Epidural Bupivacaine Dosing
For lumbar epidural anesthesia in adults, administer an initial dose of 0.5 ml/kg of 0.25% bupivacaine with a maximum of 15 ml, while thoracic epidural requires 0.2-0.3 ml/kg of 0.25% bupivacaine with a maximum of 10 ml. 1, 2
Standard Adult Dosing by Site
Lumbar Epidural
- Initial dose: 0.5 ml/kg of 0.25% bupivacaine (maximum 15 ml) 1, 2
- This translates to approximately 37.5 mg for a 70 kg patient using 0.25% concentration
- The FDA supports maximum single doses up to 175 mg without epinephrine and 225 mg with epinephrine 1:200,000 3
Thoracic Epidural
- Initial dose: 0.2-0.3 ml/kg of 0.25% bupivacaine (maximum 10 ml) 1, 2
- Lower volumes are required due to the more compact thoracic epidural space
Concentration Selection by Clinical Need
- 0.25% bupivacaine: Produces incomplete motor block, suitable when muscle relaxation is not critical 3
- 0.5% bupivacaine: Provides motor blockade but may be inadequate for operations requiring complete muscle relaxation 3
- 0.75% bupivacaine: Produces complete motor block, most useful for abdominal operations requiring complete muscle relaxation, but contraindicated in obstetrical anesthesia 3
Incremental Dosing Technique
Administer epidural bupivacaine in incremental doses of 3-5 ml with sufficient time between doses to detect toxic manifestations of unintentional intravascular or intrathecal injection. 3
- This fractional dosing approach is critical for safety, particularly with 0.5% and 0.75% solutions 3
- Repeat doses should be preceded by a test dose containing epinephrine if not contraindicated 3
Maximum Dose Limits
- Daily maximum: 400 mg in 24 hours 3
- Single doses may be repeated up to once every three hours 3
- These limits must be reduced for elderly, debilitated patients, or those with cardiac/hepatic disease 3
Special Population Adjustments
Pediatric Dosing
- Maximum dose: 1 ml/kg of 0.25% bupivacaine (equivalent to 2.5 mg/kg) 1, 2
- Caudal block: 1.0 ml/kg of 0.25% bupivacaine 1, 2
- Not recommended for children younger than 12 years based on FDA labeling 3
Weight-Based Considerations
- For patients <40 kg: Calculate doses carefully with strict attention to mg/kg limits 1, 2
- For obese patients: Use ideal body weight for dose calculations 1, 2
Labor Analgesia Specific Dosing
Epidural Approach
- Use only 0.5% and 0.25% concentrations in obstetrics 3
- Incremental doses of 3-5 ml of 0.5% solution, not exceeding 50-100 mg at any dosing interval 3
- Research supports that 0.125% bupivacaine produces equivalent analgesia to 0.25% with a 25% reduction in total dose, improving safety 4
Intrathecal Catheter After Accidental Dural Puncture
- Initial bolus: 1.25-5 mg bupivacaine combined with fentanyl 12.5-25 µg or sufentanil 2-7.5 µg 5
- Maintenance infusion: bupivacaine 0.0417-0.1% with fentanyl 2-2.5 µg/ml or sufentanil 0.75-1 µg/ml at 1-3 ml/hr 5
- For breakthrough pain: 1-2 ml of maintenance solution 5
Critical Safety Considerations
Common Pitfalls to Avoid
- Never use 0.75% bupivacaine for obstetrical anesthesia due to increased cardiotoxicity risk 3
- Avoid rapid injection of large volumes; always use fractional incremental doses 3
- Do not use multiple-dose vials containing preservatives for caudal or epidural anesthesia 3
- Never use for intravenous regional anesthesia (Bier Block) or obstetrical paracervical blocks 3
Monitoring Requirements
- Assess for signs of unintentional intravascular or intrathecal injection between incremental doses 3
- In the intrathecal catheter context after accidental dural puncture, no additional cardiovascular or respiratory monitoring beyond standard epidural practice is typically required 5