Catheter-based Peripheral Regional Anesthesia After Orthopedic Surgery to the Foot or Ankle
Condition: Postoperative Pain
MeSH terms: Pain, Postoperative
Study type: Interventional
Phase: Phase 4

Summary: 
      BACKGROUND

      Orthopedic surgery can be severely painful, and peripheral regional anesthesia is highly
      recommended as part of the perioperative pain treatment. Whether catheter-based techniques
      are better than single injection techniques are debatable. Furthermore, in catheter-based
      techniques, whether a low-dose automated, periodic infusion can produce similar analgesic
      effectiveness compared to a conventional, high dose, continuous infusion has never been
      explored.

      AIM

      Comparison of the analgesic effectiveness of a low-dose automated, periodic infusion, a
      conventional continuous infusion and patient-controlled boluses only in catheter-based nerve
      blocks for patients undergoing orthopedic surgery to the foot or ankle.
    

Detailed description: 
      BACKGROUND

      Orthopedic surgery has been reported to be moderate to severely painful in approximately 50 %
      of patients.

      Peripheral regional anesthesia (PRA) using single injection nerve blocks is highly
      recommended as part of a multimodal, perioperative, analgesic treatment. Patients who are
      expected to have postoperative, severe pain exceeding the duration of a single injection
      nerve block may benefit from a catheter-based nerve block (CBNB) using either a continuous
      infusion (CI) or intermittent infusions of local anesthetics (LA). Intermittent boluses can
      be either patient-controlled or prescribed in combination with a continuous infusion or as
      prespecified intermittent boluses. Whether a CBNB treatment is superior to a single injection
      nerve block after orthopedic surgery remains unanswered.

      There are several challenges when using a CBNB treatment: The dosing or delivery method may
      be either insufficient and thus not pain relieving or too powerful resulting in dense motor
      block and limb anesthesia which may compromise safety and rehabilitation. The peripheral
      nerve block catheter may also displace and therefore deposit LA too far from the targeted
      nerve(s) to produce an effective nerve block.

      Previous studies suggest that an automated periodic infusion (API) regimen is superior to CI.
      It seems that an API produces better pain control, a lower analgesic consumption over time
      and less motor inhibition. This is well-described for epidural catheters for laboring women,
      but evidence is also apparent in PRA. Adding a PCA bolus option to a catheter-based nerve
      block treatment may even out the difference in pain scores between API and CI. However, it
      seems that API groups require less LA via PCA function. Reducing LA consumption is of great
      importance for ambulatory patients whose LA reservoir is limited, but also for all other
      orthopedic patients whose motor block should be minimized in order to optimize
      rehabilitation.

      OBJECTIVES

      To investigate whether a low-dose API with patient-controlled bolus option can produce a
      similar analgesic effect compared to a conventional, high dose, CI with patient-controlled
      bolus option in catheter-based peripheral nerve blocks for patients undergoing orthopedic
      surgery to the foot or ankle. Analgesic effectiveness will be compared with a group only
      given the patient-controlled bolus option.

      HYPOTHESIS

      Low dose API with supplemental patient-controlled bolus option will provide pain-relieving
      therapy not inferior to a conventional CI with supplemental patient-controlled bolus option.
      The intervention group receiving patient-controlled boluses only will experience more pain
      breakthrough.
    

Intervention name(s): Ropivacaine 0.2%
Intervention type(s): Drug
Intervention description(s): Perineural infusion of Ropivacaine 0.2% using a peripheral nerve block catheter and a portable infusion pump.
Other intervention name(s): Naropin 0.2%
Intervention MeSH terms: Ropivacaine
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: 3 arms (API, CI and PCA only)
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Peripheral regional anesthesia