TAP Block for Postoperative Pain Control

This clinical trial will examine differences in the effectiveness between three (3) commonly used methods and/or medications used to perform a transversus abdominis plane (TAP) block for post-operative pain control. The transversus abdominis muscle is either side between the lowest rib and the hip bone. Group A subjects will undergo post-operative pain relief treatment with a single injection of Bupivacaine injected into the TAP. Group B subjects will undergo post-operative pain relief treatment with a single injection of Exparel®, a liposomal form of bupivacaine into the TAP. Group C subjects will be treated with a continuous infusion of the local anesthetic ropivacaine with the ON-Q® pump. There will be no placebo group in this study.

Subjects will undergo post-operative pain relief treatment with a single injection of Bupivacaine, a local anesthetic injected into the transversus abdominis plane.

Subjects will undergo post-operative pain relief treatment with a single injection of Exparel®, a liposomal form of bupivacaine, into the transversus abdominis plane

Subjects will be treated with a continuous infusion of the local anesthetic Ropivacaine with the ON-Q® pump

60 ml Bupivacaine 0.25% will be drawn via 60 ml Syringe. The syringe will be connected and a 10ml flush syringe containing 10ml 0.9% Normal Saline (NS) will be connected to the end of an IV extension set via a 3-way stopcock and Luer lock connections. The Bupivacaine 0.25% syringe will be connected to the stopcock. The distal end of the IV connection will be connected to the injection needle. The entire setup will be flushed with 0.9% NS via flush syringe. The TAP space will also be located under ultrasound guidance and verified by using the 0.9% NS flush syringe. Once in the TAP space, 30 ml Bupivacaine 0.25% will be injected into the TAP space. This dose will be decreased to 25 ml for patients under 70 kg. The process will be repeated on the opposite side TAP block.

20 ml Exparel (266 mg) will be drawn into a 20 ml syringe. A 20 ml Bupivacaine 0.25% syringe and the syringe containing the Exparel solution will be connected to the end of an IV extension set via a 3-way stopcock. The IV connection will be connected to the injection needle. The setup will be flushed with the Bupivacaine syringe. The TAP space will be located under ultrasound guidance. 133mg of Exparel will be injected into the TAP space. After injection, the syringe will be exchanged for the Bupivacaine syringe and 20ml Bupivacaine injected into the space. The process will be repeated on the opposite side TAP block.

40 ml Bupivacaine 0.25% will be drawn via two 20ml Syringes. A Bupivacaine 20ml syringe will be connected to an IV extension via a 3-way stopcock and Luer lock. The IV will be connected to an injection tuohy needle and flushed with NS. The TAP space will be located using ultrasound guidance. 15 ml Bupivacaine 0.25% will be injected. A catheter will be threaded through the tuohy needle into the TAP space. 5ml Bupivacaine 0.25% will then be injected. The catheter will be secured via standard technique. The process will be repeated for the opposite side. Patients will receive a filled ON-Q system. The ON-Q system contains Ropivacaine 0.2%. The pump will run at 7 ml/hr. per side.

The total use of analgesic medications will be recorded during the 3 days immediately following surgery.

Patients will rate their pain by VAS scale 1 day post surgery. Scale is a 0 to 10 visual analog scale with 0 representing no pain and 10 representing severe pain.

Patients will rate their pain by VAS scale 2 days post surgery. Scale is a 0 to 10 visual analog scale with 0 representing no pain and 10 representing severe pain.

Patients will rate their pain by VAS scale 3 days post surgery. Scale is a 0 to 10 visual analog scale with 0 representing no pain and 10 representing severe pain.

Inclusion Criteria: Ability to give written informed consent Scheduled for open abdominal surgery American Society of Anesthesiologists physical status 1 to 3 Exclusion Criteria: Inability to understand the study or provide written informed consent Inability to follow protocol instructions Complicated history of chronic opioid use including daily use of opioids for a period greater than 2 weeks prior to surgery Allergy to local anesthetic agents Contraindication to regional nerve block such as: Bleeding disorder Sepsis Infection at site of block Body Mass Index (BMI) >40 Pregnancy