Nalbuphine versus Dexmedetomidine as an Analgesic Additive to Lidocaine in Intravenous Regional Anesthesia IVRA

Intravenous Regional Anesthesia (IVRA) is easy to administer and reliable. But delayed onset and lack of postoperative analgesia are the major limitations. Accordingly, many additives have been tried. Dexmedetomidine is a highly selective α-2 adrenoceptor agonist. Addition of dexmedetomidine to lignocaine is effective in decreasing the anesthetic requirements and prolonging the analgesic duration. On the other hand, many theories explain that opioids may exert their peripheral action through peripheral opioid receptors. The aim of the study was to compare the analgesic efficacy of nalbuphine and dexmedetomidine when used separately as adjuvants to lidocaine during IVRA with the effect of lidocaine alone. Sixty adult patients, who were scheduled for surgery of the hand or the forearm under intravenous regional anesthesia, were included in this study. The patients were randomly allocated into three equal groups. The syringes in all groups contained 3 mg/kg of lidocaine 0.5% diluted in 40 ml isotonic saline. Group C: Control group. Group D: Dexmedetomidine group, 1 mic/kg dexmedetomidine diluted was added. Group N: Nalbuphine group, 20 mg nalbuphine was added. Sensory onset time (min) as well as motor block onset time (min) were significantly shorter in Groups N (2.0 ± 1.7) (3.8 ± 2.1) respectively, and D (2.2 ± 1.8) (4.6 ± 2.2) respectively compared to Group C (3.6 ± 1.6) (7.1 ± 1.4) (P < 0.05), with no significant differences between nalbuphine and dexmedetomidine groups. Sensory and motor block recovery times (min) were significantly longer in Groups N (9.6 ± 0.7) (10.3 ± 1.2) and D (8.1 ± 1.1) (9.1 ± 2.1) when compared to Group C (3.4 ± 2.1) (3.7 ± 3.1) (P < 0.05), without significant differences between nalbuphine and dexmedetomidine. Ramsay sedation score was significantly higher (RSS = 2) in 14 patients (70%) in Group D compared to Groups C and N during the first 30 min after the release of tourniquet.