Discussion
postoperative nausea and vomiting
Our data on the need for additional anesthesia during surgery (84.2% efficiency) are comparable to those obtained by Gautier et al. in the subarachnoid use of levobupivacaine in caesarean section, where its efficiency was 80%However, other studies have shown high efficacy of levobupivacaine in subarachnoid useTime of sensory block development in our study was statistically significantly faster in bupivacaine group than in levobupivacaine group (4 (3; 5) min vs. 9 (5; 14) min), which is consistent with the data obtained in other studiesEfficiency of development of complete motor block in levobupivacaine group was 86.8%, and significantly different from bupivacaine group. These data are consistent with previous studiesIn our study we obtained no significant differences in the duration of postoperative analgesia. These results are similar to the results of other studiesThe authors of a major review found little evidence for the need to switch to general anesthesia and adjuvant analgesia between hyperbaric or isobaric bupivacaine groups. This is due to the rarity of these results, variability in doses, use of adjuvant drugs, and differences in regional anesthesia techniques. Any possible, in the authors' opinion, benefits of hyperbaric bupivacaine should be confirmed in larger randomized trials. In future studies, the criteria for switching to general anesthesia should be defined objectively and applied uniformlyAccording to Heng Sia et al. there is no clear evidence of superiority of hyperbaric anesthesia over conventional bupivacaine for spinal anesthesia in cesarean sectionAt the same time, a study published in 1984 showed fewer failures when using hyperbaric solution than isobaric solutionAccording to other authors, levobupivacaine was not inferior to bupivacaine in quality of motor block, but anesthesia duration was longer when bupivacaine was usedIn Huang et al. study, it was noted that when using hyperbaric bupivacaine 0.5% intrathecally, about 70% of sensory block variants can be predicted. And about 30% are incomprehensible variants and they require studyThe limitations of the study are that we did not compare the hemodynamic effects of the three drugs, nor did we evaluate study groups for the development of postoperative nausea and vomiting.In conclusion, our study determined 83.7% efficacy of levobupivacaine and 72.9% efficacy of hyperbaric bupivacaine compared with isobaric bupivacaine (100%) when administered intrathecally in equal volumes and amounts (according to the criteria of additional intraoperative analgesia). The slowest development of sensory and motor block was noted in levobupivacaine. The longest postoperative analgesia was observed for isobaric bupivacaine and levobupivacaine. It should be noted that the data of different authors on the efficacy of levobupivacaine and hyperbaric bupivacaine are contradictory. Further studies with large numbers of patients are needed to determine whether levobupivacaine and hyperbaric bupivacaine can be equal to bupivacaine in efficacy.