Nalbuphine added to intrathecal morphine in total knee arthroplasty; effect on postoperative analgesic requirements and morphine related side effects

Introduction: Intrathecal morphine is widely used for postoperative pain control in major orthopaedic surgery. However, its use is associated with frequent side effects. Aim of the work: Aim of the work was to investigate the effects of intrathecal coadministration of nalbuphine with intrathecal morphine on morphine related side effects and postoperative analgesic requirements. Methods: In this study, the intrathecal addition of 1 mg nalbuphine hydrochloride to a combination of 3 ml hyperbaric bupivacaine 0.5% and 0.2 mg morphine sulfate was tried in patients undergoing total knee arthroplasty. Results: Patients who received intrathecal nalbuphine suffered significantly less than the control group from vomiting and pruritus meanwhile there was no effect on the postoperative analgesic requirements or the incidence of urinary retention. Intrathecal addition of nalbuphine to morphine decreased the opioid related side effects without affection of post operative analgesia Conclusions: The addition of nalbuphine to morphine intrathecally decreases the opioid related side effects without affection of postoperative analgesia. This combination can improve postoperative pain management in patients undergoing knee surgery under spinal anaesthesia.