Optimizing Local Anesthetic Concentration for Continuous Femoral Nerve Blocks
Overview
- Phase
- Phase 4
- Intervention
- 0.1% and 0.4% perineural ropivicaine
- Conditions
- Total Knee Arthroplasty
- Sponsor
- University of California, San Diego
- Enrollment
- 48
- Locations
- 1
- Primary Endpoint
- Quadriceps Femoris Muscle Strength Maximum Voluntary Isometric Contraction (MVIC)
- Status
- Completed
- Last Updated
- 6 years ago
Overview
Brief Summary
This is a randomized, observer-masked, controlled study. Subjects will be patients undergoing bilateral total knee arthroplasty (TKA). One side (left or right) will be randomized to one of two treatment groups: a postoperative ropivacaine concentration of 0.1% or 0.4%. The contralateral side will receive the other possible ropivacaine concentration of 0.1% or 0.4%. The basal rate and patient-controlled bolus volume will depend upon the treatment group, but the total dose of local anesthetic is the same for each. For the duration of the study, all patients will receive the current usual and customary analgesics for bilateral TKA patients. All patients will receive a ropivacaine perineural infusions initiated in the operating room and continued until at least the afternoon of postoperative day (POD) 2, as well as oral acetaminophen, a sustained-release oral opioid; and celecoxib. Rescue opioid and route of administration will be determined by pain severity using a Numeric Rating Scale of 0-10, with 0 equal to no pain and 10 being the worst imaginable pain.
Detailed Description
The investigators propose to test the null hypothesis that differing concentrations of ropivacaine (0.1% vs. 0.4%) at an equal total dose has no impact on quadriceps muscle strength during a continuous femoral nerve block following total knee arthroplasty (TKA). These results will help define the optimal concentration of local anesthetic used for continuous peripheral nerve blocks.
Investigators
Brian M. Ilfeld, MD, MS
Associate Professor, In Residence
University of California, San Diego
Eligibility Criteria
Inclusion Criteria
- •Primary, bilateral TKA
- •Age 18 years or older
- •Postoperative analgesic pain includes bilateral continuous femoral nerve blocks
Exclusion Criteria
- •Chronic, high-dose opioid use
- •History of opioid abuse
- •Any neuro-muscular deficit of either femoral nerves and/or quadriceps muscles
- •Pregnancy
- •Incarceration
Arms & Interventions
1) 0.1% Ropivicaine on Right Leg
Patients will be randomized ot 0.1% Ropivicaine infusion on the right leg and therefore 0.4% Ropivicain in fusion for the left leg for pain due to bilateral TKA. The outcome measures will be measured on both legs, starting with the right leg each time. The infusion will last for the two days following surgery, that the patient is staying in the hospital.
Intervention: 0.1% and 0.4% perineural ropivicaine
2) 0.4% Ropivicaine on Right Leg
Patients will be randomized ot 0.4% Ropivicaine infusion on the right leg and therefore 0.1% Ropivicain in fusion for the left leg for pain due to bilateral TKA. The outcome measures will be measured on both legs, starting with the right leg each time. The infusion will last for the two days following surgery, that the patient is staying in the hospital.
Intervention: 0.1% and 0.4% perineural ropivicaine
Outcomes
Primary Outcomes
Quadriceps Femoris Muscle Strength Maximum Voluntary Isometric Contraction (MVIC)
Time Frame: morning of postoperative day 2
A device was used called a dynamometer to measure the force during maximum voluntary isometric contraction. The dynamometer was placed on ipsilateral anterior tibia perpendicular to the tibial crest, just proximal to the medial malleolus. Subjects were asked to take 2 seconds to come to maximum effort contracting the quadriceps, maintain this effort for 5 seconds, and then relax.