Dexmedetomidine and Morphine as Additives to Intrathecal Levobupivacaine for Infra Umbilical Surgeries: Randomized Clinical Trial

Background: Postoperative pain (POP) management after infra-umbilical surgeries often involves opioids, which can cause side effects like pruritus. The use of dexmedetomidine, an α2-adrenergic agonist, as an adjunct to local anesthetics (LAs) may improve analgesia and reduce opioid use. Objective: To compare the efficacy and safety of intrathecal (IT) dexmedetomidine and morphine as additives to levobupivacaine for postoperative analgesia in infra-umbilical surgeries. Patients and Methods: Ninety adult patients (aged 20-75) scheduled for elective infra-umbilical surgeries were divided into three groups: Group M (200 µg morphine + levobupivacaine), Group D (5 µg dexmedetomidine + levobupivacaine), and Group DM (200 µg morphine + 5 µg dexmedetomidine + levobupivacaine). Spinal anesthesia (SA) was administered, and sensory and motor blocks were evaluated. Postoperative pain, rescue analgesic consumption, and adverse events were monitored. Results: Insignificant differences were observed in the onset of sensory or motor block between groups. However, the total duration of motor block was significantly increased in Group DM (220.7 ± 18.9 min) compared with Group M (150.2 ± 32.1 min, P = 0.001). Pruritus was more common in Group M (P = 0.04), while insignificant differences were demonstrated for other adverse events comprising nausea, vomiting, hypotension, or bradycardia. Morphine consumption via PCA was lower in Group D (10.5 ± 3.3 mg) and Group DM (10.21 ± 3.3 mg) compared to Group M (11.13 ± 5.2 mg, P < 0.05). There were significant reductions in VAS scores in Groups D and DM up to 36 hours postoperatively. Conclusion: Adding dexmedetomidine to morphine and levobupivacaine enhances postoperative analgesia, prolongs motor block, and reduces opioid consumption without compromising hemodynamic stability, suggesting its potential as a safer and more effective analgesic option.