Comparison of the efficacy of 0.5% isobaric bupivacaine, 0.5% levobupivacaine, and 0.5% hyperbaric bupivacaine for spinal anesthesia in lower limb surgeries.

Various advantages of isobaric bupivacaine, levobupivacaine, and hyperbaric bupivacaine are described. There are no studies reliably determining the benefits of these forms of bupivacaine. The purpose of the study was to compare the efficacy of spinal anesthesia (SA) performed with 0.5% isobaric bupivacaine, 0.5% levobupivacaine, and 0.5% hyperbaric bupivacaine. The clinical study was approved by the ethics committee. The sample size was calculated for a confidence level of 99%. 111 patients were randomly allocated into 3 equal groups for spinal anesthesia in lower limb surgeries. In group 1 (1B) spinal anesthesia was performed with 3 ml of 0.5% isobaric bupivacaine (n = 37); in group 2 (2L)-3 ml of 0.5% levobupivacaine (n = 37), in group 3 (3H)-3 ml of 0.5% hyperbaric bupivacaine (n = 37). The criterion for assessing the effectiveness of anesthesia was the need to switch to another type of anesthesia (criterion-no anesthesia), or the need for additional use of narcotic analgesics or local anesthesia during surgery (criterion-reporting of painful feelings during the operation). In 1B anesthesia efficiency by the criterion of additional intraoperative analgesia was 100% (37 patients; 95% CI [0.88-1.0]); 2L-86.4%; (31 patients; 95% CI [0.68-0.92]); 3H-72.9% (27 patients; 95% CI [0.56-0.84]). There were significant differences between groups 1B and 2L: p < 0.05 (p = 0.0104). There were no significant differences between groups 2L and 3H (p = 0.2587). All patients in group 1B developed complete sensory block (++) within 4 (3; 5) min. In group 2L complete sensory block developed in 34 patients (89.4%) within 9 (5; 14) min, in group 3H sensory block developed in all patients within 3 (2.5; 4). The duration of analgesia period between 1B and 2L did not statistically differ (p = 0.73). In 3H the duration of analgesia was 170 (150; 200) min. The study found 83.7% efficacy of levobupivacaine and 72.9% efficacy of hyperbaric bupivacaine in comparison with isobaric bupivacaine (100%) when administered intrathecally in equal volumes and amounts (by the criterion of additional intraoperative analgesia).Trial registration: NCT05184465 (Initial Release: 12/01/2021; date of first publication-11/01/2022).