Sydney Pinch, BS1, Tjasa Hranjec, MD2, Sara A Hennessy, MD1. 1UT Southwestern Medical Center, 2Memorial Healthcare System
Introduction: A transversus abdominis plane (TAP) block is an ultrasound-guided injection of local anesthetic in the plane between the internal oblique and transversus abdominis muscles to interrupt innervation to the abdominal skin, muscles, and parietal peritoneum. Currently there are incongruent findings on the benefit of this regional anesthetic to surgical patients, particularly the obese population. We hypothesized the addition of a TAP block in an enhanced recovery pathway (ERAS) for bariatric patients would decrease opioid use and shorten hospital length of stay.
Methods: A retrospective review of all patients who underwent bariatric surgery at a single institution from January to December 2016 was performed. Patients were identified as: no TAP block (No TAP), TAP blocks that were performed after induction either pre-surgery (Pre-TAP) or post-surgery (Post-TAP). The primary outcome was time to first opioid (min) and total morphine (mg) equivalents in PACU. The secondary outcome was hospital length of stay (LOS) and 30-day readmission. Patients were compared on pre-operative and intraoperative factors by univariate analysis using Wilcoxon rank sum, Chi-square, and Fisher’s exact tests where appropriate.
Results: A total of 129 bariatric procedures were performed of which 105 underwent a TAP block; with 81 Pre-TAP block patients and 23 Post-TAP block patients. In PACU, average morphine (mg) equivalent was calculated as No TAP of 10.4 ± 8.1, Pre-TAP of 7.4 ± 7.3, Post-TAP of 7.7 ± 8.2mg (p= 0.33). There was no significant difference in time (min) to first opioid in PACU (No TAP 29.1 ± 20.9, Pre-TAP 26.8 ± 21.8, Post-TAP 26.1 ± 18.4). Length of stay (days) was not significantly different between No TAP, Pre-TAP and Post-TAP block patients (3.0 ± 2.2 vs. 2.6 ± 5.4 vs. 3.2 ± 5.9). Finally, there was also no difference in 30-day readmission between No-TAP, Pre-TAP and Post-TAP patients (5.9% vs. 4.9% vs. 0%).
Conclusion: The addition of a TAP block to our ERAS pathway for bariatric patients failed to reduce use of opioids or decrease hospital length of stay and 30 day readmission. The failure to show any significant differences may be attributed to our small study population. However, in the TAP block group opioid use was lower by 3 mg and with nearly half the number of readmissions. The potential for a positive impact with minimal risk of a TAP block is an important reason to continue to prospectively study the impact of TAP blocks on bariatric surgery patients.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 88571
Program Number: P363
Presentation Session: iPoster Session (Non CME)
Presentation Type: Poster