The Effects of Dexamethasone on the Duration of Sciatic Nerve Blocks

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.

Study Overview

• Status: Terminated
• Conditions: Total Knee Arthroplasty
• Intervention / Treatment: Drug: Ropivacaine; Drug: Normal Saline; Drug: Dexamethasone; Drug: Dexamethasone

• Study Type: Interventional
• Enrollment (Actual): 43
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • Loma Linda, California, United States, 92354
      • Loma Linda University Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 80 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Age 18-80 yrs, male or female subjects.
• Subjects must be scheduled to undergo total knee arthroplasty under general anesthesia with consent for a femoral and sciatic nerve block post operatively for pain control.
• American Society of Anesthesiology Class 1,2,3,or 4.
• Capable of speaking and understanding English sufficiently to provide written informed consent and able to respond when asked.
• Weight > or equal to 60kg.

Exclusion Criteria:

• Any allergies or hypersensitivity to ropivacaine or dexamethasone.
• Subject is on chronic steroids preoperatively for any reason.
• History of chronic pain syndrome (i.e. CPRS, Lumbar radiculopathy).
• History of documented or stated nerve damage or neuropathy to the surgical lower extremity.
• Contraindication to placement of sciatic nerve block.
• Sciatic block placement failure.
• Subject mistakenly receives steroids intraoperatively.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Factorial Assignment
• Masking: Triple

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Group A; 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.	Drug: Ropivacaine; 20 ml of 0.2% ropivacaine injected locally as regional anesthesia given once.; Drug: Normal Saline; 2ml of normal saline given once intravenously.
Experimental: Group B; Subjects in Group B will have sciatic nerve block with 20ml of 0.2% Ropivacaine + 8mg Dexamethasone + 2ml IV of normal saline.	Drug: Ropivacaine; 20 ml of 0.2% ropivacaine injected locally as regional anesthesia given once.; Drug: Normal Saline; 2ml of normal saline given once intravenously.; Drug: Dexamethasone; 8mg Dexamethasone injected locally along with ropivacaine for regional anesthesia given once.; Drug: Dexamethasone; 2ml(8mg)Dexamethasone given once intravenously.
Active Comparator: Group C; Subjects in Group C will have sciatic nerve block with 20ml of 0.2% Ropivacaine + 2ml IV (8mg)of Dexamethasone.	Drug: Ropivacaine; 20 ml of 0.2% ropivacaine injected locally as regional anesthesia given once.; Drug: Dexamethasone; 8mg Dexamethasone injected locally along with ropivacaine for regional anesthesia given once.; Drug: Dexamethasone; 2ml(8mg)Dexamethasone given once intravenously.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Duration of Sciatic Nerve Block	Intraoperative opioid requirement PACU opioid requirement Floor opioid usage Time of onset of motor block (or weakness) Time of onset of sensory block Return of motor function Return of sensation Pain scores	from the time the block was placed up to 24 hours

Collaborators and Investigators

• Sponsor: Loma Linda University
• Investigators: Principal Investigator: Charles Lee, MD, Loma Linda University

Study record dates

Study Major Dates

• Study Start: August 1, 2007
• Primary Completion (Actual): January 1, 2011
• Study Completion (Actual): May 1, 2011

Study Registration Dates

• First Submitted: February 4, 2008
• First Submitted That Met QC Criteria: February 4, 2008
• First Posted (Estimate): February 15, 2008

Study Record Updates

• Last Update Posted (Estimate): June 11, 2014
• Last Update Submitted That Met QC Criteria: June 10, 2014
• Last Verified: June 1, 2014

More Information

Terms related to this study

• Keywords: Total Knee Arthroplasty.; Sciatic nerve Blocks.; Dexamethasone.
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Central Nervous System Depressants; Autonomic Agents; Peripheral Nervous System Agents; Enzyme Inhibitors; Sensory System Agents; Anesthetics; Anti-Inflammatory Agents; Antineoplastic Agents; Antiemetics; Gastrointestinal Agents; Glucocorticoids; Hormones; Hormones, Hormone Substitutes, and Hormone Antagonists; Antineoplastic Agents, Hormonal; Protease Inhibitors; Anesthetics, Local; Dexamethasone; Dexamethasone acetate; BB 1101; Ropivacaine
• Other Study ID Numbers: 57164