Comparison of QLB block and TAP block in morbid obese patients: a randomized controlled study

Quadratus lumborum block (QLB) and Transverses abdominis plane block (TAP) are a fascial plane block. The study aimed to compare the efficacy of the TAP block and QLB-2 in terms of postoperative pain assessed by the VAS and morphine consumption following laparoscopic sleeve gastrectomy. This study was conducted as a randomized controlled trial involving patients who underwent laparoscopic sleeve gastrectomy in the operating room. Patients were randomly assigned to one of three groups: groups 1 (TAP block), 2 (QLB-2 block), and 3 (control). Analgesic consumption was assessed by evaluating morphine use at the postoperative 1st, 6th, 12th, and 24th hours, as well as the total morphine consumption and VAS scores. Quality of life was preoperatively evaluated, at 48 h, and 1 week using the WHOQOL-BREF scale. One hundred twenty-six patients (female:103 and male:23) were included in the final analysis (44, 42, and 40) in the control, TAP and QLB-2 block groups, respectively. The block duration in the QLB-2 group was significantly longer than that in the TAP block group ( p = 0.001). Total morphine consumption differed between the groups ( p = 0.001). Morphine consumption in the TAP block group was lower than that in the control ( p = 0.001) and QLB-2 ( p = 0.001) groups. The total morphine consumption in the QLB-2 group was also significantly lower than that in the control group ( p = 0.035) − 0.001) and QLB-2 ( p = 0.019) groups. WHOQOL scores (48 h and 1 week postoperatively) were no statistical differences in any subgroup or timeline ( p > 0.05). There was a statistically significant difference in postoperative VAS scores (1st, 6th, 12th and 24th hours) among the study groups ( p < 0.001). TAP and QLB-2 blocks were associated with reduced postoperative pain scores and opioid requirements in morbidly obese patients undergoing laparoscopic sleeve gastrectomy compared to no regional block. TAP block consumed less morphine overall, had a shorter block performance time, and mobilized earlier than QLB-2 block. There were no changes in quality of life outcomes and it was no statistically significant difference in the preoperative VAS scores between the study groups. ClinicalTrials.gov (Registration No: NCT05820620). Date of registration: 27/03/2023.