A Comparison of Postoperative Analgesic Nerve Block Ropivacaine Concentrations
Condition: Total Hip Arthroplasty; Postoperative Pain
MeSH terms: Pain, Postoperative
Study type: Interventional

Summary: 
      Peripheral nerve blocks are the standard of care for pain management after hip replacement
      surgery at UPMC Shadyside. This prospective, randomized study is intended to assess the
      effect of 0.1 versus 0.2% ropivacaine in lumbar plexus nerve catheter infusions after total
      hip arthroplasty. Ropivacaine peripheral nerve block infusions have been utilized as the
      standard of care at UPMC Shadyside for many years. Ropivacaine, a less potent left-isomer of
      bupivacaine, is often used in place of bupivacaine due to less motor blockade and less severe
      cardiovascular and central nervous system potential toxicity.

      The primary goal of this study to examine the effect of a low concentration infusion of
      ropivacaine (0.1%) on postoperative analgesia (evaluated by opioid consumption after 36
      hours) compared with the standard accepted concentration of 0.2% ropivacaine in lumbar plexus
      catheters after primary total hip arthroplasty. Secondary goals are to examine motor
      function, VAS scores and patient satisfaction with pain control in low concentration 0.1%
      ropivacaine compared with 0.2% ropivacaine lumbar plexus infusions upto 36 hours after
      primary total hip arthroplasty.
    

Detailed description: 
      Lumbar plexus catheters are the standard of care for postoperative pain management following
      total hip arthroplasty (THA) at UPMC Shadyside. The safety and efficacy of this technique has
      been demonstrated by multiple studies. Ropivacaine 0.2% was used for many years at UPMC
      Shadyside and throughout the UPMC system and this concentration of ropivacaine is the
      standard local anesthetic utilized by multiple other studies. However, this concentration of
      ropivacaine was later decreased to 0.1% in our institution in order to decrease patient's
      motor weakness and promote postoperative physical therapy. Patients were clinically observed
      to continue to have adequate postoperative analgesia while demonstrating improved motor
      function. A randomized, double blinded clinical trial has never compared 0.1 and 0.2%
      ropivacaine.
    

Intervention name(s): 0.1% or 0.2% ropivacaine nerve blocks
Intervention type(s): Drug
Intervention description(s): Either 0.1% or 0.2% ropivacaine will be infused at 7 mL/hr through lumbar plexus nerve block catheter based upon randomization, and can then receive a 6 ml bolus of either 0.1% or 0.2% ropivacaine. Additional pain relief will be available by nurse administered boluses of additional local anesthetic (from their randomized infusion) with a maximum dose of an extra 3 ml per bolus and limited to one bolus per hour. This bolus of their randomized local anesthetic will remain available until the nerve catheters are removed. Nerve block infusion rates may be increased to 9 ml/h for patients with increased pain without increased motor blockade as determined by the acute interventional perioperative pain service (AIPPS) or decreased to 5 ml/h for patients with increased motor blockade or weakness from the peripheral nerve block as determined by the AIPPS .All continuous lumbar plexus catheters will be removed on post operative day (POD) 2.
Other intervention name(s): Naropin (ropivacaine hcl)
Intervention MeSH terms: Ropivacaine
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Peripheral nerve blocks; Ropivacaine concentrations in lumbar plexus catheters; Postoperative pain; Total hip replacement