Comparative characteristics of the effectiveness of spinal anesthesia with intrathecal administration of bupivacaine and its combination with adjuvants

Background. Currently, there is active discussion regarding the effectiveness of different adjuvants in spinal anesthesia. Objective: to compare the effectiveness of dexmedetomidine and fentanyl as adjuvants in combination with intrathecal bupivacaine administration during biportal endoscopic discectomy. Materials and methods. The study included 150 patients. Using block randomization based on a sample size, patients were divided intro the following groups: 1) group 1 — intrathecal hyperbaric bupivacaine 2.5 ml in 0.5 ml of normal saline; 2) group 2 — intrathecal hyperbaric bupivacaine 2.5 ml with fentanyl 25 µg; 3) group 3 — intrathecal hyperbaric bupivacaine with dexmedetomidine 5 µg. Results. A faster onset of a sensory block up to T8 was observed in group 3 (4.39 ± 0.90 minutes), which was 20.9 ± 1.4 % earlier compared to group 1, where this parameter was 5.55 ± 1.37 minutes (p = 0.00124). When comparing similar data between groups 2 and 3, no statistically significant difference was observed (p = 0.68135). The time to two-segment regression from the highest sensory level was highest during the administration of bupivacaine with dexmedetomidine (group 3), 147.39 ± 24.95 minutes. A similar trend was maintained in the time indicators of sensory regression to S1 from the highest sensory level. The time to Bromage 0 regression in the bupivacaine with dexmedetomidine group (group 3) was on average 90.52 ± 3.25 % higher compared to the bupivacaine and fentanyl group and exceeded similar values in the bupivacaine with normal saline group (group 1) by 133.55 ± 4.18 %. The overall duration of analgesia was highest in group 3 — 482.63 ± 66.85 minutes. This was on average 67.39 ± 2.75 % longer compared to group 2 and 119.55 ± ± 4.14 % longer compared to group 1 (p < 0.001). The pain severity 6 hours after surgery was the lowest in the group of bupivacaine and dexmedetomidine (group 3) — 2.05 ± 0.79 that was 67.04 ± 2.51 % lower than the corresponding value in the bupivacaine and fentanyl group (group 2) and 68.27 ± 2.35 % lower than in the bupivacaine with normal saline group (group 1). Conclusions. Intrathecal administration of hyperbaric bupivacaine with dexmedetomidine 5 µg during spinal anesthesia has the maximum effect in terms of deve-loping motor and sensory blocks, prolongs postoperative analgesia, and reduces the need for postoperative use of narcotic analgesics.