Contrast Reaction Management (ACR 2024)

Algorithm Steps

1. ▶

   Start

   Contrast Reaction Suspected

   During or after contrast administration

   1. ⚠

      Warning

      STOP Contrast Injection

      Immediate action

      • Stop contrast administration immediately
      • Keep IV access
      • Call for help
      • Have crash cart ready
      • Notify radiologist
      1. ◆

         Decision

         Severity Assessment

         Classify reaction severity

         1. ●

            Action

            Mild Reaction

            Self-limited, usually no treatment needed

            • SYMPTOMS:
            • - Limited urticaria/hives
            • - Mild itching
            • - Nasal congestion
            • - Sneezing
            • - Nausea (no vomiting)
            • - Flushing/warmth
            • TREATMENT:
            • - Observation (30 min minimum)
            • - Diphenhydramine 25-50mg PO/IV (optional)
            • - Reassurance
            1. ●

               Action

               Post-Reaction Observation

               Monitor for biphasic reaction

               • MILD: 30 minutes observation
               • MODERATE: 1-2 hours observation
               • SEVERE: Extended observation/admission
               • BIPHASIC REACTION:
               • - Can occur 1-72 hours later
               • - Occurs in up to 20% of anaphylaxis
               • - Educate patient on symptoms
               1. ●

                  Action

                  Documentation & Prevention

                  Critical for future care

                  • DOCUMENT IN CHART:
                  • - Exact symptoms and timing
                  • - Contrast type and volume
                  • - Treatment given and response
                  • - Severity classification
                  • ALLERGY ALERT:
                  • - Add to allergy list
                  • - Specify: 'Iodinated contrast'
                  • - Note severity
                  • FUTURE STUDIES:
                  • - Consider alternative modality
                  • - If contrast needed: Premedication
                  1. ●

                     Action

                     Premedication Protocol

                     For high-risk patients needing contrast

                     • ACR RECOMMENDED REGIMEN:
                     • - Prednisone 50mg PO at 13h, 7h, 1h before
                     • - Diphenhydramine 50mg PO/IV 1h before
                     • EMERGENCY PROTOCOL (if urgent):
                     • - Methylprednisolone 40mg IV q4h x 2
                     • - Diphenhydramine 50mg IV 1h before
                     • NOTE:
                     • - Reduces but doesn't eliminate risk
                     • - Breakthrough reactions still possible
                     1. ✓

                        Outcome

                        Outcome

                        Follow-up

                        • Mild: Return to normal activity
                        • Moderate: Usually no sequelae
                        • Severe: Referral to allergist
                        • Fatality rate: Very rare (<1:170,000)
         2. ●

            Action

            Moderate Reaction

            More significant symptoms, treatment needed

            • SYMPTOMS:
            • - Diffuse urticaria
            • - Facial/laryngeal edema (mild)
            • - Bronchospasm (mild wheeze)
            • - Tachycardia
            • - Vomiting
            • TREATMENT:
            • - O2 6-10 L via mask
            • - Diphenhydramine 25-50mg IV
            • - Albuterol nebulizer if wheeze
            • - Monitor closely
            • - Prepare epinephrine
         3. ⚠

            Warning

            Severe Reaction (Anaphylaxis)

            LIFE-THREATENING - ACT IMMEDIATELY

            • SYMPTOMS:
            • - Hypotension (SBP <90)
            • - Respiratory distress/stridor
            • - Laryngeal edema (severe)
            • - Severe bronchospasm
            • - Altered consciousness
            • - Cardiac arrest
            • THIS IS ANAPHYLAXIS
            1. ⚠

               Warning

               Anaphylaxis Treatment

               EPINEPHRINE IS FIRST-LINE

               • EPINEPHRINE (CRITICAL):
               • - Adult: 0.3-0.5 mg (0.3-0.5 mL of 1:1000) IM
               • - Anterolateral thigh preferred
               • - Repeat q5-15 min if needed
               • ADJUNCTS:
               • - IV access, fluids (NS 1-2L bolus)
               • - O2 high flow
               • - Diphenhydramine 50mg IV
               • - Methylprednisolone 125mg IV
               • - Albuterol for bronchospasm
               • IF REFRACTORY:
               • - Epinephrine drip
               • - Call code/anesthesia
         4. ●

            Action

            Vasovagal Reaction

            Not allergic - different treatment

            • SYMPTOMS:
            • - Bradycardia (not tachycardia)
            • - Hypotension
            • - Diaphoresis
            • - Pallor
            • - Nausea
            • TREATMENT:
            • - Elevate legs (Trendelenburg)
            • - IV fluids
            • - Atropine 0.5-1 mg IV if bradycardia severe
            • - Usually resolves quickly