Comparison of Intrathecal Dexmedetomidine and Nalbuphine as an Adjuvant in Hyperbaric Bupivacaine for Saddle Block and Postoperative in Patients Perianal

BACKGROUND Saddle block is the most commonly used anaesthetic technique for perianal surgeries in adults. Perianal surgeries under saddle block are considered as day care surgeries. Major disadvantage is that the low volume of spinally given drug won't prolong duration of postoperative analgesia. Inj. Dexmedetomidine (alpha(2)-Adrenoceptor agonist) and Inj. Nalbuphine (opioid agonist-antagonist) were studied as an adjuvant as to whether they increase the duration of post-operative analgesia. Secondary objectives of this study were to compare hemodynamic stability and side effects among Inj. Dexmedetomidine and Inj. Nalbuphine. METHODS A total of 60 patients with American Society of Anaesthesiologist physical Status I and II scheduled for elective perianal surgeries were randomly allocated into two equal groups in this randomized prospective comparative study. Group D received 0.5% hyperbaric bupivacaine 0.8 mL + 5 mcg dexmedetomidine and group N received 0.5% hyperbaric bupivacaine 0.8 mL + 0.6 mg nalbuphine. Onset and duration of sensory and motor blockade, and duration of analgesia were recorded. Post-operative analgesic consumption and side effects were studied for 24 hours. Statistical analysis was done by using descriptive and inferential statistics using Chi-square test and Student's t-test. RESULTS Demographic characteristics, duration of surgery, onset of sensory and motor block were comparable. Duration of analgesia was 320.26 +/- 89.52 min for dexmedetomidine (D) whereas it was 222.23 +/- 25.43 min for nalbuphine (N) with a P value of <0.05. No side effects were noted. CONCLUSION A dose of 5 mcg dexmedetomidine as an adjuvant seems to be optimal for providing postoperative analgesia with better hemodynamic stability.