Optimizing Catheter Insertion Technique for Ultrasound-guided Continuous Peripheral Nerve Blocks

Study Overview
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Brief Summary
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Continuous peripheral nerve blocks (CPNB; also known as perineural catheters) provide target-specific pain control for a variety of surgeries. There has been increasing interest in the use of ultrasound guidance for regional anesthesia, and many techniques using ultrasound alone for perineural catheter insertion have been described. Catheters may be placed at various points along the brachial plexus (for upper extremity procedures) or in proximity to the femoral and/or sciatic nerve (for lower extremity procedures). To date, the optimal ultrasound scanning technique, catheter insertion endpoint, catheter placement location per indication, for the majority of ultrasound-guided continuous peripheral nerve blocks remain unknown. This study will help provide important information related to optimal ultrasound scanning techniques and will help identify ways to improve the success rates, onset times, and analgesic effectiveness of these techniques for real patients undergoing surgical procedures.

Detailed Description
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Primary Aim: To determine if there is an optimal scanning technique for ultrasound-guided perineural catheter insertion that will result in the most accurate tip placement in proximity to the target nerve or plexus. Secondary Aim: To determine if there is an optimal location for ultrasound-guided perineural catheter insertion along a target nerve or plexus that will result in maximum local anesthetic infusion benefits.

Official Title
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Optimizing Catheter Insertion Technique for Ultrasound-guided Continuous Peripheral Nerve Blocks

Conditions
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Pain, Postoperative

Intervention / Treatment
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* Procedure: Proximal placement
* Procedure: Short axis ultrasound
* Procedure: Long axis
* Procedure: Distal placement


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: At least 18 years of age; Undergoing unilateral, upper (at or distal to the elbow) or lower (hip or distal) extremity orthopedic surgery, with moderate-to-severe postoperative pain expected; and Desiring a continuous perineural catheter for postoperative analgesia. Exclusion criteria: Patients who will have difficulty understanding the study protocol or caring for the infusion pump/catheter system; or Patients with any known contraindication to study medications, insulin-dependent diabetes mellitus, neuropathy of any etiology in the affected extremity; Patients with a contraindication to regional blockade (eg, clotting deficiency); Patients with any known acute or chronic hepatic or renal insufficiency or failure; Patients with any additional surgical site outside of the catheter-affected area (eg, iliac crest bone graft in addition to hand surgery); Patients with chronic opioid use (defined as daily use for more than 4 weeks prior to surgery) or active illicit substance abuse; Patient weighing < 40 kg; Pregnancy; Incarceration; or Inability to communicate with the investigators and hospital staff.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Imaging technique<br>In one substudy, subjects will be randomly assigned to either short axis or long axis target ultrasound imaging for perineural catheter insertion. The onset time of sensory anesthesia will be measured following local anesthetic bolus via the catheter. | Procedure: Short axis ultrasound<br>* Subjects assigned to this group will have the target nerve or plexus identified in short axis (cross-section) using ultrasound. Perineural catheter insertion will be performed in-plane. The onset time of sensory anesthesia will be measured following local anesthetic bolus via the catheter.<br>* Other names: Catheter placement technique;Procedure: Long axis<br>* Subjects assigned to this group will have the target nerve or plexus identified in long axis (longitudinal) using ultrasound. Perineural catheter insertion will be performed in-plane. The onset time of sensory anesthesia will be measured following local anesthetic bolus via the catheter.<br>* Other names: Catheter placement technique;|
| Active Comparator: Catheter location<br>In another substudy, subjects will be randomly assigned to receive their perineural catheters either proximally or distally along the same target nerve or plexus. | Procedure: Proximal placement<br>* Subjects assigned to this group will have their perineural catheter placed in a proximal position (higher up in the arm or leg) with ultrasound guidance. The onset time of sensory anesthesia will be measured following local anesthetic bolus via the catheter.<br>* Other names: Catheter placement technique;Procedure: Distal placement<br>* Subjects assigned to this group will have their perineural catheter placed in a distal position (further down in the arm or leg) with ultrasound guidance. The onset time of sensory anesthesia will be measured following local anesthetic bolus via the catheter.<br>* Other names: Catheter placement technique;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Onset time of sensory anesthesia | The primary outcome will be the onset time of sensory anesthesia in the target nerve distribution following injection of a local anesthetic bolus via the perineural catheter. | 30 minutes | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Time for placement | A secondary outcome measure will be the time required to insert the perineural catheter using the technique or location assigned. | 30 minutes | 
| Postoperative pain | A secondary outcome will be the surgical pain experienced by subjects as assessed by a 0-10 scale (0=no pain; 10=worst pain imaginable) and amount of opioid medications consumed. | 1 day | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Peripheral Nerve Block, Perineural Catheter, Orthopedic Surgery, Ultrasound