Combination of Peripheral Nerve Block and DepoDur in Total Knee Joint Replacement
Condition: Arthroplasty, Replacement, Knee
Intervention: Depodur; sciatic nerve block
Intervention description: 7.5 mg Depodur via the epidural catheter; The sciatic nerve will be identified at the subgluteal level with ultrasound. A point 3 cm lateral and 4 cm caudad will be marked. Patients will be placed in the lateral position. A 18 G Tuohy needle will be inserted at a 45° angle until a peroneal or tibial twitch is obtained at 1.5 mA. Once the current can be reduced to obtain a twitch less than 0.5 mA, a catheter will be inserted and placed perineurally. If placed preoperatively, the catheter will be flushed with normal saline or 5% dextrose and will not be dosed until after surgery. After the patient is in the PACU and the surgeons have verified the sciatic nerve function, the sciatic catheter will be dosed with 35 mL 0.25% ropivacaine.
Intervention MeSH terms: Morphine
Phase: Phase 4
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Investigator)
Enrollment: 75.0
Sex: All
Minimum age: 18 Years
Maximum age: 70 Years
Healthy volunteers: No
Keywords: Knee Replacement, Total; Morphine

Summary:

      The investigators hypothesize that patients who receive a femoral catheter with low dose
      epidural Depodur will experience comparable or superior pain relief than those who receive
      both femoral and sciatic catheters. In addition, the investigators hypothesize that the one
      catheter will be less time consuming to place and facilitate early ambulation of the patient.
    

Eligibility criteria:

        Inclusion Criteria:

          -  Scheduled for total knee replacement or revision of total knee replacement

          -  Agree to have a regional technique including neuraxial analgesia for post-operative
             analgesia

          -  Be 18 to 70 years old

          -  Classified as ASA score I-III

        Exclusion Criteria:

          -  Allergic to morphine

          -  Allergic to local anesthetics

          -  Been on opioids for more than 4 weeks

          -  Not willing to be randomized

          -  On anticoagulation medications that prevent placement of epidural

          -  Sensitive to effects of neuraxial opioids

          -  BMI>35

          -  Severe COPD

          -  Obstructive sleep apnea (OSA, see below). Each patient will be asked the questions
             below to determine their risk for OSA (STOP questionnaire). Patients who answer yes to
             3 or more of the major criteria of the STOP questionnaire and have one of the minor
             criteria will be excluded from the study

        STOP Questionnaire for OSA

        Major Criteria:

        S- Do you snore loudly (louder than talking or loud enough to be heard through closed
        doors)?

        T-"Do you often feel tired, fatigued, or sleepy during daytime?

        O-"Has anyone observed you stop breathing during your sleep?

        P-"Do you have or are you being treated for high blood pressure?

        Minor Criteria:

          -  BMI>35

          -  Age>50 yrs

          -  Neck Circumference>40 cm

          -  Male gender