What is the recommended dose of bupivacaine (local anesthetic) for closed reduction of a distal radius fracture?

Bupivacaine Dosing for Closed Reduction of Distal Radius Fracture

For closed reduction of a distal radius fracture, the maximum recommended dose of bupivacaine 0.25% is 1 ml/kg (equivalent to 2.5 mg/kg) for peripheral nerve blocks and wound infiltration. 1

Recommended Dosing by Technique

Hematoma Block/Wound Infiltration

• Use bupivacaine 0.25% at a maximum dose of 1 ml/kg (2.5 mg/kg) 1
• Alternative options include:
  • Levo-bupivacaine 0.25% at a maximum dose of 1 ml/kg (2.5 mg/kg) 1
  • Ropivacaine 0.2% at a maximum dose of 1.5 ml/kg (3 mg/kg) 1

Peripheral Nerve Block (if used)

• For peripheral nerve blocks (such as wrist blocks), use bupivacaine 0.25% at 0.2-0.5 ml/kg 1
• Caution: Combined use of local anesthetics (e.g., lidocaine with bupivacaine) may lower the threshold for neurologic complications, especially in elderly patients 2

Safety Considerations

Maximum Dose Limits

• Without epinephrine: Maximum dose of bupivacaine is 1.3 mg/kg 1
• With epinephrine: Maximum dose of bupivacaine is 3.0 mg/kg 1
• Note: Lower doses should be used in very vascular areas 1
• For pediatric patients under 6 months, doses of amide local anesthetics should be decreased by 30% 1

Concentration Conversion

• 0.25% bupivacaine = 2.5 mg/ml 1
• Always calculate the total dose in mg/kg to ensure it remains below the toxic threshold 3

Special Considerations

Age-Related Dosing (if applicable)

• Adults: Standard dosing as above 1
• Children (age-based dosing for reference):
  • 1-5 years: 150-200 micrograms/kg (max 10mg) every 4-6 hours 1
  • 5-18 years: 200-300 micrograms/kg single dose adjusted according to response 1

Technique Comparison

• Periosteal blocks may provide inferior analgesia compared to IVRA (intravenous regional anesthesia) but can be an alternative when IVRA cannot be performed 4
• For completely displaced fractures in children, general anesthesia with potential K-wire fixation may be preferable to hematoma blocks due to higher redisplacement rates with the latter 5

Toxicity Management

• Be prepared to manage local anesthetic systemic toxicity (LAST) 1
• Treatment protocol includes:
  • Airway management and 100% oxygen 1
  • Seizure management with benzodiazepines (e.g., midazolam 0.1-0.2 mg/kg IV) 1
  • Lipid emulsion therapy (1.5 ml/kg 20% lipid emulsion) for cardiovascular collapse 1

Common Pitfalls to Avoid

• Exceeding maximum recommended doses even when combining different local anesthetics 1, 2
• Failure to aspirate before injection, which increases risk of intravascular administration 3
• Inadequate monitoring for signs of local anesthetic toxicity, especially in elderly patients 2
• Using deep sedation or local hematoma block for completely displaced fractures in children, which may lead to higher redisplacement rates 5