What is the recommended dosing for bupivacaine and Exparel (bupivacaine liposome injectable suspension) for a rectus sheath block?

Dosing of Bupivacaine and Exparel for Rectus Sheath Block

For rectus sheath blocks, use 0.25% bupivacaine at a dose of 0.1 ml/kg bilaterally (total dose not exceeding 2.5 mg/kg) or Exparel (bupivacaine liposome injectable suspension) following manufacturer's guidelines for peripheral nerve blocks. While specific rectus sheath block guidelines are limited, evidence from clinical practice provides direction.

Standard Bupivacaine Dosing

• The American Society of Anesthesiologists recommends 0.25% as the standard concentration of bupivacaine for peripheral nerve blocks 1
• For rectus sheath blocks, clinical evidence supports using 0.25% bupivacaine at a volume of 0.1 ml/kg bilaterally 2
• The maximum dose of bupivacaine 0.25% for peripheral nerve blocks should not exceed 2.5 mg/kg to prevent local anesthetic toxicity 3
• Ultrasound guidance is recommended for accurate placement between the posterior rectus sheath and rectus abdominis muscle 2

Clinical Evidence for Bupivacaine in Rectus Sheath Blocks

• Studies have demonstrated that bilateral placement of 0.1 ml/kg of 0.25% bupivacaine (or levobupivacaine) provides sufficient analgesia for umbilical hernia repair 2, 4
• For laparoscopic procedures, 10 ml of 0.25% bupivacaine on each side (total 50 mg) has been shown to reduce oral analgesic requirements and prolong time to first analgesic request 5
• Alternative local anesthetics such as 0.5% ropivacaine at 10 ml bilaterally have also demonstrated efficacy in reducing postoperative pain after laparoscopic surgery 6

Exparel (Bupivacaine Liposome) Considerations

• When using Exparel (bupivacaine liposome injectable suspension), follow manufacturer's specific guidelines for peripheral nerve blocks
• Unlike standard bupivacaine, Exparel provides extended release properties that can prolong analgesia
• Caution: Do not mix Exparel with standard bupivacaine in the same syringe as this may affect the release profile

Technical Considerations

• Ultrasound guidance is strongly recommended for rectus sheath blocks to ensure accurate placement and efficacy 2
• The depth of the posterior rectus sheath can be unpredictable in patients, making ultrasound guidance particularly valuable 2
• The block should be placed in the space between the posterior aspect of the rectus sheath and the rectus abdominis muscle 2

Safety Considerations

• Always calculate the total dose in mg/kg to ensure it remains below the toxic threshold 3
• Aspirate before injection to avoid intravascular administration 3
• Consider using a test dose with epinephrine to detect intravascular injection 3
• Monitor patients for signs of local anesthetic systemic toxicity after block placement

Common Pitfalls

• Exceeding maximum safe dose when using higher concentrations 7
• Failure to adjust volume when increasing concentration 7
• Inadequate monitoring for systemic toxicity 7
• Incorrect placement of local anesthetic (superficial to the posterior rectus sheath rather than deep to it) 2