The Optimal Dosage of Ropivacaine for Arthroscopic Knee Surgery

Fast-track Surgery (FTS ) refers to the application of various proven effective methods in perioperative period to reduce stress and complications and accelerate the recovery of patients.Nowadays, FTS has been successfully applied in clinical practice."FTS" truly embodies the concept of "patient-centered" and the direction of medical development.

Lower limb joint damage (the meniscus, and patellar ligament, etc.) is the joint movement orthopedic common disease, often characterized by joint swelling, pain, sports relaxation instability, thigh muscle atrophy, most can't continue to pursue the original movement, even unbend and flexor limited activity, result in patients with walking difficulties, serious impact on the patient's quality of life.Practice has proved that minimally invasive surgery under arthroscopy is the best way to treat such injuries. According to literature reports, the average hospital stay after arthroscopy is 5~7 days, while successful application of FTS can shorten it to 2~3 days.

Anesthesia plays an important role in the process of FTS.Compared with general anesthesia, intra-spinal anesthesia can effectively reduce the incidence of postoperative complications in patients, such as ventilator-related lung injury, deep vein thrombosis, cardiovascular and cerebrovascular accidents, and acute renal failure.Ropivacaine is a long-acting amide local anesthetic. Compared with bupivacaine, it is more and more widely used in spinal anesthesia due to its advantages of lower degree of motor nerve block and weaker toxicity to central nervous system and cardiac.However, the optimal dosage of ropivacaine for arthroscopic surgery is still unclear. Conventional dosage makes patients unable to move 2-4h after surgery and unable to urinate autonomically. Therefore, this study aims to optimize the dosage of ropivacaine for spinal anesthesia and enable patients to recover motor function at an early stage.