To Compare The Efficacy And Safety Of Different Doses Of Intrathecal Dexmedetomidine 3mcg And 5mcg As An Adjuvant Combined With Hyperbaric Ropivacaine 12.5mg In Patients Undergoing Peri-Anal Surgeries

Abstract

Background: Effective regional anesthesia is essential for perianal surgeries to ensure patient comfort and facilitate rapid postoperative recovery. Hyperbaric ropivacaine, commonly used for spinal anesthesia, offers a favourable safety profile. Dexmedetomidine, a selective α₂-adrenergic agonist, is frequently used as an adjuvant to enhance analgesia quality and prolong its duration. However, the optimal intrathecal dexmedetomidine dose when combined with hyperbaric ropivacaine for perianal surgeries remains underexplored.
Objectives: This study aimed to compare the effects of 3 mcg and 5 mcg doses of intrathecal dexmedetomidine combined with 12.5 mg hyperbaric ropivacaine on the duration of sensory and motor blockade, hemodynamic stability, postoperative analgesia, and adverse effects in perianal surgeries.
Methods: A prospective, randomized, double-blind clinical trial was conducted on 60 patients undergoing elective perianal surgeries. Patients were randomized into two groups: Group A received 12.5 mg hyperbaric ropivacaine + 3 mcg dexmedetomidine, and Group B received 12.5 mg hyperbaric ropivacaine + 5 mcg dexmedetomidine. Parameters assessed included onset and duration of sensory and motor blocks, time to first analgesic request, hemodynamic changes, and sedation scores.
Results: Group B exhibited a faster onset of sensory (5.1 ± 0.5 min) and motor block (6.0 ± 0.6 min), and significantly prolonged durations of sensory (280 ± 6 min) and motor block (255 ± 7 min) compared to Group A (p < 0.001). Time to first analgesic request was longer in Group B (570 ± 10 min vs. 490 ± 6 min; p < 0.001). However, Group B experienced greater hemodynamic changes, including lower blood pressure (p = 0.003) and heart rate (p = 0.001). Sedation scores were comparable between groups (p = 0.82).
Conclusion: For perianal surgeries lasting 60–90 minutes, optimal sensory blockade with minimal hemodynamic effects and desired sedation is crucial. A 3mcg dose of intrathecal Dexmedetomidine with 12.5mg Ropivacaine provides adequate motor blockade, superior analgesia, and minimal or no hemodynamic changes. Higher doses require careful patient selection and monitoring to ensure safety.