Conditions: Total Knee Arthroplasty
Keywords: Total Knee Arthroplasty. Sciatic nerve Blocks. Dexamethasone.
Allocation: RANDOMIZED | Intervention model: FACTORIAL
Enrollment: 43
Healthy volunteers: no

Brief summary:
Dexamethasone is a commonly used steroid. This medication has been used for many years by physicians for many different indications. Recent articles, multiple case reports, and experience at this institution have indicated that dexamethasone successfully prolongs the effective duration of local anesthetics for regional blocks. This can cause a significant reduction in postoperative pain and the decreased need for postoperative narcotics. Although other adjuncts can be used for prolonging nerve blocks, epinephrine causes local vasoconstriction which can cause ischemia and nerve damage in a large nerve such as the sciatic nerve.Dexamethasone will not cause this problem and yet could prolong the duration of a sciatic nerve block. Therefore, the goal of this study is to prospectively evaluate the effectiveness of dexamethasone, both locally through the nerve block and systemically via IV administration, in prolonging the effective duration of local anesthetics when used in sciatic nerve blocks.

Detailed description:

Arms:
arm 1: This is the control arm and subjects in Group A will have sciatic nerve block with 20ml of 0.2% Ropivacaine + 2ml IV of normal saline. arm 2: Subjects in Group B will have sciatic nerve block with 20ml of 0.2% Ropivacaine + 8mg Dexamethasone + 2ml IV of normal saline. arm 3: Subjects in Group C will have sciatic nerve block with 20ml of 0.2% Ropivacaine + 2ml IV (8mg)of Dexamethasone.

Interventions: intervention 1: Ropivacaine intervention 2: Dexamethasone intervention 3: Dexamethasone intervention 4: Normal Saline
Intervention descriptions: intervention 1: 20 ml of 0.2% ropivacaine injected locally as regional anesthesia given once. intervention 2: 8mg Dexamethasone injected locally along with ropivacaine for regional anesthesia given once. intervention 3: 2ml(8mg)Dexamethasone given once intravenously. intervention 4: 2ml of normal saline given once intravenously.

Protocol document: