Optimizing Local Anesthetic Concentration for Continuous Popliteal-Sciatic Nerve Blocks

NCT01898689 | Completed Phase 4 Results

• 1 other identifier: Baxter Popliteal Volunteer
• Study Type: interventional
• Target: 24
• Locations: 1 country
• Sites: 1

Brief Summary

A continuous peripheral nerve block-also termed "perineural local anesthetic infusion"-involves the insertion of a tiny tube (a "catheter") through the skin and adjacent to a peripheral nerve, followed by local anesthetic (numbing medicine) administration via the catheter, providing pain control following surgery. Continuous peripheral nerve blocks may be provided in the hospital setting, but the use of lightweight, portable pumps permits infusion at home as well. However, it remains unknown if the concentration of the local anesthetic influences the block effects; or, is it rather simply the total dose of medication that is important. If it is the latter, then the concentration of local anesthetic could be increased, allowing a decreased basal infusion rate, which would allow patients at home to receive twice the duration of potent pain control since their infusion pump local anesthetic reservoir would last twice as long as current practice. In addition, if one concentration/dose combination results in less muscle weakness, but with at least equivalent analgesia, then the risk of falling might be decreased as well. The investigators will test the hypothesis that providing ropivacaine at different concentrations and rates (0.1% at 8 mL/hour vs. 0.4% at 2 mL/hour)-but at an equivalent total basal (8 mg/hour)-produces comparable effects when used in a continuous popliteal-sciatic nerve block.

Conditions

Relatively Healthy Volunteers

Outcome Measures

Primary Outcomes (1)

• Maximum Tolerance to Transcutaneous Electrical Stimulation

  Electrocardiogram pads are placed on the lateral aspect of the plantar surface of the foot which is covered by the sciatic nerve distribution; and, the tolerance to cutaneous electrical current is obtained using a nerve stimulator. The current is increased from 0 mA until subjects detect the electrical current (up to a maximum of 80 mA), at which time the current is recorded and the nerve stimulator turned off.

  Hour 6

Secondary Outcomes (2)

• Maximum Tolerance to Transcutaneous Electrical Stimulation

  baseline, Hours 1-14 (except 6 which was the primary outcome) and Hour 22

• Percent of Maximum Voluntary Isometric Contraction Baseline (Quadriceps Femoris)

  baseline, Hours 1-14 and Hour 22

Study Arms (2)

RIGHT side Ropivacaine 0.1% and LEFT side Ropivacaine 0.4%

EXPERIMENTAL

Bilateral sciatic perineural catheters were inserted and ropivacaine administered as a basal infusion concurrently. For the right catheter, ropivacaine 0.1% was infused at 8 mL/h basal for 6 hours. For the left catheter, ropivacaine 0.4% was infused at 2 mL/h for 6 hours.

Drug: Ropivacaine 0.1%; Drug: Ropivacaine 0.4%

RIGHT side Ropivacaine 0.4% and LEFT side Ropivacaine 0.1%

ACTIVE COMPARATOR

Bilateral sciatic perineural catheters were inserted and ropivacaine administered as a basal infusion concurrently. For the right catheter, ropivacaine 0.4% was infused at 8 mL/h basal for 6 hours. For the left catheter, ropivacaine 0.1% was infused at 2 mL/h for 6 hours.

Drug: Ropivacaine 0.1%; Drug: Ropivacaine 0.4%

Interventions

Ropivacaine 0.1% DRUG

A sciatic catheter was inserted and ropivacaine 0.1% was administered as a basal infusion for 6 hours.

Also known as: continuous peripheral nerve block

RIGHT side Ropivacaine 0.1% and LEFT side Ropivacaine 0.4%; RIGHT side Ropivacaine 0.4% and LEFT side Ropivacaine 0.1%

Ropivacaine 0.4% DRUG

A sciatic catheter was inserted and ropivacaine 0.4% was administered as a basal infusion for 6 hours.

Also known as: continuous peripheral nerve block

RIGHT side Ropivacaine 0.1% and LEFT side Ropivacaine 0.4%; RIGHT side Ropivacaine 0.4% and LEFT side Ropivacaine 0.1%

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• age ≥ 18 years
• willing to have bilateral femoral perineural catheters placed with a subsequent ropivacaine infusion and motor/sensory testing for 6 hours, requiring an overnight stay in the UCSD GCRC/CTRI to allow dissipation of local anesthetic infusion effects by the following morning

You may not qualify if:

• current daily analgesic use
• opioid use within the previous 4 weeks
• any neuro-muscular deficit of either femoral nerves and/or quadriceps muscles
• morbid obesity \[weight \> 35 kg/m2\]
• pregnancy (as determined by a urine pregnancy test prior to any study interventions)
• incarceration

Sponsors & Collaborators

• University of California, San Diego: lead
• Baxter Healthcare Corporation: collaborator

Study Sites (1)

University California San Diego

San Diego, California, 92103, United States

Location

Related Publications (1)

• Madison SJ, Monahan AM, Agarwal RR, Furnish TJ, Mascha EJ, Xu Z, Donohue MC, Morgan AC, Ilfeld BM. A randomized, triple-masked, active-controlled investigation of the relative effects of dose, concentration, and infusion rate for continuous popliteal-sciatic nerve blocks in volunteers. Br J Anaesth. 2015 Jan;114(1):121-9. doi: 10.1093/bja/aeu333. Epub 2014 Sep 23.

  PMID: 25248648 RESULT

Results Point of Contact

• Title: Dr. Brian Ilfeld
• Organization: UC San Diego

bilfeld@ucsd.edu

(858) 444-5949

Study Officials

• Brian M Ilfeld, MD, MS

  University California San Diego

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: phase 4
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: The only individual aware of the treatment group assignments is the investigational pharmacist who has no interaction with the study subjects. Treatment group assignments were released by the investigational pharmacy only after completion of data collection.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor of Anesthesiology, In Residence

Model Details: This is a split-body study in which each study subject receives both treatments: one on each side of the body. Which treatment is applied to which side of the body is randomized (and masked).

Study Record Dates

• First Submitted: July 9, 2013
• First Posted: July 12, 2013
• Study Start: July 1, 2013
• Primary Completion: November 1, 2013
• Study Completion: November 1, 2013
• Last Updated: March 19, 2021
• Results First Posted: March 19, 2021

Record last verified: 2021-03

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)