Trans-Abdominis Plane Block Efficacy for Post-Cesarean Section Pain

• Status: Withdrawn
• Trial end date: 2013-09-01
• Target enrollment: 0
• Participant gender: Female

Summary

The primary aim of this study is to measure the magnitude and duration of trans-abdominis plane (TAP) block analgesia in parturients undergoing elective cesarean section with concurrent standard of care operative analgesic regimens including intrathecal morphine sulfate (ITMS). A one sided block model takes advantage of the bilateral nature of the pain created by a bilateral surgical wound and allows each patient to serve as her own control. Reduced variability allows a more definitive establishment of analgesic benefit for this block.

The current reports of conflicting data regarding efficacy make uncertain the role of TAP block in post cesarean section pain relief. This model would have a better potential for measuring the block's effectiveness. Quantitative sensory evaluation tools such as the von Frey hair tool provides a quantitative reproducible measure of skin sensation and also allows for assessment of block regression over time. Pressure algometry has been established as a clinical and research tool for quantitative assessment of pain levels in multiple pain conditions. A useful inexpensive reliable pressure algometer has recently been described.

The assessment of serum ropivicaine levels with this block will provide useful data regarding the systemic absorption of local anesthetic compared to other peripheral nerve blocks and establish the safety of the technique.

In addition this study will help establish a model for the study of TAP block modifications in the future. If block effectiveness is demonstrated, this model can be used to examine numerous block parameters including choice of local anesthetic and dose response analysis for optimal volume and concentration. Potential future study may be done also in the area of adjuncts found to have increased duration and effectiveness as used in other peripheral nerve blocks.

Expected duration of this study is 18 months.

• Phase: N/A
• Accepts Healthy Volunteers?: No

Details

• Lead Sponsor: Vanderbilt University; Vanderbilt University Medical Center
• Treatments: Ropivacaine

Criteria

Inclusion Criteria:

• Singleton pregnancy

• Pre-pregnancy body mass index less than or equal to 35

• Elective repeat cesarean section under SAB or CSE (patients in whom the epidural catheter is activated intra-operatively will be excluded)

• English-Speaking patient

• Age at least 18 and no more than 40 years old.

Exclusion Criteria:

• Chronic pain or daily consumption of pain medications

• Neurologic disorders producing altered sensory perception or impaired motor strength in lower extremities or abdomen

• Pre-existing epidural analgesia infusion for labor analgesia.

• Spinal anesthetic failure requiring epidural catheter use or general anesthesia

• Intra-operative conversion to general anesthesia for fetal indications.

• Cesarean section performed with a vertical (not Phannenstiel) incision