BACKGROUND: The transversus abdominis plane (TAP) block has been shown to provide effective postoperative analgesia in lower abdominal surgery. Subcostal TAP block has also been proposed as a new technique to provide analgesia for the supraumbilical abdomen. We compared the analgesic and opioid-sparing effects of a single-injection subcostal TAP block with continuous thoracic epidural analgesia and IV opioid analgesia.
METHODS: Ninety patients undergoing elective radical gastrectomy were randomized to receive either combined general–subcostal TAP anesthesia (group TAP), combined general–epidural anesthesia (group EA), or general anesthesia (group GA), and were analyzed on an intention-to-treat basis. In group TAP, a bilateral subcostal TAP block was performed after induction of general anesthesia using 20 mL of 0.375% ropivacaine. In group EA, a thoracic epidural was placed between T8 and T9 and bolused with 8 mL of 0.25% ropivacaine before induction of general anesthesia. The epidural was maintained with 5 mL/h of 0.25% ropivacaine during the surgery. Group GA received standard general anesthesia. In the postanesthesia care unit (PACU), all groups received IV morphine titration for visual analog scale (VAS) pain scores >3. All patients were started on IV patient-controlled analgesia with morphine after morphine titration in the PACU, while group EA also had their epidural maintained with 5 mL/h of 0.125% bupivacaine with 8 μg/mL morphine. Patients were assessed in the PACU and at 1, 3, 6, 24, 48, and 72 hours postoperatively. Primary outcomes measured were morphine consumption at 24 hours and all VAS pain scores.
RESULTS: Data from 82 of 90 (91.1%) patients were included in the study. Group TAP demonstrated decreased cumulative morphine consumption at 24 hours (98.75% confidence intervals, −29 to −9 mg) and noninferiority on VAS pain scores at all measurement times, as compared with group GA with standard opioid analgesia. However, group EA was superior to group TAP regarding cumulative morphine consumption at 24 hours (98.75% confidence intervals, −23 to −4 mg) and noninferior to group TAP on VAS pain scores at all comparison points. Group TAP had reduced morphine consumption from PACU admission to 6 hours as compared with group GA, but increased morphine consumption for 6 to 24 hours as compared with group EA.
CONCLUSION: Single-injection subcostal TAP block was more effective than IV opioid analgesia, while continuous thoracic epidural analgesia was more effective than the single-injection subcostal TAP block.