Surgeons or anesthesiologists perform transversus abdominus plane (TAP) blocks as an important adjuvant analgesic for bariatric patients. This study compared the effectiveness of surgeon (SURG) vs. Anesthesiologist (ANES) TAP blocks, and no TAP blocks after bariatric surgery by analyzing postoperative narcotic use and length of stay (LOS).
This was a retrospective study at a single academic hospital of patients undergoing bariatric surgery (10/2019-11/2020) comparing three groups: 1) laparoscopic-guided intraoperative blocks (SURG), 2) ultrasound-guided perioperative blocks (ANES), and 3) no TAP block. SURG techniques varied, but used one formulation (38ml 0.375% Bupivacaine + 8mg Dexamethasone). ANES techniques and formulation varied with an average 30ml 0.25% Bupivacaine + Lidocaine. Statistical analysis was performed by univariate ANOVA and with post-hoc Fisher-LSD comparisons. Pearson's r was calculated to correlate Morphine Milligram Equivalent (MME) use and LOS (days).
Overall, 224 patients were identified within SURG (n=45), ANES (n=20), and no TAP (n=159) groups. Surgeon TAP blocks were associated with significantly less postoperative MME use overall (p=0.0135) and when compared to ANES and no TAP blocks (Figure 1A). There was a trend toward decreased LOS following SURG vs. ANES and no TAP blocks, respectively (not shown). The correlation between postoperative MME use and LOS was significant (r=0.375, p=0.001;Figure 1B).
Surgeon TAP blocks resulted in significantly reduced postoperative narcotic use possibly due to specific formulation along with advanced knowledge of port site location leading to more precise technique. Next steps include provider education, standardization of block administration, and larger data collection efforts.