Intravenous contrast media: Management and prevention of adverse reactions

1. Intravenous contrast media:Management and prevention of adverse reactions Zulmarie Roig, MD NSMC Department of Radiology

2. Goals • Review some of the commonly used contrast agents for CT and MRI • Study the different types of adverse reactions • Discuss how to manage and treat an adverse reaction • Review pretreatment protocol, for patients with known previous contrast reaction/allergy

3. Intravenous contrast • Enhance and improve the visibility of internal organs/body structures • Improve the imaging quality • CT • Clear iodine compound • Ionic • Non-ionic • Bound to organic compound • Fewer side effects: do not dissociate into component molecules

4. Intravenous contrast • Ionic • Higher osmolality • More side effects • Examples: • Hypaque 50 (osmolality 1550) • Isopaque 370 (2100)

5. Intravenous contrast • Nonionic • Lower osmolality • Less side effects • Toxicity decreases as osmolality approaches the osmolality of serum • Examples: • Isovue 370 • Omnipaque 350 • Ultravist 370 • Visipaque 320

6. Intravenous contrast

7. Intravenous contrast • MRI • Classified by chemical composition, magnetic properties, and biodistribution • Gadolinium based : paramagnetic • Iron oxide: superparamagnetic • Iron platinum: superparamagnetic • Manganese: paramagnetic

8. Intravenous contrast • MRI • Gadolinium (Gd): Paramagnetic • Most commonly used • Chelated form- bind to an organic compound • low as 0.1 mmol per kg body mass • Extracellular fluid agents • Ionic (Magnevist) • Neutral (Gadavist) • Blood pool agents • Albumin-binding (Ablavar) • Organ specific agent • Primovist, Multihance- hepatobiliary agents

9. Contrast adverse reactions • Mechanism • Direct release of histamine • Contrast molecule causes an effect on antigen binding sites on IgE of mast cells (4%) • Severity of reaction-quantity of circulating IgE and mast cells • Or due to direct contact with blood vessel endothelium , leads to activation of factor XII -> kallikrein ->bradykinin -> prostaglandins -> leucotrines (histamine like effect)

10. Contrast adverse reactions • Mild • Self limited • Moderate • Require treatment • Not immediate life threatening • Severe • Life threatening

11. Contrast adverse reactions • Mild • Nausea/vomiting • Cough • Warmth • HA • Dizziness • Altered taste • Itching • Chills, sweats • Rash, hives • Nasal stuffiness • Swelling face/eyes

12. Contrast adverse reactions • Moderate • Tachycardia / bradycardia • Hypertension • Hypotension • Pronounce cutaneous reaction • Dyspnea • Wheezing/ bronchospasm • Laryngeal edema

13. Contrast adverse reactions • Severe • Severe/progressive laryngeal edema • Arrhythmia • Profound hypotension • Seizures • Cardiac arrest • Anaphylaxis • Occurs soon after injection

14. Contrast adverse reactions • Incidence of allergic reaction to CT contrast: • Mild : 0.7 - 3% • Moderate • 1 in 250 pt (0.4%) • Severe, life threatening • Uncommon • 1 in 2500 (0.04%) • MRI contrast: • 0.07-2.4%

15. Contrast adverse reactions • Delayed reaction • Occur 3 hr to 7 days • Incidence: 0.5 – 9% • Higher rate; nonionic low osmolar agents • Cutaneous reactions , most common • Nausea/vomiting, HA

16. Management and treatment of reactions • Call for assistance • Evaluate patient: Look and talk to the patient • Vital signs • Quickly evaluate • ? hives, edema, SOB, coughing, wheezing, inspiratory stridor

17. Treatment • Mild and moderate reactions • Mild • Support • Medication • Diphenhydramine (Benadryl ) 25-50 mg PO or IV • Moderate • O2 • IV fluids • Hx of asthma or bronchospasm- albuterol inhaler • Benadryl 25 mg IV • corticosteroids

18. Treatment • Severe reactions • If anaphylaxis • Stop contrast injection, saline • Secure airway • Restore BP • IV fluids • Laying patient flat, raising feet

19. Treatment • Severe reactions • O2 • Antihistamine (Benadryl 25 mg IV, chlorpheniramine 10-20 mg IV) • Corticosteroid (hydrocortisone 100-300 mg IV) • EpiPen

20. Medications • Epinephrine • IV: 0.5 to 1 ml (50 to 100 mcg) of the 10 cc bristojet 1:10,000 concentration • Do not use the 1:1000 strength IV • SQ: 0.3 ml (300 mcg) of the 1:1000 concentration (1ml vial)

21. Medications • Albuterol inhaler • Atropine – treat bradycardia • 0.6-1 mg IV • Diphenhydramine • 25-50 mg IV or IM • Clonidine- hypertensive crisis • 200 mcg (0.2 mg) PO

22. Pre-medication • Indicated in patients with prior allergy / reaction • Does not eliminate risk for breakthrough reaction • Breakthrough reaction – 10 % premed patients • Breakthrough reaction: reaction that occurs after IV contrast in patient’s premedicated with corticosteroids.

23. Pre-medication • Risk factors: • Severe allergy to any substance • Allergy to 4 or > allergens • Drug allergy • Chronic use of corticosteroids • Change contrast media, another low osmolar agent • Schedule studies at hospital (not out patient centers)

24. Pre-medication • Severity signs, and symptoms = index reaction • Mild index of reaction – low risk of developing a severe breakthrough reaction • Pre-medicated patients + low osmolar agents: • 88 % pt with prior mild reactions do not repeat breakthrough • Moderate /severe index: • High risk for a second moderate or severe reaction (42%). • Risk of an adverse reaction to MRI contrast: 8 times higher if prior reaction

25. Pre-medication • Oral regimen: • Prednisone 50 mg PO, 13, 7, and 1 hour prior to exam/ or Methylprednisolone Sodium Succinate (Solu-Medrol) 32 mg PO 12, and 2 hr prior • Diphenhydramine (Benadryl) 50 mg PO 1 hour prior to study • IV regimen: • Hydrocortisone 200 mg IV 13,7, and 1 hr before procedure • Benadryl 50 mg IM or IV, I hr before • Urgent IV protocol: • Hydrocortisone 200 mg 4 , 1 hr prior / or Solu-Medrol 120 mg 1 hr before • Benadryl 50 mg IM or IV , 1 hr prior

26. References • ACR Manual of Contrast Media, Version 8, 2012 • Recognition and treatment of acute contrast reactions, Applied Radiology Vol 38, #12, 12/2009. • Frequently Asked Questions: Iodinated Contrast Agents, Radiographics, 2004; 24:S3-S10 • Repeat contrast Medium Reactions in Premedicated patients, Radiology: Vol 253:Number 2, 2009 • Delayed Adverse Reaction to Contrast enhanced CT, Radiology: Vol. 255: Num 3-June 2010.