Safety

Contrast & Safety

A practical contrast safety desk reference. Use this as a workflow reminder and follow your department policy for final decisions and emergency drug doses.

IodinatedBefore iodinated contrastBefore any contrast-enhanced CT, CTA or fluoroscopic procedure.›

Key points

  • Confirm indication and expected diagnostic benefit.
  • Ask about previous contrast reaction and severity.
  • Check renal function when required by local policy.
  • Review pregnancy status when relevant.
  • Confirm IV access quality and injection rate.

Action

  • Use the lowest dose that answers the clinical question.
  • Document allergy/reaction history clearly.
  • Escalate to radiologist when prior severe reaction or high renal risk exists.

Warning

Do not delay emergency life-saving imaging solely for routine screening if the result will change urgent management.

GadoliniumBefore gadolinium contrastBefore contrast-enhanced MRI.›

Key points

  • Confirm that contrast is needed for the question.
  • Check renal function in at-risk patients.
  • Use local GBCA group policy for renal impairment.
  • Ask about prior GBCA reaction.
  • Review pregnancy status when relevant.

Action

  • Prefer macrocyclic/group II agents when local policy requires lower NSF risk.
  • Document agent and dose.
  • Use non-contrast MRI when it answers the question.

Warning

Avoid routine gadolinium in pregnancy unless expected benefit clearly outweighs risk.

ReactionsMild contrast reactionLimited urticaria, itching, mild nausea, warmth or self-limited symptoms.›

Key points

  • Differentiate allergy-like from physiologic symptoms.
  • Observe until symptoms improve.
  • Record reaction type, severity and treatment.
  • Warn the patient to report worsening symptoms.

Action

  • Stop injection if symptoms occur during injection.
  • Assess airway, breathing and circulation.
  • Call radiologist/nurse per local protocol.
  • Treat according to local emergency chart.

Warning

Mild symptoms can rarely progress, so do not leave the patient unattended until stable.

ReactionsModerate or severe reactionBronchospasm, facial/laryngeal edema, hypotension, severe vomiting, collapse or anaphylaxis concern.›

Key points

  • This is an emergency workflow.
  • Airway and hemodynamics come first.
  • Adrenaline/epinephrine use follows local emergency protocol.
  • Document timing, contrast type, dose and treatment.

Action

  • Stop contrast injection immediately.
  • Call emergency response.
  • Give oxygen and monitor vitals.
  • Prepare emergency medication according to site protocol.
  • Transfer for continued observation when needed.

Warning

Use the department's official emergency drug chart. Do not rely on memory for doses.

ReactionsPrior contrast reactionPatient reports previous iodinated or gadolinium reaction.›

Key points

  • Identify exact agent if possible.
  • Classify reaction as mild, moderate or severe.
  • Separate true allergy-like reaction from nausea/warmth/vasovagal symptoms.
  • Previous severe reaction needs radiologist review.

Action

  • Consider alternative modality or non-contrast protocol.
  • Use different agent when appropriate.
  • Premedication follows local policy, not automatic habit.
  • Ensure emergency readiness.

Warning

Premedication reduces risk but does not guarantee prevention of a breakthrough reaction.

RenalReduced eGFR and iodinated contrastCT contrast request in patient with known or suspected renal impairment.›

Key points

  • Assess urgency and diagnostic benefit.
  • Look for acute kidney injury, not just chronic eGFR.
  • Hydration strategy follows local policy.
  • Avoid duplicate nephrotoxic exposures when possible.

Action

  • Discuss high-risk cases with radiologist/referrer.
  • Use alternative imaging if it answers the question.
  • Document risk-benefit decision for urgent studies.

Warning

Do not use a single fixed eGFR threshold without considering urgency, AKI and local policy.

RenalReduced eGFR and gadoliniumMRI contrast request in renal impairment or dialysis patient.›

Key points

  • NSF risk depends on agent group and renal status.
  • Use local GBCA policy and approved agents.
  • Avoid unnecessary repeat GBCA exposure.
  • Dialysis timing decisions follow local policy.

Action

  • Confirm contrast necessity.
  • Use safer agent category per local protocol.
  • Document agent and renal status.

Warning

High-risk renal patients should be reviewed before GBCA administration.

RenalMetformin and iodinated contrastPatient on metformin undergoing iodinated contrast study.›

Key points

  • Risk relates to renal function and acute kidney injury.
  • Routine stopping is not always required in low-risk patients.
  • Policies vary by institution.
  • Clear instructions reduce patient confusion.

Action

  • Follow local metformin/eGFR policy.
  • Give written restart advice when metformin is held.
  • Escalate if AKI or severe renal impairment is present.

Warning

Do not give generic advice without checking the department policy.

PregnancyPregnancy and CT contrastPregnant patient needs CT/CTA with iodinated contrast.›

Key points

  • Justification and optimization are essential.
  • Iodinated contrast crosses placenta.
  • Urgent maternal diagnosis may justify contrast.
  • Dose optimization matters for ionizing imaging.

Action

  • Prefer US/MRI if diagnostic and timely.
  • Do not delay urgent maternal care.
  • Document risk-benefit discussion when appropriate.

Warning

Maternal stabilization and accurate diagnosis often protect both mother and fetus.

PregnancyPregnancy and MRI gadoliniumPregnant patient has MRI request where contrast is considered.›

Key points

  • Non-contrast MRI is preferred when sufficient.
  • Gadolinium crosses placenta.
  • Use only when essential and expected benefit is high.
  • Radiologist review is required.

Action

  • Remove contrast if non-contrast MRI can answer the question.
  • Discuss with referring clinician for high-impact cases.
  • Document rationale when GBCA is used.

Warning

Avoid routine gadolinium during pregnancy.

PregnancyBreastfeeding after contrastBreastfeeding patient asks about iodinated contrast or gadolinium.›

Key points

  • Very small amounts enter breast milk.
  • Even smaller amounts are absorbed by the infant gut.
  • Many guidelines allow continued breastfeeding.
  • Patient preference should be respected.

Action

  • Provide calm counseling.
  • Offer pump-and-discard only if patient strongly prefers after explanation.
  • Document discussion if there is concern.

Warning

Avoid unnecessarily alarming language.

ProcedureContrast extravasationPain, swelling or failed injection during CT/MRI contrast administration.›

Key points

  • Stop injection immediately.
  • Assess volume, site, pain, skin changes and neurovascular status.
  • Most cases are managed conservatively.
  • Severe pain, blistering or neurovascular compromise needs urgent review.

Action

  • Elevate limb.
  • Apply local hot/cold policy.
  • Give written return advice.
  • Document agent, volume and examination.

Warning

Do not ignore progressive pain, numbness, reduced perfusion or skin blistering.

PediatricPediatric contrast safetyChild undergoing CT, MRI or fluoroscopic contrast exam.›

Key points

  • Weight-based dose is mandatory.
  • Use child-appropriate IV access and injection rate.
  • Minimize radiation where applicable.
  • Child-friendly preparation reduces motion and failed studies.

Action

  • Confirm weight and dose.
  • Use pediatric protocol.
  • Prepare reaction equipment and monitoring appropriate for age.

Warning

Never estimate pediatric contrast dose without a current weight.

ProcedureContrast checklist for high-risk scanPatient has multiple risks: renal impairment, prior reaction, pregnancy, severe illness or poor IV access.›

Key points

  • Clarify the clinical question.
  • Check if non-contrast or alternate modality can answer it.
  • Assess risk factors separately instead of using one generic label.
  • Make a documented plan before injection.

Action

  • Discuss with radiologist.
  • Confirm emergency readiness.
  • Use appropriate agent and route.
  • Record final decision and limitation.

Warning

High-risk does not always mean no contrast; it means deliberate risk-benefit planning.