Clinical Trial: Effect of Mode of Femoral Nerve Analgesia on Quadriceps Muscle Strength

Study Status: Completed
Recruit Status: Unknown status
Study Type: Interventional

Official Title: Effect of Continuous Femoral Analgesia on Quadriceps Muscle Strength-0.2% Ropivacaine Continuous Infusion Versus Patient Controlled Femoral Analgesia

Brief Summary: Quadriceps muscle strength is an important determinant of quality of recovery in elderly patients after total knee arthroplasty. We try to compare the quadriceps muscle strength change between 0.2 % ropivacaine continuous fixed femoral infusion and patient controlled femoral analgesia group.

Detailed Summary: Continuous femoral nerve analgesia technique is relatively safe, can be easily trained, and reduces significantly intravenous opioid consumption. These favorable features make it standard treatment option for postoperative knee pain. However, direct perineural local anesthetic effect is not only confined into pain fiber, but, the other sensory and motor nerve fibers. Therefore, unwanted motor weakness is accompanied. Quadriceps muscle strength, which is important determinant of physical function after knee arthroplasty, can be influenced in continuous femoral nerve block. Various local anesthetic infusion techniques have been suggested to minimize the change of quadriceps muscle strength. Decreasing local anesthetic concentrations affect not only degree of muscle weakness, but also reduces the quality of pain control. Different anatomic location of catheter tip, considering motor fiber in posterior part of femoral nerve, could not reduce motor weakness. In a study with continuous popliteal-sciatic nerve blocks after hallux valgus repair, repeated bolus administration seems to be more effective method for pain control without concurrent motor impairment. However, another study with continuous femoral nerve block in healthy volunteers, hourly repeated bolus dose of 5 ml of 0.1% ropivacaine failed to spare motor block. Previously, our institution standard technique is fixed continuous infusion of 0.2% ropivacaine and concomitant intravenous patient controlled fentanyl. Because physical therapy of our institution, usually starts with the 2nd day of operation, so, we assume that continuous fixed infusion may result in more drug accumulation near nerve fiber. So, patient controlled mode of femoral analgesia could be better choice for initiation of physical therapy. At the same time, comparison between patient controlled analgesia and continuous infusion is not fully elucidated until recently. Therefore, in this study, we try to compare quadriceps muscle strength change be
Sponsor: Seoul National University Hospital

Current Primary Outcome: Change of quadriceps muscle strength [ Time Frame: Baseline, Postoperative 2nd day ]

Original Primary Outcome:

• quadriceps muscle strength [ Time Frame: preoperative period ]
  maximum voluntary isometric contraction of quadriceps femoris with hand held manometry
• quadriceps muscle strength [ Time Frame: postoperative 1 day ]
  maximum voluntary isometric contraction of quadriceps femoris with hand held manometry
• quadriceps muscle strength [ Time Frame: postoperative 2 day ]
  maximum voluntary isometric contraction of quadriceps femoris with hand held manometry

Current Secondary Outcome:

• sensory changes in femoral nerve distribution [ Time Frame: postoperative 2 day ]
  tolerance to transcutaneous electrical stimulation
• pain scores [ Time Frame: postoperative 1 day ]
  verbal numeric pain scale (0-100) resting/dynamic
• pain scores [ Time Frame: postoperative 2 day ]
  verbal numeric pain scale (0-100) resting/dynamic
• intravenous fentanyl consumption [ Time Frame: postoperative 2 day ]
  cumulative fentanyl consumption on postoperative 2 day

Original Secondary Outcome: Same as current

Information By: Seoul National University Hospital

Dates:
Date Received: October 28, 2013
Date Started: February 2014
Date Completion: July 2015
Last Updated: July 29, 2014
Last Verified: July 2014