What is the best block for manipulation of a Colles (fracture of the distal radius) fracture?

Best Block for Manipulation of Colles Fracture

Hematoma block is the best anesthetic technique for manipulation of Colles fractures, offering superior pain control during reduction compared to intravenous sedation while maintaining comparable safety profiles.

Comparison of Anesthetic Techniques

Hematoma Block

• Involves direct injection of local anesthetic (typically 10-20 ml of 1.5-2% lidocaine) into the fracture hematoma
• Advantages:
  • Significantly lower pain scores during reduction (median 1.8) compared to IV sedation (median 8.7) 1
  • Shorter time to reduction (0.90 ± 0.47 hours vs 2.63 ± 0.96 hours with IV anesthesia) 2
  • Can be performed in the emergency department without anesthesiology support
  • Avoids risks associated with general anesthesia or deep sedation
  • Comparable safety profile to other techniques 1, 2

Bier's Block (Intravenous Regional Anesthesia)

• Research shows Bier's block may be superior to hematoma block in some aspects:
  • Less painful to administer (median pain score 2.8 vs 5.3 for hematoma block) 3
  • Less painful during manipulation (median pain score 1.5 vs 3.0) 3
  • Better initial radiological outcomes in terms of dorsal angulation 3
  • Lower remanipulation rates (4/72 vs 17/70) 3

Intravenous Sedation

• Less effective for pain control during reduction compared to hematoma block 1
• Requires more monitoring and recovery time
• May require anesthesiology support depending on institutional protocols

Cubital Nerve Block

• Less effective than hematoma block for pain control during reduction
• Complete motor block achieved in only one patient in a comparative study 4

Technique for Hematoma Block

1. Preparation:

   • Test for lidocaine sensitivity
   • Use aseptic technique
   • Prepare 10-20 ml of 1.5-2% lidocaine

2. Administration:

   • Identify fracture site via palpation or with radiographic guidance
   • Insert needle into the fracture hematoma from the dorsal aspect
   • Aspirate to confirm placement (blood return)
   • Inject local anesthetic slowly
   • Wait 5 minutes before attempting reduction 1

3. Potential enhancement:

   • Consider alkalinization of lidocaine (though evidence shows only a trend toward decreased pain on administration) 3

Reduction Technique Considerations

• No significant difference in outcomes between manual manipulation and finger-trap traction techniques 5
• Both techniques achieve approximately 87% satisfactory initial reductions 5
• Be aware that substantial redisplacement often occurs during cast immobilization regardless of reduction technique 5

Pitfalls and Caveats

1. Redisplacement risk:

   • High rates of redisplacement during cast immobilization (only 27-32% maintain acceptable alignment at 5 weeks) 5
   • Consider close radiographic follow-up at 10-14 days

2. Technique limitations:

   • Incomplete anesthesia may occur with hematoma block
   • Consider supplemental analgesia if needed

3. Safety considerations:

   • Monitor for systemic toxicity from local anesthetic, though this is rare with proper technique
   • Highest reported plasma concentrations remain well below toxic levels (0.77 μg/ml) 4

4. Patient selection:

   • Hematoma block may be less effective in highly comminuted fractures where hematoma is disrupted
   • Consider alternative techniques in patients with contraindications to local anesthetics

While Bier's block shows some advantages in research, hematoma block remains the most practical and efficient option in most emergency department settings, offering excellent pain control with minimal resource requirements and comparable safety.