Anaphylactic Shock Following Nonionic Contrast Medium during Caudal Epidural Injection

Area of Science:

• Radiology
• Anesthesiology
• Allergy and Immunology

Background:

• Caudal epidural injections are frequently used for low back pain and sciatica.
• Complications from fluoroscopically guided epidural injections are less common than blind injections.
• Contrast media used in these procedures can cause adverse reactions.

Observation:

• A patient undergoing caudal epidural injection for low back pain experienced immediate anaphylactic shock after iohexol administration.
• The patient had no prior history of allergy to ionic contrast media (ioxitalamate).
• Symptoms included dizziness and a severe drop in systolic blood pressure (60 mmHg), progressing to a drowsy state.

Findings:

• Immediate treatment with subcutaneous epinephrine (0.2 mg) resulted in a blood pressure increase to 90 mmHg within 30 minutes.
• The patient recovered fully without any sequelae.
• This case demonstrates a rare but severe reaction to nonionic intravenous contrast media.

Implications:

• Life-threatening anaphylactic reactions to intravenous contrast media during epidural injections necessitate rapid diagnosis and treatment.
• Healthcare providers should be vigilant for potential contrast media hypersensitivity, even in patients without a prior allergic history.
• This underscores the importance of having emergency protocols and medications readily available during minimally invasive procedures involving contrast agents.