Contrast Reactions

Pretreatment
Reduces minor reactions but probably does not reduce life-threatening reactions
Emergency
hydrocortisone 200 mg IV every 4 hrs until procedure
Benadryl 50 mg IM 1 hr before procedure
Routine
Benadryl 50 mg IM or PO 1 hr before procedure
Prednisone 50 mg PO 13, 7, 1 hr before procedure
Observe patient at least 30 minutes following injection
N-Acetylcysteine 600 or 1,200 mg PO BID the day before and day of the procedure or 150 mg/kg IV over .5 hr or 50 mg/kg IV over 4 hr
General
  • > 10 million diagnostic procedures / year
  • Conventional ionic contrast reactions - 10%
  • 1 in 1000 severe
Contrast Reactions
  • Contrast Myths
    • not caused by iodine
    • not related to shellfish
    • not true allergy (no drug-antibody)
    • mechanism remains unknown
  • Anaphylactoid (idiosyncratic)
    • unpredictable
    • dose independent
    • prevalence 1-2% (0.04 - 0.22% severe)
    • fatal 1 in 75,000
  • Chemotoxic
    • predictable
    • dose dependent
    • due to osmolality or ionic composition
  • Nonionic vs Ionic
    • Contrast reactions decreased 5 fold
    • Fatalities unchanged
Risk factors
  • Previous contrast reaction either moderate or severe
  • asthma
  • allergy history requiring medical treatment
  • pretesting poor predictor of reaction
  • Repeat Reactions, ionic
    • bronchospasm 40% to facial edema 70%
    • decrease to 6 - 9% with pretreatment
    • decrease to 0.6% with pretreatment and switch to nonionic
  • Late Reactions
    • 1 hr to 1 week following contrast injection
    • Headache, myalgias, fever, skin reactions
    • Risk Factorsusually self-limited, treat severe reactions with steroids
      • Previous contrast reaction
      • Interleukin-2 treatment
    • usually self-limited, treat severe reactions with steroids
Severity of reactions

Minor: Nausea & vomiting, Urticaria, Pruritis, Diaphoresis

Moderate:Faintness, Facial edema, Laryngeal edema, Bronchospasm

Severe: Pulmonary edema, Respiratory arrest, Cardiac arrest, Seizures

Renal Toxicity (increased serum creatinine by more than 25% or > 0.5 mg%)

2-7% 
Risk Factors 
5 - 10 fold increase with pre-existing renal insufficiency (increased creatinine) 
Dehydration 
CHF 
Age > 70 
Taking nephrotoxic drugs (nonsteroidal inflammatory agents, gentomycin etc.) 
direct relationship between serum creatinine and likelihood nephrotoxicity 
Hydrate 100 ml/hr Normal saline 4 hrs prior to procedure, continue for 24 hours 
Those on hemodialysis do not need extra seesions or dialysis immediately following contrast administration

Metformin (Glucophage)
oral diabetic agent 
patients with renal insufficiency may develop lactic acidosis 
withhold drug for 48 hrs after contrast administration in all patients taking this drug

Screening Creatinine

Which patients need screening creatinine?
Consider if patient has one of the following risk factors
Known renal insufficiency 
Diabetes mellitus 
Lasix or nephrotoxic drugs 
Solitary kidney

Study: 2034 outpatients, 66 (3.2%) had elevated creatinine (>2.0) One or more risk factors in 64. Two patients (0.1%) with renal insufficiency had no risk factors.

Pregnancy
Discard breast milk for 24 hours following contrast administration
Treatment contrast reactions
Nausea & Vomiting

usually self-limited 
protracted: Prochlorperazine (Compazine) 5-10 mg IM

Urticaria
Diphenhydramine (Benadryl) 25 - 50 mg IM, caution: drowsiness 
add Cimetidine (Tagamet) 300 mg in 20 ml, IV slowly

Hypotension

bradycardia (Vasovagal)
elevate legs (infuses 700 ml) 
IV fluid (normal saline) 
O2 3 L/min 
atropine 0.6 mg IV push, repeat up to 3 mg total

tachycardia
elevate legs 
IV fluid (normal saline) may require > 1 Liter 
O2 3 L/min

Bronchospasm or laryngeal edema
O2 3 L/min 
Epinephrine 1:1000 (0.1 - 0.2 ml subq) or 1:10,000 1 ml IV over 3 min 
B2 agonist 2 -3 puffs 
albuterol (Proventyl) 
metaproterenol (Alupent) 
terbutaline (Brethaine)

Anaphylactoid
O2 3 L/min 
IV normal saline 
Epinephrine 
Benadryl 25 - 50 mg IV 
Tagamet 300 mg in 20 ml IV slowly 
Solumedrol 1 gm IV 
Note: if patient taking beta blocker 
glucagon 1 - 5 mg IV bolus followed by infusion 5-15 ug/min or 
isoproternol 1:5000 (0.2 mg/ml) 
IV 0.5 - 1.0 ml diluted in 10 ml 
1 mg increments

Seizures
protect airway 
Diazepam (valium) 5 mg IV slowly

Suspected pheochromocytoma
phentolamine (Regitine) 5.0 ml (5 mg) IV bolus

Extravasation

Initial
Elevate extremity 
Ice pack 3x day 
Observe for 2-4 hours if volume > 5ml

Surgical Consultation
ionic > 30 ml 
nonionic > 100 ml 
skin blistering 
altered tissue perfusion 
increasing pain after 2-4 hours 
change in sensation distal to site of extravasation

 

References

Thomsen HS. Guidelines for contrast media from the European society of urogenital radiology. AJR 2003; 181:1463-71. [Related Records]

Bush WH, Swanson DP. Acute reactions to intravascular contrast media: types, risk factors, recognition, and specific treatment. AJR 1991; 157:1153-1161. [Related Records]

Tippins RB, Torres WE, Baumgartner BR, Baumgarten DA. Are screening serum creatinine levels necessary prior to outpatient CT examinations? Radiology 2000; 216:481-484. [Related Records]

Katayama H, Yamaguchi K, Kozuka T, et al. Adverse reactions to ionic and nonionic contrast media. A report from the Japanese Committee on the Safety of Contrast Media. Radiology 1990; 175:621-628. [Related Records]

Cohan RH, Ellis JH, Garner WL. Extravasation of radiographic contrast material: recognition, prevention, and treatment. Radiology 1996; 200:593-604. [Related Records]

McClennan BL. Adverse reactions to iodinated contrast media. Recognition and response. Invest Radiol 1994; 29 Suppl 1:S46-50. [Related Records]

Ashley JB,Millward SF. Contrast agent-induced nephropathy: a simple way to identify patients with preexisting renal insufficiency. AJR 2003; 181:451-4. [Related Records]

Bettmann MA. Frequently asked questions: iodinated contrast agents.Radiographics 2004; 24 Suppl 1:S3-10. [Related Records]

Disclaimer: Information provided is not intended to be medical or technical advice. The information given at this site is for educational purposes only and is not sufficient for medical decisions. I disclaim any liability for the acts of any physicians or any other individual who receives any information on any medical procedure through this web site. I accept no legal responsibility for any injury and/or damage to persons or property from any of the suggestions or material discussed herein. Practioners should read pharmaceutical manufacturers' package inserts for instructions about dosages, contraindications, and other drug-related information.