Study on the effect of nalbuphine as an adjuvant to 0.5% levobupivacaine in ultrasound guided supraclavicular Brachial Plexus Block

Brachial plexus block is the most widely used approach for upper limb surgeries as an alternative to and in combination with general anaesthesia to achieve ideal operating conditions by providing adequate muscle relaxation, maintaining intraoperative hemodynamic stability, and sympathetic block. This block also reduces postoperative pain and the requirement for rescue analgesia.A variety of approaches to brachial plexus have been described- inter scalene, supraclavicular, infraclavicular, and axillary. The supraclavicular block is the easiest to perform.The supraclavicular approach of the brachial plexus is the most common and effective block for most of upper limb surgeries. The supraclavicular approach blocks the brachial plexus at the level of distal trunks. The compact arrangement of structures at this site results in the rapid onset of dense and reliable blockade of the brachial plexus.The success of brachial plexus block relies on nerve localisation , needle placement and deposition of local anaesthesia solution at the right place by a single injection of local anaesthetic.The conventional blind technique relies on surface landmarks before needle insertion and elicitation of paresthesia while ultrasound guidance achieves excellent brachial plexus localization, accurate needle placement, and monitoring of drug spread in the appropriate tissue planes with painless performance. Ultrasound increases the success rate and reduces the injury to an adjacent structure. It also minimized the local anaesthethic volume, thereby reducing the incidence of their systemic toxicityUltrasound-guided supraclavicular brachial plexus block has improved the success rate of the block with excellent localization as well as an improved safety margin. By paraesthesia/ peripheral nerve stimulator technique, there is a risk of injury to surrounding structures, especially vascular structures and pleura.Local anaesthetics alone for supraclavicular brachial plexus block provide good operative conditions but have a shorter duration of postoperative analgesia. Hence, various adjuvants such as opioids,  clonidine, neostigmine, dexamethasone,  midazolam, and magnesium have been added to local anaesthetics in brachial plexus block to achieve quick, dense, and prolonged block. However, many are associated with side effects.Levobupivacaine, the S’enantiomer of bupivacaine, is a comparatively newer local anaesthetic agent acting on voltage dependent Na+ channels, introduced into clinical practice. It also possesses fewer cardiac and neural toxicities. Levobupivacaine is safe and effective for epidural and spinal anaesthesia and blockade of the brachial plexus.

Nalbuphine, derivative of 14 hydroxymorphine, is an agonist antagonist opioid acting on μ (mu) receptors as an antagonist and κ (kappa) receptors as an agonist with an analgesic potency equal to morphine, and its antagonistic potency is approximately ¼th of that of naloxone.  Unlike morphine, it exhibits a ceiling effect on respiratory depression. Nalbuphine can potentially maintain or even enhance μ opioid  based analgesia while simultaneously mitigating the μ’opioid side effects. .When nalbuphine given by intravenous route has  onset of action between 2 and 3 min  and a duration of action of 3–6 hrs with cardiovascular stability and minimal side effects in the dose of 0.2–0.4 mg/kg.  Nalbuphine can be used for pain management in children with burns and neoplastic or haematological diseases due to its safety profile.   Freedom from controlled drug act regulations and improved analgesia with nalbuphine render it more satisfactory for day care surgery than other commonly used opioids.Search for the suitable adjuvant with local anaesthetics involve use of an agent which provide a quick onset of action and prolong the duration of action and less requirement of analgesia .These attribute should be accompanied with little or no side effects with this in mind this study is being conducted with nalbuphine as an adjuvant to 0.5% levobupivacaine.Therefore, our current study is aimed to assess the clinical efficacy and safety of nalbuphine as an adjuvant to 0.5% levobupivacaine for the supraclavicular block using ultrasound-guided techniques for various forearm and hand surgery.