Radiology Life Support: Dealing with

Acute Contrast Reactions

William H. Bush, Jr., MD, FACR

University of Washington

Contrast Use

Test Yourself

Question # 1

A patient who has had a reaction to

iodinated contrast is at higher risk for

having a reaction to gadolinium agents.

True or False ?

Question # 2

Your patient is cool, clammy, and has

perspiration on their forehead and upper

lip. The reaction most likely occurring is:

1. Vagal reaction

2. Urticaria

3. Bronchospasm

Question # 3

Your patient complains of shortness of

breath. The most likely reaction occurring

is:

1. Vagal reaction with bradycardia

2. Urticaria

3. Bronchospasm

Question # 4

Which of these IMMEDIATE actions by you during

response to a major allergic-like systemic contrast

reaction is the most important ?

1. I.V. access

2. Airway / suction / oxygen

3. Cardiac monitor / pulse oximeter

4. Blood pressure

Question # 5

Which of these IMMEDIATE actions by you during

response to a major allergic-like systemic contrast

reaction is the least important ?

1. Talk to the patient

2. Take their pulse

3. Take their blood pressure.

Question # 6

The treatment for severe hypotension

and bradycardia is: (a, b or c)

a. IV fluids and atropine

b. IV fluids and epinephrine

c. Nitroglycerine

Question # 7

The key finding for diagnosing a vagal

reaction is: (a, b, c, or d)

a. Rapidity of breathing

b. Systolic blood pressure

c. Diastolic blood pressure

d. Pulse rate

Question # 8

The adult dose of IV atropine for treating

a vagal reaction is: (a, b, or c)

a. 5-10 mg

b. 1.0 mg

c. 0.3 mg

Question # 9

Initial treatment of laryngeal edema is:

(a, b, c, or d)

a. Atropine

b. Benadryl®

c. Beta-agonist inhaler

d. Epinephrine

Question # 10

Your patient is hypotensive; the most

effective route for epinephrine

administration is: (a or b)

a. Intravenously

b. Subcutaneously

Question # 11

Adult dosage of IV epinephrine for

treating a systemic anaphylaxis-like

contrast reaction is: (a or b)

a. 1 cc of 1:1,000

b. 1 cc of 1:10,000

Anticipate Potential Problems:

Chemotoxic effects of contrast

Anaphylaxis-like reactions

CONTRAST-INDUCED NEPHROTOXICITY

Gadolinium is not nephrotoxic if

given in usual does for MR imaging, e.g.

0.1 mmol/kg. However, in larger doses,

there is increased risk to the kidneys.

GADOLINIUM, ADVANCED RENAL FAILURE, and SYSTEMIC TOXICITY

Unresolved question of increased systemic toxicity to patients with advanced renal failure (e.g. GFR < 15cc/min) or on dialysis.

Theory of Nephrogenic Systemic Fibrosis (NSF): Free Gd triggers the process.

Three dialysis treatments removes 99% of

the gadolinium.

Questions of Your Patient

• Hemodialysis; advanced renal failure

• Previous reaction to contrast *-obtain specifics

• Asthma *• Allergies *

* Allergic reactions are more likely when these patient factors exist.

ACUTE, ANAPHYLACTIC-LIKE REACTIONS

from iodinated LOCM

Moderate, non-life-threatening:

0.2- 0.4% (1:250 injections)

Severe, life-threatening:

0.04% (1:2500 injections)

ACUTE, ANAPHYLACTIC-LIKE REACTIONS

with gadolinium agents

Very uncommon

Mayo Clinic: epinephrine was needed to

treat a serious reaction in 1:20,000

injections of a gadolinium agent.

PREMEDICATION

WHEN IS IT NECESSARY?

History of a few scattered hives: No

History of treatment for prior reaction: Yes

PREMEDICATION

Prednisone

50 mg, PO, q 6 h x 3 (e.g. 13, 7, 1 hr)

Diphenhydramine

50 mg, PO 1 hour before contrast

Greenberger and Patterson

J Allergy Clin Immunol

87:867-872, 1991

PREMEDICATION

Methylprednisolone (Medrol ®)

32 mg, PO, 12 and 2 hours before contrast

Diphenhydramine

50 mg, PO 1 hour before contrast

E. Lasser, et al

N.Engl.J.Med 1987; 317:845-9

PREMEDICATION

Corticosteroids: necessary to decrease

risk of contrast reactions needing

treatment

Antihistamines: alone are not adequate

PREMEDICATION

Corticosteroids are essential

Need minimum of 6 hours before contrast

(preferably longer)

** Reduces risk but does not eliminate it

Recognition & Treatment of

Systemic Reactions

Patient Presentations

• Uncomfortable

• Calm, poorly responsive to commands

• Anxious, agitated

Responding to a Possible Reaction

• Quickly assess the situation

• Call for help

• Remove the patient from the MR suite

(much of the emergency equipment

is not MR- compatible)

Responding to a Possible Reaction

• Take their pulse

• Talk with them

Responding to a Possible Reaction

• Taking their pulse:

1. Palpable: systolic is 80-90 mmHg

2. Rate: rapid or slow

Responding to a Possible Reaction

• Talking with the patient:

1. Assess for laryngeal edema

2. Assess degree of SOB

3. Assess responsiveness

Uncomfortable

• Skin reaction: Redness, itching,

hives

• Nausea & vomiting

Uncomfortable

• Skin reaction: Redness, itching,

hives

• Nausea & vomiting

• Plan: observation (may be first signs of a more serious reaction)

SERIOUS, LIFE-THREATENING REACTIONS

RESPONDING TO A SERIOUS REACTION

• Multiple tasks to accomplish

1. Airway / suction / oxygen2. Obtain pulse; I.V. access3. Leg elevation4. Provide medications5. Cardiac monitor / pulse

oximeter6. Obtain Blood pressure

• Take “ownership” of a task

Calm, Unresponsive

• Hypotension

• Hypoglycemia

HYPOTENSION

• With Tachycardia

• With Bradycardia

HYPOTENSION WITH TACHYCARDIA

• Leg elevation (approx. 60°)

• Oxygen by mask ( 6-10 L/min )

• IV fluids (normal saline or Ringer’s lactate)

Treatment includes:

HYPOTENSION WITH BRADYCARDIA

• Leg elevation (approx. 60°)

• Oxygen by mask ( 6-10 L/min )

• IV fluids ( normal saline or Ringer’s solution)

• Atropine IV

Treatment includes:

VAGAL REACTION

• Key finding = decreased pulse rate

ATROPINE

• Give if bradycardia is symptomatic

• Recommended dose:

• Adult IV dose range: 0.6-1.0 mg

• My preference: 1.0 mg as initial dose

Anxious, Agitated

• HYPOXIA (lack of oxygen)

ACUTE BRONCHOSPASM

Recommended treatment:

Beta-2 agonist inhaler

(2 - 3 puffs)

• Supplementary treatment:

Epinephrine

LARYNGEAL EDEMA

Goals: Oxygenation

Reduce edema of upper airway

Treatment: Oxygen by mask

Epinephrine, 1:10,000 IV

EPINEPHRINE: Route of Administration

• If hypotension is not significant –

can use I.M. or subcutaneous route

With significant Hypotension – Use IV

Epinephrine for I.V. use

EPINEPHRINE (Adrenalin)

INTRAVENOUS:

1:10,000 (1 mg in 10 ml)

10 ml = 1000 mcg

1 ml = 100 mcg

Start with 1 ml given slowly

(deliver the 100 mcg over 2-5 minutes)

EPINEPHRINE: Route of Administration

• If hypotension is not significant –

can use I.M. or subcutaneous route

EPINEPHRINE (Adrenalin)

SUBCUTANEOUS OR I.M. ( * if not

hypotensive )

1:1000 (1 mg in 1 ml)

1 ml = 1000 mcg

0.5 ml = 500 mcg

0.1 ml = 100 mcg

Start with 0.1 or 0.2 ml

EPINEPHRINE

PROBLEMS:

1. Not giving it

2. Giving it too late

3. Giving too much

4. Giving it so that it is not absorbed effectively

EPINEPHRINE

Recommended initial I.V. Dose:

1 ml of 1:10,000 epinephrine (100 mcgm) given slowly over 2 – 5 minutes

Additional amounts can be given if the

patient does not respond adequately

LARYNGEAL EDEMA

Beta-2 agonist inhaler: may make edema worse

Benadryl®: thickens secretions;

may cause hypotension

AD BEN RYL

PEDIATRIC REACTIONS

Children have good hearts

If a problem develops,

think AIRWAY

RESUSCITATION

Airway:

– clear, suction

– jaw lift

– oral airway

Ventilation:

– mouth-valve-mask

– bag-valve-mask (Ambu®)

OXYGEN IS GOOD !

( for all reactions )

OXYGEN

Nasal cannula:

2 – 6 L/min

provides only 25 – 40% concentration

Simple mask:

6 – 10 L/min

provides 35 – 60 % concentration

(Flow rate at least 6 L/min to prevent

carbon dioxide build-up in mask)

OXYGEN

• Via mask

• High flow rate

( 6 – 10 L / min. )

RESPONDING TO A SERIOUS REACTION

• Multiple tasks to accomplish

1. Airway / suction / oxygen2. Obtain pulse; I.V. access3. Leg elevation4. Provide medications5. Cardiac monitor / pulse

oximeter6. Obtain Blood pressure

• Take “ownership” of a task

QUIZ REVIEW

Answer to Question # 1

A patient who has had a reaction to

iodinated contrast is at higher risk for

having a reaction to gadolinium agents.

True or False ?

(depending on the prior reaction, consider premedication for the gadolinium study)

Answer to Question # 2

Your patient is cool, clammy, and has

perspiration on their forehead and upper

lip. The most likely reaction occurring is:

1. Vagal reaction

2. Urticaria

3. Bronchospasm

Treatment: I.V. fluids + atropine

Answer to Question # 3

Your patient complains of shortness of

breath. The reaction most likely occurring

is:

1. Vagal reaction with bradycardia

2. Urticaria

3. Bronchospasm

Treatment: Beta-2 agonist inhaler; epinephrine

Answer to Question # 4

Which of these IMMEDIATE actions by you during

response to a major allergic-like systemic contrast

reaction is the most important ?

1. I.V. access

2. Airway / suction / oxygen

3. Cardiac monitor / pulse oximeter

4. Blood pressure

Answer to Question # 5

Which of these IMMEDIATE actions by you during

response to a major allergic-like systemic contrast

reaction is the least important ?

1. Talk to the patient

2. Take their pulse

3. Take their blood pressure.

Answer to Question # 6

The treatment for severe hypotension andbradycardia is: (a, b, or c)

a. IV fluids and atropineb. IV fluids and epinephrinec. Nitroglycerine

Answer to Question # 7

The key finding for diagnosing a vagal

reaction is: (a, b, c, or d)

a. Rapidity of breathing

b. Systolic blood pressure

c. Diastolic blood pressure

d. Pulse rate

Answer to Question # 8

The adult dose of IV atropine for treating a

vagal reaction is: (a, b, or c)

a. 5-10 mg

b. 1.0 mg

c. 0.3 mg

Answer to Question # 9

Initial treatment of laryngeal edema is:

(a, b, c, or d)

a. Atropine

b. Benadryl®

c. Beta-agonist inhaler

d. Epinephrine

Answer to Question # 10

Your patient is hypotensive; the most

effective route for epinephrine

administration is: (a or b)

a. Intravenously

b. Subcutaneously

Answer to Question # 11

Adult dosage of IV epinephrine for

treating a systemic anaphylaxis-like

contrast reaction is: (a or b)

a. 1 cc of 1:1,000

b. 1 cc of 1:10,000

THANK YOU