The analgesic efficacy of transversus abdominis plane (TAP) block after total abdominal hysterectomy: a randomized controlled trial

Objective: To assess the effectiveness of surgical TAP block in providing post-operative analgesia in women undergoing total abdominal hysterectomy through supra pubic transverse incision under general anaesthesia Design: A randomized controlled study Setting: Professorial Unit, Colombo South Teaching Hospital, Kalubowila Population: A total of forty women scheduled to undergo total abdominal hysterectomy for benign conditions Methodology: Women were randomized and the intervention arm received TAP block. Both arms received standard analgesia. The pain was assessed by visual analogue pain score at specific time intervals. Main outcome measure: Requirement of pethidine for pain relief for 24 hours and assessment of post-operative pain using a visual analogue scale at specific intervals up to 24 hours Results: Compared to controls, in women who received TAP block, there was a statistically significant reduction in pain at 30 minutes (pain score 4.5+1.3 vs. 5.4+1.0, p=0.02), at 1h (4.4±1.0 vs. 5.2±0.7, p=0.01), at 2h (4.0±0.9 vs. 4.8±0.7, p=0.01), at 3h (3.6±0.8 vs. 4.3±0.7, p=0.01), at 6hrs (2.8±0.9 vs. 3.0±0.7, p=0.001), and at 12hrs (2.1±1.0 vs. 3.0±0.9, p=0.01). At 24hrs, there was no significant difference in pain reduction. (1.4±0.5 vs. 1.8±0.7, p=0.11). The cumulative morphine requirement was also significantly less in the TAP group at all the time points. Conclusion: The TAP block provided highly effective postoperative analgesia following total abdominal hysterectomy and the cumulative morphine requirement was also significantly less in the TAP group at all the time points. It should be considered as part of a multimodal approach to anaesthesia and enhanced recovery in patients undergoing abdominal surgery. DOI: http://dx.doi.org/10.4038/sljog.v36i1.6954 Sri Lanka Journal of Obstetrics and Gynaecology 2014; 36: 5-10