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.