2  Contrast Reaction

2.1 Acute Reaction

2.1.1 Sign & Symptoms

	Allergic-like	Physiologic
Mild	Limited urticaria / pruritis Cutaneous Edema Limited “itchy”/“scratchy” throat Nasal congestion Sneezing / conjunctivitis / rhinorrhea	Limited N/V Transient flushing / warmth / chills Headache / dizziness / anxiety / altered taste Mild hypertension Vasovagal reaction (resolves spontaneously)
Moderate	Diffuse urticaria / pruritis Diffuse erythema (V/S stable) Facial edema (w/o dyspnea) Wheezing / bronchospasm (mild/no hypoxia) Throat tightness or hoarseness (w/o dyspnea)	Protracted N/V Hypertensive urgency Isolated chest pain Vasovagal reaction (response to Tx)
Severe	Diffuse edema / facial edema + dyspnea Diffuse erythema + hypotension Laryngeal edema + (stridor and/or hypoxia) Wheezing / bronchospasm (significant hypoxia) Anaphylactic shock (hypotension + tachycardia)	Arrhythmia Hypertensive emergency Convulsions, seizures Vasovagal reaction (resistant to Tx)
Adapted from Table 1 of ACR Manual On Contrast Media (2022)

2.1.2 Treatment

	Treatment	Disposition
N/V	Stop exam Sit to avoid aspiration	Observe 30 min
Urticaria	Usually self-limited Moderate: CPM 4 mg PO q 6-8 hr Severe: CPM 10 - 20 mg IV	Possible admission
Facial or laryngeal edema	O2 mask 6 - 10 LPM Epinephrine SC or IM (1:1000) 0.1-0.3 mL (= 0.1 - 0.3 mg) (maximum 1 mg) If Hypotension, Epinephrine (1:10,000) slow IV 1-3 mL (= 0.1 - 0.3 mg)	Possible admission
Bronchospasm	O2 mask 6 - 10 LPM B2 agonist: e.g., Ventolin 2-3 puffs If not response, epinephrine SC or IM If O2 sat < 88% or Severe, ask for help	Possible admission
Hypotension + HR > 100	Monitor: ECG, pulse oximeter, BP O2 mask 6 - 10 LPM Lift leg 60 deg / Trendelenburg IV fluid (NSS or RLS) large volume If not response, Epinephrine slow IV	Possible admission
Hypotension + HR < 60 (vagal reaction)	Monitor: ECG, pulse oximeter, BP O2 mask 6 - 10 LPM Lift leg 60 deg / Trendelenburg IV fluid (NSS or RLS) large volume If not response, Atropine 0.6-1 mg slow IV (maximum 2-3 mg)	Possible admission
Severe Hypertension	Monitor: ECG, pulse oximeter, BP O2 mask 6 - 10 LPM Nitroglycerine 0.4 mg tab SL (maximum 3 doses) If not response, Labetalol 20 mg IV then 20-80 mg IV q 10 min (max 300 mg)	Admission
Seizures	Monitor: V/S (due to resp. depression effect of drug) O2 mask 6 - 10 LPM Diazepam 5 mg IV or Midazolam 0.5-1 mg IV	Possible admission
Pulmonary edema	O2 mask 6 - 10 LPM Lift head up Furosemide 20-40 mg IV slow push Morphine 1-3 mg IV	Possible admission
Adapted from Table 3 of ACR Manual On Contrast Media (2022)