The purpose of this study is to further investigate the efficacy of adductor canal nerve blocks for pain management after total knee replacement. Specifically we are studying adductor canal nerve blocks in conjunction with epidural anesthesia, which is a combination that has not been extensively researched before. Our question is whether combining these modalities will enhance patient satisfaction after surgery and accelerate patients' readiness to discharge.
Knee replacement surgery has become increasingly more common in the United States with hundreds of thousands of surgeries performed yearly across the country. Despite that, there is no consensus "standard of care" for optimum pain control regimen after surgery. Pain management after TKA ranges from local tissue injections and patient controlled anesthesia to regional nerve blocks to neuraxial anesthesia. Although regional anesthesia has become more common and widespread, there are wide variations depending on practice setting (academic versus private), equipment available (adductor nerve blocks require ultrasound guidance), level of training of the anesthesiologists and patient selection, among other factors. Another part of the reason for the wide variations in practice is the lack of literature demonstrating clear effectiveness or superiority of one technique over another. To date adductor canal nerve blocks have been mainly studied in comparison with femoral nerve blocks in terms of their efficacy in controlling pain and their ability to preserve motor function. Adductor canal nerve blocks have been shown in the literature to be an effective method for postoperative pain control in total knee replacement surgery. One of the unique benefits of this particular technique is that the adductor canal nerve block is primarily a sensory block, thereby controlling pain without impairing motor strength. This is useful for total knee replacement surgery as pain is controlled while quadriceps muscle strength is preserved. With well functioning muscles patients are able to fully participate in physical therapy with less strength impairment and reduced risk of falling. It is our aim to investigate one multimodal approach that combines the strengths of two proven pain management techniques and thereby improve overall postoperative pain control and patient satisfaction. Our hope is to establish a protocol that is safe and effective for patient care.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
ACNB catheter will be placed by anesthesia residents under the supervision of board-certified anesthesiologists familiar with regional anesthesia techniques, who are part of the anesthesia pain service. They will be performed at the bedside, aseptically, with the patient's vital signs monitored throughout the procedure. 1% lidocaine will be infiltrated in the skin and subcutaneous tissues overlying the adductor canal as visualized on ultrasound. Via a 17 gauge touhy needle a closed tip non-stimulating, epidural catheter will be placed after 1% lidocaine is used to hydrodissect the space lateral to the superficial femoral artery within the adductor canal. The catheter will be secured to the skin. All catheters will be connected to infusion pumps with opaque plastic bags covering the pumps. The functional ACNB pumps will run 8cc/h.
Patients randomized to the sham catheter will have a chlorhexidine prep of the skin and ultrasound examination of the adductor canal on postoperative day #1. To minimize patient risk, a wooden applicator will be used to apply 10 seconds of pressure to the leg followed by catheter securing to the skin with the same tegaderm and paper tape dressing used on functional catheters. All catheters will be connected to infusion pumps with opaque plastic bags covering the pumps. The sham catheter pumps will not be turned on.
University of Chicago Medicine
Chicago, Illinois, United States
Morphine Equivalents
Time frame: 12 hours postoperatively and 20 hours after placement of catheter
Visual Analog Score for Pain
The visual analog scale (VAS) is a pain rating scale. Scores are based on self-reported measures of symptoms that are recorded with a single mark placed at one point along the length of a line that represents a continuum between the two ends of the scale-"no pain" on the left end of the scale (equal to a score of 0) and the "worst pain" on the right end of the scale (equal to a score of 100).
Time frame: 12 hours postoperatively and 20 hours after placement of catheter
Physical Therapy Ambulation Distance
Time frame: Daily on postoperative days one and two
Number of Hospital Days Until Discharge Criteria Are Met
Time frame: within first 3 days (plus or minus 3 days) after surgery
Number of Participants With Bleeding Complications at Adductor Canal Nerve Block Catheter Site
Time frame: within first 3 days (plus or minus 3 days) after surgery
Number of Participants With Adverse Events Related to Adductor Canal Nerve Block Catheter
Time frame: within first 3 days (plus or minus 3 days) after surgery
Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC)
The Western Ontario and McMaster Universities Arthritis Index (WOMAC) is widely used in the evaluation of Hip and Knee Osteoarthritis. It is a self administered questionnaire consisting of 24 items divided into 3 subscales: pain (5 items), stiffness (2 items), and physical function (17 items). The subscale scores can vary, with pain ranging from 0 to 20 points; stiffness, 0 to 8 points; and physical function, 0 to 68 points. Higher scores represent worse pain, stiffness, and functional limitations. A sum of the scores for all three subscales yields a total WOMAC score.
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Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
165
In the functioning continuous adductor canal block, 0.125% bupivacaine will be infused at a rate of 8cc/hr.
Time frame: 3 and 6 weeks
Range of Motion
Knee range of motion (ROM) was measured (in degrees) during physical therapy.
Time frame: postoperative day 1 and 2
Range of Motion at 3 and 6 Week Follow up
Time frame: 3 and 6 weeks