Determine the effectiveness of post-operative pain management of ultrasound guided transversus abdominis plane block vs open internal transversus abdominis plane block following abdominal hysterectomy a randomized controlled study

Abstract

<strong>Introduction:</strong> Abdominal hysterectomy is a common surgical procedure associated with considerable post-operative pain. The surgical outcomes are generally improved when pain control is optimized in the postoperative period. The transversus abdominis plane (TAP) block is an evolving regional anesthetic technique which provides analgesia to the skin, muscle and parietal peritoneal layers of anterior abdominal wall leading to reduction of post-operative pain. Objectives: To compare the effectiveness in reducing postoperative pain between ultrasound guided TAP block, open internal TAP block and without TAP block in patients undergoing abdominal hysterectomy under general anaethesia. <strong>Methods:</strong> Three-armed randomized case control prospective study conducted in Teaching Hospital Kandy from August 2016 to May 2017. Sixty six (66) patients scheduled and admitted for abdominal hysterectomy via supra- pubic transverse incision under general anaesthesia, aged between 40-60 years were included. Block randomization technique was applied to achieve the allocation concealment. There were 22 participants in each group of each arm. The Group 1 received USS guided TAP block, Group 2 open TAP block and Group 3 neither TAP block administered. The key data collected by a blinded observer at 12, 24 and 48 post-operative points were analgesic requirements and the analogue pain scale measurements of post-operative pain. These were compared in three groups. 95% confidence interval and 0.05 probability cut off were used to determine statistical significance. <strong>Results:</strong> The Mean age of the all participants was 51.98 years (SD=8.36) and length of the surgical incision ranged from 10cm to 13cm. Mean weight of participants was 60.69kg (SD - 7.0kg). Majority of the surgeries were completed in less than 45 minutes (n=42:63.6%). There was no significant difference in above three measurements in the three groups. The difference in mean pain score in all 3 study groups were statistically significant at time points of 12, 24 and 48 hours (F=15.45-12H: F=12.63-24H: F=7.67-48H). The difference in mean Pethidine requirement in all 3 study groups were statistically significant at 3 time points of 12, 24 and 48 hours (F=20.71-12H: F=14.4-24H:F=10.52-48H). The difference in mean NSAID requirement in all 3 study groups at 24- and 48-hour study points studied were statistically significant (F=5.98-24H: F=8.07-48H). <strong>Conclusions: </strong>In abdominal hysterectomy the pain score, Pethidine and NSAID requirement was less, in participants who received an USS TAP block and an Open TAP block as a post-operative pain relief method when compared with participants who did not receive either. However, the data did not confirm that one TAP block is statistically superior to other. More detail experimental studies should be planned to evaluate the effectiveness of post-operative pain relief of TAP blocks during open abdominal hysterectomy and TAP blocks compared with existing post-operative pain relief protocols.