How does intravenous ondansetron affect motor and sensory block in spinal anesthesia administered with intrathecal levobupivacaine? A prospective randomized controlled study

Background: Spinal anesthesia is commonly performed in surgical procedures, and ondansetron, frequently used as an antiemetic, is often administered to manage postoperative nausea and vomiting. Given their frequent co-administration, we sought to investigate the potential effects of intravenous ondansetron on the block characteristics of spinal anesthesia performed with levobupivacaine.Materials and Method: In this prospective, randomized controlled study, forty patients were divided into two groups: Group L (spinal anesthesia with levobupivacaine) and Group OL (spinal anesthesia with levobupivacaine plus intravenous ondansetron).Results: Our findings showed that while motor block duration was similar between the groups (p>0.05), sensory block duration was significantly shorter in the ondansetron group (p<0.05). There were no significant differences in patient demographics or hemodynamic parameters between the groups (p>0.05).Conclusions: The shortened sensory block with ondansetron administration may be clinically undesirable as it could limit the intended duration of anesthesia. We recommend administering ondansetron at the end of surgery to avoid this effect. Further studies are required to confirm these findings and clarify the mechanisms involved.