study comparing peri-articular injection of bupivacaine with and without epinephrine

Conditions: Osteoarthritis

Summary: this study involves research. the purpose of this research is to formally investigate the hemostatic efficacy of epinephrine to minimize blood loss after total joint arthroplasty. it is unclear if using intra-articular injections of epinephrine in total joint replacement is associated with a decrease in post-operative blood loss. the initial hypothesis is: the use of intra-articular injection of epinephrine is associated with decreased post-operative blood loss.

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.

Eligibility criteria:
inclusion criteria: * patients must be male or female of any race * ages 18-80yr * patients must be undergoing hip or knee arthroplasty * patients must be able to understand and be willing to cooperate with study procedures * patient must not take platelet inhibiting drugs for 10 days before surgery * able to provide written and verbal informed consent * preoperative hemoglobin above 12g/dl * osteoarthritis as the primary indication for knee arthroplasty, and either osteoarthritis or avascular necrosis as the indication for total hip arthroplasty exclusion criteria: * allergy or intolerance to the study materials or medications * surgical intervention during the past month for the treatment of the painful joint or its underlying etiology * history of any substance abuse or dependence within the last 6 months * patients who have received an investigational drug or device in the past 30 days * affected joint has undergone prior open surgery * patient received epoetin alfa 30 days before surgery * pre-operative autologous blood donation * use of platelet inhibiting drugs 10 days prior to surgery

Keywords: hip knee arthroplasty epinephrine hemostasis