Caudal Epidural Procedure Protocol
Aseptic Technique Requirements
All caudal epidural procedures must be performed using full sterile technique including hand washing, sterile gloves, caps, masks, sterile preparation with chlorhexidine-alcohol solution, and sterile occlusive dressings at the insertion site. 1
- Remove all jewelry before the procedure 1
- Perform thorough hand washing 1
- Wear surgical cap and mask 1
- Use sterile gloves throughout the procedure 1
- Prepare skin with chlorhexidine-alcohol antiseptic solution 1
- Apply sterile draping of the patient 1
Image Guidance Mandate
Fluoroscopic guidance is mandatory for all caudal epidural injections to ensure accurate needle placement and minimize complications including intravascular injection. 2, 3, 4, 5
- Blind caudal injections result in inaccurate needle placement in a substantial number of patients 6
- Ultrasound can be used as an alternative screening tool with 95.8% success rate for identifying the sacral hiatus and confirming correct needle placement 5
- Real-time visualization prevents intravascular injections and other complications 6
Anatomical Landmarks and Needle Placement
Identify the sacral hiatus by palpating bilateral sacral cornua, which are typically 18.0 ± 2.8 mm apart, with the hiatus measuring 4.7 ± 1.7 mm in depth. 5
- Position the patient prone 5
- Use fluoroscopy or ultrasound to visualize the sacral hiatus and bilateral cornua 5
- Mark the skin entry point using fluoroscopic or ultrasound guidance 5
- Insert a 21-gauge spinal needle through the sacrococcygeal membrane into the sacral canal 7, 5
- Advance the needle carefully to avoid dural puncture 1
- Confirm needle position with anteroposterior and lateral fluoroscopic views before injection 5
Medication Selection and Dosing
For caudal epidural injections, use 10 mL total volume consisting of local anesthetic (0.25% or 0.5% bupivacaine or 0.5% lidocaine) with or without 40 mg triamcinolone or equivalent steroid. 8, 7, 9
Local Anesthetic Options:
- Bupivacaine 0.25%: Produces incomplete motor block, suitable when muscle relaxation is not required 8
- Bupivacaine 0.5%: Provides motor blockade for caudal block 8
- Lidocaine 0.5%: 9-10 mL mixed with or without steroid 7, 9
Steroid Addition:
- Triamcinolone 40 mg (1 mL) mixed with 9 mL local anesthetic and physiological solution for total 10 mL volume 7
- Steroids provide superior average relief per procedure compared to local anesthetic alone at two-year follow-up 9
Volume Considerations:
- 10 mL total volume is effective and safe for treating lumbar symptoms without side effects 7
- Maximum single dose: up to 225 mg bupivacaine with epinephrine 1:200,000 or 175 mg without epinephrine 8
- Do not exceed 400 mg total daily dose of bupivacaine 8
Injection Technique
Inject incrementally in 3-5 mL aliquots with aspiration between doses to detect intravascular or intrathecal placement. 8
- Aspirate before each injection to check for blood or cerebrospinal fluid 8
- Inject slowly in divided doses of 3-5 mL 8
- Allow sufficient time between doses to detect toxic manifestations 8
- With ultrasound guidance, observe turbulence of medication fluid in the sacral canal using color Doppler to confirm correct placement 5
- Document final needle position and injectate spread pattern 5
Treatment Frequency and Duration
Administer initial series of 4 weekly injections; if partial response occurs, continue monthly injections to maintain benefit. 7
- Initial treatment: 4 weekly injections over 4 weeks 7
- If patient responds but still has pain, monthly injections are needed 7
- Average number of procedures over two years: 5.3-5.5 treatments 9
- Repeat doses may be given up to once every three hours if needed 8
- Change treatment approach if no response after 4 caudal injections 7
Patient Selection Criteria
Only perform caudal epidural injections in patients with radicular pain radiating below the knee, MRI-confirmed nerve root compression or disc herniation, and failure of at least 4 weeks of conservative treatment. 2, 3, 4
Indications (Level I-II Evidence):
- Lumbar disc herniation with radiculitis 10, 9
- Discogenic pain without disc herniation but with radiculopathy 10
- Post-lumbar laminectomy syndrome 10
- Lumbar spinal stenosis with neurogenic claudication 7, 10
Contraindications:
- Non-radicular low back pain (pain not radiating below the knee) 2, 3
- Known epidural abscess 1
- Active systemic infection 1
- Coagulopathy 1
Complications and Risk Mitigation
Counsel patients about potential complications including dural puncture, insertion-site infections, sensorimotor deficits, cauda equina syndrome, discitis, epidural granuloma, and retinal complications before obtaining consent. 1, 2, 4
- Dural puncture risk is minimized by careful needle advancement and fluoroscopic confirmation 1
- Infection risk is reduced through strict aseptic technique 1
- Intravascular injection is prevented by fluoroscopic guidance and aspiration 6
- No major complications were observed in studies using ultrasound or fluoroscopic guidance 7, 5
Post-Procedure Management
Apply sterile occlusive dressing at the catheter insertion site and monitor patient for immediate complications. 1
- Place sterile occlusive dressing immediately after needle removal 1
- Monitor for 15-30 minutes post-procedure for adverse reactions 7
- Assess pain relief at 2-4 weeks and 3 months follow-up 7, 9
- Significant pain relief is defined as ≥50% reduction in pain scores and functional disability 9
Prophylactic Antibiotic Considerations
When performing caudal epidural injection in a known or suspected bacteremic patient, administer preprocedure antibiotic therapy. 1