IV Radiocontrast Reaction

Last updated 20.09.12

 

Definition

-  Reaction to IV contrast imaging

-  CT, MRI

-  Coronary angiogram, GHPS

-  DISIDA

 

Features

-  Incidence: 5-10% pts receiving contrast media

-  Rangs from mild to death from Anaphalactoid reaction

-  Most are mild

-  Not true allergy but direct histamine release

-  Mucosal (Gastrointestinal or genitourinary) contrast agents do not cause anaphalctoid reactions

-  Increased risk of lactic acidosis if on Metformin

 

Associated S/S

-  Mild

-  Warmth

-  Nausea, vomiting

-  Generally short lived

-  Moderate

-  Severe vomiting

-  Urticaria 1% pts

-  Severe

-  Anaphalactoid reaction 0.1%

 

Risk Factors

-  Prev reaction to radioconstrast

-  Recurrence rate 16-60%

-  Atopy

-  Heart disease

-  Renal disease

-  Beta blockers

-  Decreased response to Adrenaline in Anaphalactoid reaction

-  Elderly

-  Shellfish/seafood allergy is NOT a risk factor

-  Reactions to topical iodine cleaners is NOT a risk factor

-  Iodine allergy is misnomer (trace element)

 

Mx

-  Symptomatic

-  Anti-emetics

-  Anaphalactoid reaction: Adrenaline

-  Prophylaxis if prev reaction

-  Prednisolone 50mg PO 13, 7 & 1hrs prior to contrast

-  Diphenhydramine 50mg PO/IV/IM 1hr prior to contrast

 

 

 

References