortisone
• Morphine
• Nor-adrenaline
• Dextrose
• Avil
• diphenhydramine
• Albuterol
• Aminophylline
• Furosemide
• Diazepam
• Nitroglycerine
• Nifidipine
• Pentolamine

38. • Calcium gluconate
• Soda bicarbonate
• Xylocard
• Dopamine

39. reference
• Radiological Procedures – A Guideline by Dr.Bhushan N Lakhkar.
• http://nephropathol.com/Article/jnp-10894
• https://pubmed.ncbi.nlm.nih.gov/9640281/
• https://emedicine.medscape.com/article/246751-overview

40. THANK YOU