Comparison between 0.25 percent of Bupivacaine and 0.25 percent of Ropivacaine with Dexamethasone in ultrasound guided femoral nerve block for post operative analgesia after total knee arthroplasty

Total knee replacement (TKR) is associated with significant postoperative pain. This postoperative pain is difficult to treat with oral analgesics, resulting in adverse endocrine, metabolic, and inflammatory responses . Single-injection femoral nerve block (FNB) significantly improves postoperative analgesia compared with systemic opioid therapy at least during the first 24 hours after TKR or ACL reconstruction  although some studies show a limited benefit of single-injection FNB as an analgesic technique during TKR or ACL reconstruction. The pain after TKA is severe and does not fade noticeably for 48–72 h after the surgery. Effective pain control allows for earlier ambulation and initiation of physiotherapy, which hastens recovery, A reduces the length of stay in the hospital, and lowers the risk of postoperative complications, such as thromboembolic dis- ease or nosocomial infections. Bupivacaine is the standard, long-acting local anaesthetic used in regional anaesthetic practice together with ropivacaine, a N-propyl homologue of bupivacaine and a pure S(-) enantiomer . Ropivacaine has shown a reduced potential for central nervous system toxicity and cardiotoxicity in laboratory experiments and in healthy volunteers . Total knee replacement (TKR) is associated with significant postoperative pain. This postoperative pain is difficult to treat with oral analgesics, resulting in adverse endocrine, metabolic, and inflammatory responses . Single-injection femoral nerve block (FNB) significantly improves postoperative analgesia compared with systemic opioid therapy at least during the first 24 hours after TKR or ACL reconstruction  although some studies show a limited benefit of single-injection FNB as an analgesic technique during TKR or ACL reconstruction.  The pain after TKA is severe and does not fade noticeably for 48–72 h after the surgery. Effective pain control allows for earlier ambulation and initiation of physiotherapy, which hastens recovery, A reduces the length of stay in the hospital, and lowers the risk of postoperative complications, such as thromboembolic disease or nosocomial infections. Bupivacaine is the standard, long-acting local anaesthetic used in regional anaesthetic practice together with ropivacaine, a N-propyl homologue of bupivacaine and a pure S(-) enantiomer . Ropivacaine has shown a reduced potential for central nervous system toxicity and cardiotoxicity in laboratory experiments and in healthy volunteers. Dexamethasone added to local anaesthetics (LAs) appears to prolong single-injection nerve block. The analgesic effects of spinal and systemic corticosteroids combined with LAs have proven to be effective in humans, whereas dexamethasone microspheres have increased block duration .

The purpose of the study is to compare difference in post operative analgesic duration, amount of sedation and systemic side effects in 0.25%bupivacaine and 4mg dexamethasone with 0.25% ropivacaine and adjuvant 4mg dexamethasone using femoral nerve block as a post operative analgesia in TKR