Study Comparing Peri-articular Injection of Bupivacaine With and Without Epinephrine

Total hip and knee arthroplasties are associated with considerable blood loss, and can conservatively range from 480 ml to 1.39 liters. Current research has focused on the prevention of allogeneic blood transfusion with the pre-operative donation and use of epoetin alfa. While the pre-operative use of epoetin alpha is associated with a substantial decrease in the rate of transfusion, there still warrants investigation into the conservation of blood volume after total joint arthroplasty. Although epinephrine has been in use as a local hemostatic agent, the use of epinephrine injection in joint replacement is limited. The mechanism of hemostasis by epinephrine is physiologic vasoconstriction. Despite the plethora of hemostatic agents available on the market today, the rationale for the use of epinephrine in this study is the medication's mechanism of action and safety. Epinephrine's alpha receptor-mediated vasoconstriction is must be balanced with vasodilation caused by its stimulation of beta-2 receptors. The relative concentration of epinephrine determines the degree of vasoconstriction versus dilation. A better understanding of the hemostatic properties and potential of intra-articular epinephrine injection will help minimize post-operative blood loss. In turn, this may decrease the number of units transfused, increase the patient's progression in physical therapy, and shorten the hospital length of stay. The goal of this prospective, randomized, double-blinded controlled clinical trial is to compare the post-operative blood loss and transfusion rate following total joint arthroplasty with intra-articular injection of marcaine and epinephrine versus the post-operative blood loss and transfusion rate following total joint arthroplasty with intra-articular injection of marcaine alone.