Contrast Pharmacology
Clinical Context Required
Protocols listed are illustrative. Always follow local departmental guidelines and radiologist instructions.

Premedication (Previous Reaction)

12-Hour Protocol
  • Prednisone 50mg PO: 13h, 7h, and 1h prior.
  • Diphenhydramine 50mg PO: 1h prior.

Clinical Cautions

Metformin

Cesation only required if eGFR < 30 or AKI present. Resume 48h post-contrast if renal function stable.

Interleukin-2

Risk of delayed hypersensitivity (flu-like symptoms, rash) up to 2 weeks post-injection.

Acute Reaction Management
IMMEDIATE ACTION REQUIRED
If anaphylaxis is suspected: STOP injection, Call for Help (MET/Code Blue), and administer Adrenaline IM immediately.

Immediate Response

1

STOP Injection

Discontinue contrast. Preserve IV access with saline.

2

Call for Help

Alert radiologist. Activate Medical Emergency Team (Code Blue) per local protocol.

3

ABCDE Assessment

Airway, Breathing, Circulation, Disability, Exposure.

Drug Protocols

Severe (Anaphylaxis)

Symptoms: Hypotension, hypoxia, laryngeal edema.

Adrenaline 0.5mg IM (1:1000)

Repeat every 5 mins if needed.

Mild / Moderate

Symptoms: Hives (urticaria), nausea.

Antihistamine: Loratadine 10mg PO / FEM 180mg
Extravasation Protocol
1

Stop & Aspirate

Stop pump. Attempt to aspirate fluid/blood from cannula.

2

Remove & Elevate

Remove cannula. Elevate limb above heart level.

3

Compress

Cold compress (Standard). Warm compress (if low osmolar/minor).

Compartment Syndrome Risk

Urgent surgical review required if:

  • Pain: Severe, disproportionate.
  • Parethesia: Numbness/tingling.
  • Pallor: Pale, cool storage.
  • Pulse: Absent distal pulse (Late sign).
Vasovagal Response
Differentiation: Vasovagal = Hypotension + Bradycardia (Low HR).
Anaphylaxis = Hypotension + Tachycardia (High HR).
1

Positioning (Trendelenburg)

Lay supine. Elevate legs to increase venous return.

2

Supportive Care

Oxygen mask. Cool washer to forehead. Reassurance.

3

Atropine (If persistent)

If HR < 40 and symptomatic: Atropine 0.6mg IV (Medical officer only).

Renal & Screening Guidelines
Parameter Details Action
eGFR < 30 Severe Renal Impairment CONSULT
Hydration required.
eGFR 30-45 Moderate Impairment Use lowest dose. Ensure hydration.
Pregnancy Contrast crosses placenta Avoid unless diagnostics critical.
Example Emergency Contacts
Departmental Protocol Required
Emergency numbers vary by institution. Please familiarise yourself with your specific local emergency activation numbers.
Medical Emergency Team

Activate Code Blue / MET

Follow local protocol. State "Medical Emergency", exact location, and modality.

Contrast Reaction Consultant

Contact Radiologist

Notify the Duty Radiologist or Supervising Physician immediately for advice.