Comparison of 3 Techniques for Ultrasound-guided Femoral Nerve Catheter Insertion
Condition: Total Knee Replacement Surgery
Study type: Interventional

Summary: 
      This is a randomized study which will compare three femoral nerve catheter insertion
      techniques. Subjects will be randomized into one of thee groups, Group 1: ultrasound guided
      femoral nerve catheter using a stimulation needle and stimulating catheter, .Group 2:
      ultrasound guided femoral nerve catheter using a stimulation needle, but non-stimulating
      catheter, or Group 3: ultrasound guided femoral nerve block without stimulation.
    

Detailed description: 
      This is a randomized study which will compare three femoral nerve catheter insertion
      techniques. Subjects will be randomized into one of thee groups, Group 1: ultrasound guided
      femoral nerve catheter using a stimulation needle and stimulating catheter, .Group 2:
      ultrasound guided femoral nerve catheter using a stimulation needle, but non-stimulating
      catheter, or Group 3: ultrasound guided femoral nerve block without stimulation.

        -  Pain Scores after surgery with be measured using the VAS (Visual Analogue Scale).
           Subjects will be asked to rate their pain on a scale of 1-10.

        -  Block Performance time is the time from starting the block (after prepping and draping)
           until catheter is placed.

        -  Opioid requirements will be measured as the total amount of opioids (converted to
           morphine sulfate equivalents) used both during surgery, and during the first 48 hours
           after surgery.

        -  Block failure rate will be calculated as the rate of cases that requires repeating the
           block after surgery.
    

Intervention name(s): ultrasound guidance alone; ultrasound guidance and needle stimulation; ultrasound guidance and catheter stimulation
Intervention type(s): Procedure; Procedure; Procedure
Intervention description(s): The Tuohy needle was inserted in out-plane approach. Needle placement was considered adequate when the tip was visualized beneath the fascia iliaca; the catheter was then introduced 5 cm beyond the needle tip. Electrical stimulation was not used.; For the ultrasound guidance and needle stimulation group, the Tuohy needle was positioned with the tip beneath the fascia iliaca under ultrasound guidance. The needle tip was then adjusted as necessary to obtain a quadriceps muscle response with a stimulating current ≤0.5 mA (2 Hz, pulse width 0.1 msec). Subsequently, the catheter was threaded 5 cm beyond the needle tip without additional electrical stimulation.; The Tuohy needle was positioned with the tip beneath the fascia iliaca under ultrasound guidance. The needle tip was then adjusted as necessary to obtain a quadriceps muscle response with a stimulating current ≤0.5 mA. At that point, the peripheral nerve stimulator was then disconnected from the stimulating needle and connected to the proximal end of the catheter. The catheter was then advanced 5 cm past the needle tip. If the motor response disappeared during catheter advancement, the catheter was withdrawn slightly until the response returned. Needle orientation and catheter advancement were adjusted as necessary to elicit quadriceps contractions via the catheter with a stimulating current ≤0.5 mA.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Investigator)
Primary purpose: Supportive Care
Keywords: TKA; total knee replacement