Abstract Background: Patients with chronic renal insufficiency need to have arteriovenous fistula (AVF) for hemodialysis.Ultrasound guided axillary brachial plexus block is a good substitute to general anesthesia or local anesthesia as it causes vasodilatation and minimum hemodynamic derangement, besides offering prolonged postoperative analgesia. We compared three types of local anesthetic solutions; bupivacaine 0.5%, bupivacaine 0.5% plus lidocaine2% and lidocaine 1.5% for onset and duration when used for axillary brachial plexus block. Methodology: Sixty-six patients were randomly allocated to one of the three different groups: Group B: patients  received 30 ml of bupivacaine 0.5% for the block; Group BL: received 15 ml of bupivacaine 0.5% with 15 ml lidocaine 2% and Group L: received 30 ml of lidocaine 1.5% for the block under US guidance. Onset of sensory and motor anesthesia were registered, and the time to first analgesic demand postoperatively was noted. Statistical analysis of the results was undertaken. Results: Results showed that regarding the onset of sensory anesthesia, lidocaine group had the shortest time and the results were statistically significant compared to the other two groups. A statistically non-significant difference was found between Group B and Group BL, where Group BL had shorter time of onset than Group B, e.g., 9.05 ± 1.36 vs. 9.77 ± 0.97 min. The onset of motor block was the earliest in Group BL and the result was considered nonsignificant between Group L and Group B being shorter in Group L; the difference in results was also non-significant between Group BL and Group L. Significantly longer duration of motor and sensory blocks was noted in Group B and compared to the BL and L groups. As regards the timing of first analgesic need, there was statistically significant difference between all groups being longest in Group B (608.68 ± 21.74 min) Conclusion: This study revealed that using 30 ml of bupivacaine 0.5% in axillary brachial plexus block with ultrasound guidance in ESRD patients for AVF creation gives much better results than 30 ml of lidocaine 1.5% or a mixture of Abdelhady ISM, et al local anesthetics for axillary brachial plexus block www.apicareonline.com 744 Open access attribution (CC BY-NC 4.0) bupivacaine 0.5% with lidocaine 2% as regards to onset of anesthesia, postoperative analgesia and patient satisfaction. Trial Registry: PACTR202208582938205 Abbreviations: AVF: arteriovenous fistula; BPB: Brachial plexus block; ESRD: End stage renal disease; GA: General anesthesia; NRS: Numeric rating scale; RA: Regional anesthesia Key words: Bupivacaine; Lidocaine; Hemodialysis; Brachial plexus block Citation: Abdelhady ISM, Ghallab MAA, Zaki MSM, Abdelrahman KAS, Soliman AFH. Comparative study between bupivacaine 0.5% vs. bupivacaine 0.5% plus lidocaine 2% vs. lidocaine 1.5% in ultrasound guided axillary brachial plexus block for brachiocephalic fistula formation in chronic renal failure patients. Anaesth. pain intensive care 2022;26(6):743−748; DOI: 10.35975/apic.v26i6.2055 Received: September 14, 2022; Reviewed: October 28, 2022; Accepted: October 31, 2022

Background & objective: Transversus abdominis plane (TAP) block using local anesthetics is associated with relatively shorter duration of action, and thus additional analgesic drugs are required in the postoperative period. We compared the efficacy and duration of postoperative analgesia achieved with using dexmedetomidine or dexamethasone as adjuvants to bupivacaine in TAP block for lower abdominal surgeries. Methodology: We enrolled 45 adult patients aged from 20-60 y, and randomly divided them into three equal groups. Group A received ultrasound guided TAP block with 0.25% bupivacaine 20 ml plus 4 mg dexamethasone on each side. Group B received 0.25% bupivacaine 20 ml plus dexmedetomidine 0.5 µg/kg on each side, and Group C (control group) patients received only 0.25% bupivacaine 20 ml on each side. Postoperative pain was assessed with VAS on arrival in post-anesthesia care unit (PACU), at 2 h, 6 h, 12 h, 18 h, and at 24 h postoperatively. Duration of analgesia was the time from drug injection to the time of first rescue of analgesia was recorded. Results: Mean duration to first dose of rescue analgesia among patients of dexmedetomidine group (Group B) was significantly prolonged as compared to dexamethasone group and bupivacaine only group. Regarding postoperative pain scores there were no statistically significant difference between the three groups; except at 6 h between the A and B groups and the control group. Both dexamethasone group and dexmedetomidine group showed better pain control than bupivacaine only at 6 h interval. Conclusion: Dexmedetomidine added to bupivacaine in ultrasound-guided transversus abdominis plane block for postoperative pain relief in patients undergoing lower abdominal surgeries prolongs the time to initial postoperative pain presented by time to first rescue analgesic demand than dexamethasone added to bupivacaine; the shortest time to first rescue analgesic was observed in bupivacaine alone group. Abbreviations: TAP: Transversus abdominis plane block; LA: Local anesthetic; PACU: Post anesthesia care unit; VAS: Visual Analogue Scale; ASA: American Society of Anesthesiologists; SD: Standard deviation; IQR: Inter quartile range. Citation: Sobhy YS, Gadalla RR, Nofal WH, Saleh MAE, Abdou KM. A comparative study between the use of dexmedetomidine .vs dexamethasone as adjuvants to bupivacaine in ultrasound-guided transversus abdominis plane block for postoperative pain relief in patients undergoing lower abdominal surgeries. Anaesth. pain intensive care 2022;26(5):681–688; DOI: 10.35975/apic.v26i5.2031