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Contrast Reactions and Other
Emergencies in the Radiology
Department: What the Radiologist
Needs To Know
Arden Lee, PGY-5
Radiology Grand Rounds
September 4, 2013
Pre-Quiz
1. A patient experiences an acute adverse
contrast reaction. Symptoms include facial
swelling and stridor. What is the first medication
that should be administered?
a. Benadryl
b. Epinephrine
c. Corticosteroid
d. Atropine
Pre-Quiz
2. The correct dose/route/concentration of
epinephrine that should be administered in the
setting of an acute allergic contrast reaction is:
a. 1 mg, IV, 1:10,000
b. 0.3 mg, IV, 1:1,000
c. 0.3 mg, IM, 1:1,000
d. 1 mg, IM, 1:10,000
Pre-Quiz
3. A patient experiences an acute adverse
reaction during a CT scan. Symptoms include
diaphoresis, hypotension and bradycardia. What
medication should be administered?
a. Benadryl
b. Epinephrine
c. Corticosteroid
d. Atropine
Pre-Quiz
4. A patient in the Radiology department
suddenly becomes pulseless and unresponsive.
You initiate CPR. What is the appropriate rate of
compressions:breaths?
a. 15:2
b. 15:1
c. 30:2
d. 100:2
Pre-Quiz
5. According to the 2010 American Heart
Association Basic Life Support guidelines, what is
the first step when encountering an
unresponsive person?
a. Open airway
b. Provide rescue breaths
c. Perform chest compressions
d. Activate emergency response system
Pre-Quiz
6. According to the 2010 American Heart
Association Basic Life Support guidelines, what is
the second step when encountering an
unresponsive person?
a. Open airway
b. Provide rescue breaths
c. Perform chest compressions
d. Activate emergency response system
Outline
• Recognize and manage acute adverse contrast
reactions
• Types of adverse contrast reactions
• Pre-medication of contrast reactions
• Other emergencies including interstitial
extravasation of contrast and unresponsive
patient
• Contrast in breastfeeding and lactating
women
Importance
• A recent telephone survey of Radiologists in
Canada/US showed that only 41% knew the
correct dose and route of administration of
epinephrine
• Radiologists’ knowledge of acute management
of contrast reactions is deficient
ACUTE ADVERSE REACTIONS TO
CONTRAST MEDIA
Iodinated contrast
• Significant decrease in adverse reactions since
shifting from high osmolality contrast to nonionic low osmolality contrast
• Frequency of acute adverse reactions to
contrast is now estimated at 3%
• The vast majority of these are very mild and
require no treatment
Iodinated contrast
• The rate of severe reactions is 1 in 2,500
(0.04%)
• The rate of death from contrast injection is
estimated at 1 in 170,000
Risk Factors
• Prior allergic-like reaction to contrast
increases risk by 10-35%
• Atopic individuals
• Asthma history
• No known effects of dose, route, and rate of
delivery of contrast on allergic reactions
Risk Factors
• Pheochromocytoma, paraganglioma,
thyrotoxicosis, dysproteinemias, sickle cell
disease
• No data to support specific precautions in
these patients
Risk Factors
• Myasthenia gravis
• One recent study suggested that intravascular
contrast may exacerbate symptoms,
suggesting that MG is a relative
contraindication
• No definitive recommendation at this time
Gadolinium
• Frequency of adverse reactions is 0.07% to
2.4%
• Vast majority of these are very mild
physiological reactions
• Allergic-like reactions are rare, ranging in
frequency from 0.004% to 0.7%
• Severe anaphylactic reactions are exceedingly
rare (0.001-0.01%)
Case 1
A 56 year old female is scanned in McCaig Tower
at 12 am to rule out acute diverticulitis. The CT
tech phones you and states that the patient is
experiencing dyspnea, urticaria, and facial
swelling. What do you do?
Assess the patient
•
•
•
•
•
ABC’s
Vital signs
Physical exam
Recognize the contrast reaction
Initiate appropriate management
Types of Reactions
• Allergic-like or Physiologic
• Mild, moderate, or severe
Classification
Allergic-like
Physiologic
Urticaria
Diffuse erythema
Angioedema (facial edema)
Laryngeal edema
Bronchospasm
Anaphylactic shock (hypotension +
tachycardia)
Nausea/vomiting
Flushing/warmth/chills
Anxiety
Hypertensive emergency
Seizures
Vasovagal reaction (hypotension +
bradycardia)
Allergic-Like Reactions
• Urticaria
– Raised red skin wheals and pruritis
• Erythema
– Diffuse skin redness
Allergic-Like Reactions
• Angioedema
– Swelling of face and lips
– Often heralds more significant laryngeal edema
• Laryngeal edema
– Serious, life threatening condition
– Anxious patient
– Stridor, coughing, hoarseness, feeling of lump in
throat
Allergic-Like Reactions
• Bronchospasm
– Resembles asthma attack and patients may have
history of asthma attacks
– Anxious patient
– Wheezing, shortness of breath
Allergic-Like Reactions
• Anaphylactic reaction
– Acute, generalized, systemic symptoms
– May have some or all of the above symptoms,
including hives, skin redness, angioedema, airway
narrowing, and hypotension with tachycardia
– Life-threatening
MANAGEMENT OF ALLERGIC-LIKE
CONTRAST REACTIONS
ANAPHYLAXIS
ALGORITHM
FOR ADULTS
Assessment: ABC’s and
vital signs
IV access
100% O2 by mask
Monitor, pulse oximeter
Systemic symptoms
Hypotensive (SBP < 90)
Tachycardic (HR > 100)
Epinephrine
IM: 0.3 mg (0.3 mL of 1:1,000)
Repeat q5-15 min up to 1 mg total dose
IV: 0.1 mg (1 mL of 1:10,000)
Administer slowly into a running saline
infusion over 2-3 min
Repeat q5-10 min up to 1 mg total dose
IV fluids: 1 L rapid bolus
normal saline
Activate emergency
response team
Epinephrine
• IV > IM in setting of hypotension because
decreased perfusion of the extremities may limit
absorption of intramuscular epinephrine
• However, if administered incorrectly, epinephrine
can cause fatal cardiac arrhythmias
• IM is safer than IV in inexperienced hands
• IM > IV due to better safety margin and ease of
use
• IM administration in the anterolateral thigh
• IM > SC due to better absorption
Other medications?
• Antihistamines
– used primarily for the treatment of urticaria
without other systemic symptoms
– can exacerbate hypotension and thicken airway
secretions
– should not be used if there are airway symptoms
or hypotension
Other medications?
• Corticosteroids
– no role in acute management
– administered after resuscitation and stabilization
to prevent secondary delayed reaction
– Methylprednisolone (Solumedrol) 40 mg IV over 2
min
OR
– Hydrocortisone (Solucortef) 200 mg IV over 2 min
ALLERGIC
ALGORITHM
Assessment and vital
signs
Activate emergency
response team
*normal BP
IV access
100% O2 by mask
Monitor, pulse oximeter
Bronchospasm
Laryngeal edema
Benadryl 25-50 mg
PO (mild)
IM/IV (severe)
Beta agonist inhaler
2 puffs
no response
Urticaria/
Erythema
Epinephrine
IM: 0.3 mg (0.3 mL of 1:1,000)
Can repeat up to 1 mg total
no response
Case 2
A 23 yo male is scheduled to have a MR
arthrogram of the right shoulder. Upon seeing
the needle, he immediately becomes
diaphoretic and light-headed.
How do you respond?
Assess the patient
•
•
•
•
•
ABC’s
Vital signs
Physical exam
Recognize the reaction
Initiate appropriate management
Classification of reactions
Allergic-like
Physiologic
Urticaria
Diffuse erythema
Angioedema (facial edema)
Laryngeal edema
Bronchospasm
Anaphylactic shock (hypotension +
tachycardia)
Nausea/vomiting
Anxiety
Pulmonary edema
Hypertensive emergency
Seizures
Vasovagal reaction (hypotension +
bradycardia)
Vasovagal reaction
• Relatively common physiologic reaction
characterized by hypotension with
bradycardia
VASOVAGAL
ALGORITHM
Activate emergency
response team
Assessment: ABC’s and
vital signs
IV access
100% O2 by mask
Monitor, pulse oximeter
1. Trendelenburg position – elevate legs by
60 degrees
2. IV fluids – 1 L rapid bolus normal saline
MILD
No other treatment necessary
SEVERE,
BRADYCARDIC
Atropine 0.6-1.0 mg IV
administered slowly, followed
by saline flush
Repeat q3-5 min, up to 3 mg
total
Physiologic reactions
• Hypertensive emergency
– Diastolic BP > 120 mm Hg or systolic BP > 200 mm
Hg
– Headache, nausea
– Obtunded or confused
– May develop seizures
• Pulmonary edema
• Angina
CARDIOVASCULAR
ALGORITHM
Assessment: ABC’s and
vital signs
Activate emergency
response team
IV access
100% O2 by mask
Monitor, pulse oximeter
HYPERTENSION
SBP > 200 mm Hg
DBP > 120 mm Hg
PULMONARY EDEMA
ANGINA
Labetalol 20 mg IV
Administer slowly over 2
min
Elevate head of bed
Nitroglycerin 0.4 mg SL
Morphine 2 mg IV
Nitroglycerin 0.4 mg SL
Furosemide 20-40 mg IV
(administer slowly over 2
min)
Furosemide 20-40 mg IV
(administer slowly over 2
min)
Morphine 2 mg IV
Case 3
18 yo male sent for CT head for seizures. While
on the CT table, the patient starts seizing again.
The CT technologists call you in a panic. What
do you do?
SEIZURES
ALGORITHM
Assessment: ABC’s and
vital signs
• Protect patient, clear area
• Turn patient on side to
avoid aspiration
• Suction airway as needed
IV access
100 % O2 by mask if not
vomiting
UNREMITTING
SEIZURE
Lorazepam IV 2-4 mg,
administered slowly, max dose
of 4 mg
Activate emergency
response team
Hypoglycemia
•
•
•
•
NPO prior to exam
Diabetics
Patients feel weak, dizzy or lightheaded
Patient looks pale or diaphoretic
HYPOGLYCEMIA
ALGORITHM
Assessment: ABC’s and
vital signs
Activate emergency
response team
IV access
100% O2 by mask
Monitor, pulse oximeter
HYPOGLYCEMIA
Oral glucose
Juice
Glucose tablet/gel 15 g
Patient can’t swallow
No IV access
D50W 1 ampule (25 g) IV
Administer slowly over 2
min
Glucagon 1 mg IM
McCaig CT control room
SSB CT control room
“We found no relevant evidence. We are
therefore unable to make recommendations
about H1-antihistamine use in the treatment of
anaphylaxis.”
“We conclude that there is no evidence from
high-quality studies for the use of steroids in the
emergency management of anaphylaxis.
Therefore, we can neither support nor refute the
use of these drugs for this purpose.”
PREMEDICATION OF PATIENTS AT
RISK FOR CONTRAST REACTION
Case 4
45 yo male previously had a mild allergic
reaction to contrast (hives). He needs a contrast
enhanced CT scan to evaluate an adrenal mass.
He can not have an MRI due to previous metal
working injury.
Can he have the CT scan?
Premedication for contrast allergies
• Evidence suggests a decrease in overall
adverse events after steroid premedication
• However, the benefit is mainly in reduction of
the minor contrast reactions that require no
or little treatment
• No evidence that premedication protects
against severe, life threatening adverse
reactions
Premedicaton strategy
Elective
Emergent
Prednisone 50 mg PO before contrast
injection:
- 13 hours before
- 7 hours before
- 1 hour before
Solumedrol 40 mg IV
Every 4 hours until injection
OR
OR
Solucortef 40 mg IV
Every 4 hours until contrast study
Methylprednisolone 32 mg PO before
contrast injection:
- 12 hours before
- 2 hours before
AND
AND
Benadryl 50 mg IV/IM/PO
1 hour before
Benadryl 50 mg IV
1 hour before
Premedication
• Elective administration of steroids is preferred
• In the emergent setting, IV steroids should be
administered at least 4-6 hours before
contrast injection
• No benefit of administering steroids less than
4 hours before injection
Breakthrough reactions
• Even with premedication, adverse reactions
can “break through”
• Breakthrough reactions are usually similar in
nature and severity to the index reaction
• Patients with a mild index reaction are unlikely
to develop a severe breakthrough reaction
• Patients who had a severe index reaction are
at high risk for a severe breakthrough reaction
OTHER EMERGENCIES
Case 5
35 yo female is having a CT scan to rule out
acute appendicitis. During the injection, the
patient complains of severe burning pain in the
forearm at the injection site. The technologists
stop the injection and notice marked edema and
erythema at the injection site. What do you do?
Incidence
• Reported incidence ranges from 0.1% to 0.9%
• Of these, > 95% have no or minimal adverse
effects
• Frequency of extravasation is unrelated to
catheter location, catheter size, or injection
rate
Interstitial extravasation of contrast
• Extravasated iodinated contrast is toxic to
surrounding tissues, particularly the skin
• Produces a local inflammatory response
• Usually resolves after 24-48 hours
• Most patients recover without significant
injury
Serious complications
• The most common serious adverse
complication from interstitial extravasation is
compartment syndrome
• Other potential serious complications include
skin ulceration and tissue necrosis
• The volume of extravasation does not
necessarily predict the severity of injury
Serious complications
• Signs of a serious complication:
– Progressive swelling or pain
– Altered tissue perfusion (decreased capillary refill)
– Change in sensation
– Skin ulceration or blistering
Serious complications
• Some patients are at increased risk
– Arterial insufficiency (atherosclerosis, diabetic)
– Compromised venous or lymphatic drainage
– Extravasations occurring in dorsum of hand, foot
or ankle
Treatment
• No clear consensus regarding effective
treatment
• No clear evidence favoring cold or warm
compresses
• No role for attempted aspiration of
extravasated contrast
• Close clinical follow-up required for several
hours as the severity of the reaction is difficult
to assess based on initial evaluation
Assessment and vital
signs
EXTRAVASATION
ALGORITHM
Examine affected limb, check distal
pulses, capillary refill, motor function
and sensation
- Elevate affected extremity
- Cold or warm compresses (no
evidence)
- Analgesia
HIGH CLINICAL
CONCERN*
Surgical consultation
LOW CLINICAL
CONCERN
Clinical follow-up required
*Progressive swelling or pain, altered tissue perfusion (decreased capillary refill), change in
sensation, skin ulceration or blistering
Case 6
A 65 yo male is having a CTA of the abdomen to
R/O abdominal aortic aneurysm. The injection
malfunctions and a large quantity of air is
injected. The man develops dyspnea and chest
pain. What do you do?
Air embolism
• A rare but potentially fatal complication of IV
contrast injection
Treatment
• Patient should be placed in left lateral
decubitus position to trap air in right atrium
• Administer 100% oxygen
AIR EMBOLISM
ALGORITHM
Assessment: ABC’s and
vital signs
Place patient in left lateral
decubitus position
100% O2 by mask
Activate emergency
response team
Case 7
• A 75 yo female is brought to the CT scanner.
She suddenly becomes unresponsive. You are
the lone resident/radiologist. What do you
do?
BLS healthcare provider algorithm.
Berg R A et al. Circulation 2010;122:S685-S705
Copyright © American Heart Association
Key Changes in the 2010 guidelines
• Immediate recognition of sudden cardiac arrest based
on assessing unresponsiveness and absence of normal
breathing (ie, the victim is not breathing or only
gasping)
• “Look, Listen, and Feel” removed from the BLS
algorithm
• Sequence change to chest compressions before rescue
breaths (CAB rather than ABC)
• Encouraging Hands-Only (chest compression only) CPR
(ie, continuous chest compression over the middle of
the chest) for the untrained lay-rescuer
• Tap patient on shoulder and shout at them
• Check for no breathing or abnormal
breathing, e.g. gasping
• Gasping is NOT adequate breathing
• Call a Code Blue
• Studies show that health care providers spend
too long checking for pulse
• Spend only 10 seconds checking for a pulse – if
no definite pulse, start chest compressions
• There is NO harm to starting CPR
• Chest compressions should be initiated
immediately, BEFORE opening airway and
providing rescue breathing (CAB rather than
ABC)
• Provide 2 breaths AFTER first 30 chest
compressions
• Immediately resume chest compressions – no
longer than 10 second delay between cycles
CONTRAST MEDIA IN PREGNANT
AND BREAST-FEEDING WOMEN
Case 8
• A 35 yo female needs a CT scan to rule out
cerebral venous sinus thrombosis. She is very
concerned about the effects of the contrast on
the baby. What do you tell her?
Contrast in pregnancy
• Effects of iodinated contrast and gadolinium
are incompletely understood
• Both agents will cross the blood-placental
barrier and enter the fetus
Iodinated contrast
• No known teratogenic or mutagenic effects
• Thyroid function: overall amount of excess
iodide in fetal circulation is likely small
• No known documented cases of neonatal
hypothyroidism from maternal IV contrast
• Neonatal TSH measurement is recommended;
since this is already routinely performed, no
extra steps are needed
Iodinated contrast
• No other adverse effects have been reported,
but evidence is limited
• There is not enough evidence to suggest that
iodinated contrast is safe for the fetus
Recommendations
• Ensure that the study is indicated and that
contrast is indicated
• Ensure that the study will affect the care of
the patient and/or fetus and can not wait until
after patient is no longer pregnant
• Patient should be informed about the
potential risks and benefits, alternative
diagnostic options, and consent should be
documented
Gadolinium
• No known teratogenic or mutagenic effects
• Theoretical potential risk for development of
NSF, although no cases have been reported
Gadolinium recommendations
• Generally recommended that gadolinium
should not be used in pregnant patients
• Risks are unknown and gadolinium should
only be used with great caution
Case 10
• A 27 yo female who is breastfeeding needs a
CT scan (or MRI scan). She wants to know
whether it is safe to continue breast feeding
after the study. What do you tell her?
Iodinated contrast in women who are
breast-feeding
• Nearly 100% of iodinated contrast is cleared
from the bloodstream by 24 hours in patients
with normal renal function
• Less than 1% of IV contrast is excreted into
breast milk
• Less than 1% of contrast ingested by infant is
absorbed by the GI tract
• Therefore, less than 0.01% of injected IV
contrast is absorbed by infant from breast milk
Current recommendations
• It is safe for mother and infant to continue
breast feeding
• If mother remains concerned, she may express
and discard breast milk for up to 24 hours
• No value to stop breast feeding beyond 24
hours
Gadolinium in women who are breastfeeding
• Nearly completely cleared by 24 hours in
patients with normal renal function
• Less than 0.04% is excreted into breast milk
• Less than 1% is absorbed by infant GI tract
• Infant systemic dose is less than 0.0004% of
maternal dose
Current recommendations
• Exactly the same as for iodinated contrast
• It is safe for mother and infant to continue
breast feeding
• If mother remains concerned, she may express
and discard breast milk for up to 24 hours
• No value to stop breast feeding beyond 24
hours
Post-Quiz
1. A patient experiences an acute adverse
contrast reaction. Symptoms include facial
swelling and stridor. What is the first medication
that should be administered?
a. Benadryl
b. Epinephrine
c. Corticosteroid
d. Atropine
Post-Quiz
2. The correct dose/route/concentration of
epinephrine that should be administered in the
setting of an acute allergic contrast reaction is:
a. 1 mg, IV, 1:10,000
b. 0.3 mg, IV, 1:1,000
c. 0.3 mg, IM, 1:1,000
d. 1 mg, IM, 1:10,000
Post-Quiz
3. A patient experiences an acute adverse
reaction during a CT scan. Symptoms include
diaphoresis, hypotension and bradycardia. What
medication should be administered?
a. Benadryl
b. Epinephrine
c. Corticosteroid
d. Atropine
Post-Quiz
4. A patient in the Radiology department
suddenly becomes pulseless and unresponsive.
You initiate CPR. What is the appropriate rate of
compressions:breaths?
a. 15:2
b. 15:1
c. 30:2
d. 100:2
Post-Quiz
5. According to the 2010 American Heart
Association Basic Life Support guidelines, what is
the first step when encountering an
unresponsive person?
a. Open airway
b. Provide rescue breaths
c. Perform chest compressions
d. Activate emergency response system
Post-Quiz
6. According to the 2010 American Heart
Association Basic Life Support guidelines, what is
the second step when encountering an
unresponsive person?
a. Open airway
b. Provide rescue breaths
c. Perform chest compressions
d. Activate emergency response system
References
•
•
•
•
•
•
•
ACR Committee on Drugs and Contrast Media. ACR Manual on Contrast Media Version 9.
2013. Accessed at http://www.acr.org/Quality-Safety/Resources/Contrast-Manual on August
26, 2013.
Berg RA, Hemphill R, Abella BS, Aufderheide TP, Cave DM, Hazinski MF, Lerner EB, Rea TD,
Sayre MR, Swor RA. Part 5: Adult basic life support: 2010 American Heart Association
Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care.
Circulation. 2010;122(suppl 3):S685–S705.
Bush WH and Segal AJ. Recognition and treatment of acute contrast reactions. Applied
Radiology 2009;38:16-21.
Choo KJL, Simons E, Sheikh A. Glucocorticoids for the treatment of anaphylaxis: Cochrane
systematic review. Allergy 2010;65:1205–1211
Lightfoot CB et al. Survey of radiologists’ knowledge regarding the management of severe
contrast material–induced allergic reactions. Radiology 2009;251:691-696
Sheikh A, Shehata YA, Brown SGA, Simons FER. Adrenaline for the treatment of anaphylaxis:
cochrane systematic review. Allergy 2009;64:204–212.
Sheikh A et al. H1-antihistamines for the treatment of anaphylaxis: Cochrane systematic
review. Allergy 2007;62:830–837.