Comparison of fentanyl and nalbuphine as adjuvants to intrathecal 0.5% bupivacaine in lower limb surgeries: A randomised double-blind prospective study.

Local anaesthetics used in spinal anaesthesia have a limited duration of action. To prolong postoperative analgesia, adjuvants, mainly opioids, are used. As µ agonist drugs have side effects, other receptor agonists are considered. Nalbuphine is a safe and effective kappa agonist adjuvant.