Ultrasound Guided Genicular Nerve Block for Knee Arthroscopy. Comparing using Bupivacaine Alone Versus Bupivacaine and Dexmedetomidine for Acute Post Operative Pain Management: A Comparative Controlled Study

Abstract Background: During knee artroscopy, mechanical and ther-mal trauma can cause muscle ischemia and damage to nerves innervating the knee joint. Therefore, it is often characterized by severe and diffuse pain in the postoperative period, So ad-equate postoperative analgesia is essential to allow early mo-bilization, reducing the incidence of postoperative respiratory complications, and decrease the risk of chronic pain syndrome. Aim of Study: To investigate the effectiveness of a mix-ture of dexmedetomidine and bupivacaine versus bupivacaine alone in genicular nerve block for postoperative analgesia in knee surgery. Patients and Methods: The study was conducted at ortho-pedic operation Theater at Souad Kafafi University Hospital, Misr University of science and Technology (MUST). 70 Pa-tients aged above 21 years, scheduled for knee arthroscopy sur-gery, 35 patients in each group equally. Results: Intra operative Fentanyl Consumption (μg/kg) there was significantly lower in Bupivacaine& Dexmedeto-midine group (P<0.003). Postoperative pain (VAS-10) among both study groups there weren’t significantly lower in Bupiv-acaine & Dexmedetomidine group throughout follow up time points, but the differences were statistically significant at hour 8 and 12. post-operative morphine consumption there was sig-nificantly lower in Bupivacaine & Dexmedetomidine group. Time to first postoperative dose was significantly longer in Bupivacaine & Dexmedetomidine group. Post-operative com-plications related to morphine consumption (nausea, vomiting and pruritus) were less frequent in Bupivacaine & Dexmedeto-midine group, but the differences were statistically significant only in nausea.
Conclusion: The addition of dexmedetomidine to bupiv-acaine in US-guided genicular nerve block during knee arthros-copy reduce both intra operative fentanyl consumption and post operative morphine consumption, significantly prolong time to first postoperative morphine dose and reduces post-operative Nausea, vomiting (PONV) and pruritis owing to lowering the total opioid consumption compared with bupivacaine alone.