What are the cumulative fluoroscopic on-time benchmarks for lumbar epidural injections?

Fluoroscopic On-Time Benchmarks for Lumbar Epidural Injections

The average fluoroscopic on-time for lumbar epidural injections ranges from 36-47 seconds per injection site, with transforaminal approaches requiring approximately 37 seconds and interlaminar approaches requiring approximately 47 seconds per level. 1

Fluoroscopic On-Time by Approach Type

Different approaches to lumbar epidural injections have varying fluoroscopic requirements:

Transforaminal Approach

• Average fluoroscopy time: 37.3 seconds 1
• Radiation dose per procedure: 0.123 mGy·m² 1
• Alternative measurement: 11-161 seconds (mean 36.0 seconds, median 29 seconds) 2

Lumbar Interlaminar Approach

• Average fluoroscopy time: 46.7 seconds (longest among epidural approaches) 1
• Radiation dose per procedure: 0.191 mGy·m² 1

Caudal Approach

• Average fluoroscopy time: 18.2 seconds (mean), 13 seconds (median) 2
• Radiation dose per procedure: 0.218 mGy·m² (highest among epidural approaches) 1

Factors Affecting Fluoroscopic Time and Radiation Exposure

Several factors influence the fluoroscopic time required for lumbar epidural injections:

1. Physician experience: Less experienced operators typically require longer fluoroscopy times 1
2. Patient BMI: Higher BMI correlates with increased radiation exposure 1
3. Anatomical complexity: Previous surgery, scoliosis, and other anatomical variations can increase fluoroscopy time 1
4. Approach selection: Transforaminal approaches require longer fluoroscopy time than caudal approaches but may deliver less radiation per unit time 2

Radiation Dose Considerations

When performing lumbar epidural injections, it's important to consider both fluoroscopy time and total radiation exposure:

• Conventional fluoroscopy for lumbar ESI delivers an effective dose of approximately 0.85 mSv 3
• CT fluoroscopy without planning scan delivers approximately 0.45 mSv 3
• Ultralow-dose CT-fluoroscopy can deliver even lower effective doses (0.15 mSv) compared to conventional fluoroscopy (0.30 mSv) 4

Best Practices for Minimizing Radiation Exposure

To minimize radiation exposure while maintaining procedural efficacy:

1. Use pulsed fluoroscopy: Reduces radiation exposure compared to continuous fluoroscopy 5
2. Optimize dose per frame: Use the lowest dose per frame that provides adequate visualization 5
3. Select appropriate frame rate: 10-15 frames/second is generally adequate for interventional procedures 5
4. Limit total fluoroscopy time: Be conscious of cumulative exposure time
5. Consider ultralow-dose CT-fluoroscopy: May provide lower radiation exposure than conventional fluoroscopy for some patients 4

Clinical Implications

While minimizing radiation exposure is important, the primary goal remains effective pain management:

• Fluoroscopy guidance is considered the gold standard for targeted epidural injections 5
• Image guidance is essential for safety and efficacy in epidural injections 5
• The benefits of properly performed image-guided injections generally outweigh the radiation risks when following best practices

By being aware of these benchmarks and following radiation reduction strategies, clinicians can optimize the balance between diagnostic quality and radiation exposure during lumbar epidural injections.