Transcript MR scanning and cont.. - University of Washington

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.
2.
3.
4.
I.V. access
Airway / suction / oxygen
Cardiac monitor / pulse oximeter
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.
b.
c.
d.
Rapidity of breathing
Systolic blood pressure
Diastolic blood pressure
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.
b.
c.
d.
Atropine
Benadryl®
Beta-agonist inhaler
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.
2.
3.
4.
5.
6.
•
Airway / suction / oxygen
Obtain pulse; I.V. access
Leg elevation
Provide medications
Cardiac monitor / pulse oximeter
Obtain Blood pressure
Take “ownership” of a task
Calm, Unresponsive
• Hypotension
• Hypoglycemia
HYPOTENSION
• With Tachycardia
• With Bradycardia
HYPOTENSION WITH
TACHYCARDIA
Treatment includes:
•
Leg elevation (approx. 60°)
•
Oxygen by mask ( 6-10 L/min )
•
IV fluids (normal saline or Ringer’s lactate)
HYPOTENSION WITH
BRADYCARDIA
Treatment includes:
• Leg elevation (approx. 60°)
• Oxygen by mask ( 6-10 L/min )
• IV fluids ( normal saline or Ringer’s solution)
• Atropine IV
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
 With significant Hypotension – Use IV
• If hypotension is not significant –
can use I.M. or subcutaneous route
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.
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
( * if not hypotensive )
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
BENADRYL
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.
2.
3.
4.
5.
6.
•
Airway / suction / oxygen
Obtain pulse; I.V. access
Leg elevation
Provide medications
Cardiac monitor / pulse oximeter
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.
2.
3.
4.
I.V. access
Airway / suction / oxygen
Cardiac monitor / pulse oximeter
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 and
bradycardia is: (a, b, or c)
a. IV fluids and atropine
b. IV fluids and epinephrine
c. Nitroglycerine
Answer to Question # 7
The key finding for diagnosing a vagal
reaction is: (a, b, c, or d)
a.
b.
c.
d.
Rapidity of breathing
Systolic blood pressure
Diastolic blood pressure
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.
b.
c.
d.
Atropine
Benadryl®
Beta-agonist inhaler
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