TAP Block for Analgesia after Cesarean Delivery
Abstract Number: S-31
Abstract Type: Original Research
Introduction: The transversus abdominis plane (TAP) block is a regional anesthetic technique that blocks sensation to the T6-L1 nerve roots to provide analgesia for lower abdominal procedures. Several studies have investigated the use of TAP blocks for analgesia following cesarean delivery (CD). We performed a meta-analysis to assess the efficacy of TAP blocks in decreasing pain scores, opioid consumption, and opioid-related side effects in parturients undergoing CD.
Methods: We searched MEDLINE, CENTRAL, EMBASE, and CINAHL for randomized controlled trials that assessed the efficacy of TAP blocks in women undergoing CD and that reported pain scores and/or opioid consumption. We compared TAP block to control and pooled studies based on the use of intrathecal morphine (ITM). We also performed an analysis comparing TAP block to ITM. Data were extracted independently by the authors. Visual analog pain scores were converted to a 0-10 scale, and analgesics were converted to morphine equivalents for analysis. A random effects model was used.
Results: Seven studies comprising 410 patients were included in the final analysis. Spinal anesthesia was used in 6 studies and general anesthesia in 1 study. All performed TAP block at the end of CD using either landmark techniques (2/7) or ultrasound guidance (5/7). Five studies included groups comparing TAP block to control without ITM (4 spinal anesthesia with intrathecal fentanyl [10-25 μg] and 1 general anesthesia); 2 studies had groups comparing TAP block to control with ITM 100 μg added to fentanyl 10 μg; and 2 studies had groups comparing TAP block to ITM 100 μg and 200 μg. The results are summarized in the table. TAP block significantly reduced opioid consumption for up to 24 h, pain scores for up to 12 h, and nausea in patients who did not receive ITM. When added to ITM, TAP block produced only a small reduction in pain scores with movement in the first 6 h. When compared to ITM, opioid consumption in the first 6 h was lower, and the time to first need for rescue analgesics was longer with ITM; however, opioid-related side effects were more common with ITM compared to TAP block.
Conclusion: TAP block significantly improved postoperative analgesia in women undergoing CD who did not receive ITM. When added to ITM, TAP block produced only a small benefit in the early postoperative period. ITM was associated with improved analgesia compared to TAP block alone at the expense of an increased incidence of side effects.