Prospective randomized double-blind study to compare 0.125% Bupivacaine and 0.2% Ropivacaine infusion for adductor canal block after Total knee Arthroplasty for postoperative analgesia

INTRODUCTION:- A pragmatic multimodal approach for adequate pain management and for early ambulation after knee arthroplasty requires adductor canal blocks (ACB) or other regional techniques. Choosing the right dose of local anesthetic agent (LA) in ACB for pain management in knee arthroplasty is an important patient-centric decision. Inadequate volume or concentration may lead to inadequate analgesia, increased opioid consumption, and related morbidity and delayed discharge.Ropivacaine has lower lipid solubility than Bupivacaine which is responsible for lower penetration into myelinated motor fibers and thus less motor blockade. In view of the reduced toxic potential, ropivacaine has a definite edge over bupivacaine in regional anesthetic techniques requiring large volumes of local anesthetic.

AIMS AND OBJECTIVES:- Aim of the study is to compare the analgesic efficacy of 0.125 % bupivacaine and 0.2% ropivacaine  infusion for adductor canal block after total knee arthroplasty.

Primary object: -1) Analgesic efficacy (VAS score1-10) at different time interval; 10 is the worst pain. Secondary objective – Total consumption of rescue analgesia

STUDY PROCEDURE: - A prospective double blind randomized and comparative study will be conducted after approval from Institutional Ethical Committee and with informed written consent, thirty-six patients of American Society of Anesthesiologists (ASA) class I or class II of either sex, adult, undergoing elective Total Knee Arthoplasty surgeries done under spinal will be recruited.Patient will be given spinal anaesthesia. As per height & weight 0.5 % bupivacaine will be given. At the end of the surgery Adductor Canal Block will be given under ultrasound guidance by a trained qualified person by using needle catheter set. After confirmation of proper deposition of drug at the correct site, catheter will be introduced and fixed as per standard guide catheter will be introduced and fixed as per standard guidelines. Patient will be receiving study drug as per GROUP A AND GROUP B.**GROUP A: Receiving 0.125% of Bupivacaine Infusion @7ML/HR.****GROUP B: Receiving 0.2% of Ropivacaine Infusion @7ML/HR.**Allpatients will receive Inj Paracetamol 100 ml TDS as per surgical protocol.Patient will be monitored for vas score along with the quadriceps muscle strength at the interval of 0. 1,2,4,8,12 and 24 hrs postoperatively If VAS score is more than 5,infusion rate will be increased to 10 ml/hr, if still VAS score is high patient will receive Inj.Tramadol 1mg per Kg intravenously. Total doses of rescue analgesics and side effects like nausea , vomiting. bradycardia and hypotension will be noted.

Statistical analysis will be done by applying appropriate test. Both groups will be compared for VAS score, quadriceps muscle strength, total doses of rescue analgesics and side effects. With the time interval of Baseline, 1,2,4,6,8,12,24 HR of Intervals.