Efficacy of Adrenaline in Periarticular Analgesic Injection on Postoperative Pain Control After Total Knee Arthroplasty

Multimodal anesthetic drug injection has been used extensively and the results of many studies suggest that postoperative pain can relief and improve the postoperative satisfaction of patients. Adrenaline is a combination of multimodal anesthetic cocktail to relieve pain. It is believed that Adrenaline causes vasoconstriction, reduces absorption of anesthetic drug into the system circulation. Currently, a comparative study on the effect of pain reduction of Adrenaline injection in the anesthetic cocktail is relatively low. There are different doses in each institution. In addition, the use of new anesthetic is Levobupivacaine that has more vasoconstrictive effect compare with traditional Bupivacaine. It also reduces the side effects of systemic and cardiotoxic effect. Therefore, the investigators think that It may not be necessary to mix Adrenaline in the multimodal anesthetic drug. Levobupivacaine already to avoid the potential side effects of Adrenaline.