Comparing Through-the-Needle With Suture-Method Catheter Designs for Popliteal Nerve Blocks

Not Applicable

Completed

Conditions: Sciatic Nerve Block
Regional Anesthesia

Interventions: Device: Suture-Method Technique
Device: Through-the-Needle Technique

Registration Number: NCT03442036

Lead Sponsor: University of California, San Diego

Brief Summary: Following painful surgical procedures, postoperative analgesia is often provided with a single-injection peripheral nerve block. Hothe investigatorsver, even with the longest-acting FDA-approved local anesthetic currently available-bupivacaine-the block duration is measured in hours, while the surgical pain may persist for days. A continuous peripheral nerve block allows a prolonged block, consisting of a percutaneously-inserted catheter with its orifice adjacent to a target nerve/plexus through which local anesthetic may be administered. Two basic perineural catheter designs currently exist: (1) catheters that are inserted either through or over a straight hollow-bore needle; and, (2) catheters that are attached to the back of a hollow suture-shaped needle that pulls the catheter adjacent to the target nerve ("suture-method" design). To date, a comparison of the relative risks and benefits of these two designs have not been investigated. The investigators therefore propose a randomized, observer-masked, controlled, parallel-arm, clinical trial to compare these two catheter designs when used to provide post-surgical analgesia following foot and ankle surgery.

Detailed Description: This investigation will be a randomized, observer-masked, controlled, parallel-arm, human-subjects clinical trial. Of note, the investigators will be using standard-of-care perineural catheters and local anesthetic under their FDA-approved purpose and do not plan to research a possible change of indication or use of these drugs as part of this research project.

Consenting adults undergoing surgery with a planned popliteal-sciatic perineural catheter placement will be offered enrollment. Study inclusion will be proposed to eligible patients prior to surgery. If a patient desires study participation, written, informed consent will be obtained using a current UCSD IRB-approved ICF.

Following written, informed consent, the investigators will collect baseline anthropomorphic information (age, sex, height, and the investigatorsight). Subjects will be then be randomized using a computer-generated list and opaque, sealed envelopes to one of two treatment groups (blocks of 4, no stratification): perineural catheter insertion using (1) through-the-needle technique or (2) suture technique. All catheters will be placed by a regional anesthesia fellow or resident under the direct supervision and guidance of a regional anesthesia attending (or by the attending him/herself).

All subjects will have a peripheral intravenous (IV) catheter inserted, standard noninvasive monitors applied, supplemental oxygen administered via a nasal cannula or face mask, and positioned prone. Midazolam and fentanyl (IV) will be titrated for patient comfort, while ensuring that patients remain responsive to verbal cues. The area that will be subsequently covered by the catheter dressing will be clipped of hair, if necessary. The ultrasound will be placed to visualize the short axis (cross-section) of the sciatic nerve to identify the sciatic nerve bifurcation which will subsequently be marked, as well as the location 5 cm cephalad to the bifurcation. The area will be cleaned with chlorhexidine gluconate and isopropyl alcohol and a clear, sterile, fenestrated drape applied. The ultrasound probe will be placed to visualize the short-axis (cross-section) of the target nerve(s) and the target for the catheter to intercept the nerve may be anywhere between the bifurcation and 5 cm cephalad to the bifurcation. All catheters will be placed using standard UCSD ultrasound-guided perineural catheter techniques as previously described. Normal saline 5-20 mL will be administered via the needle and/or catheter to allow catheter insertion and/or testing of catheter location (viewed with ultrasound).

Local anesthetic (20 mL, lidocaine 2% with epinephrine 1:200,000-400,000) will be administered via the catheter. A "successful" catheter insertion will be defined as sensory-block onset in the tibial nerve distribution within 30 minutes following the local anesthetic injection. If the nerve block fails, the catheter will be replaced or the patient removed from further study.

An infusion pump will be attached to the patient's perineural catheter and initiated within the recovery room. The pump will provide ropivacaine 0.2% at a 6 mL/h basal rate infusion and a 4 mL patient-controlled bolus with a 30 minute lockout (standard at UCSD). Subjects will be discharged with a prescription for oxycodone 5 mg tablets for supplementary analgesia. Subjects will be contacted via phone for 4 days following surgery to collect study outcome measures: worst, average, least, and current surgical pain (Numeric Rating Scale of 0 to 10, with "0" being no pain and "10" being the worst pain ever experienced), analgesic use (oral opioids and infusion boluses), sleep disturbances, opioid and local anesthetic infusion side effects, local anesthetic leakage, gross catheter dislodgement, sensory and motor block, and satisfaction with pain control. Subjects or their caretakers will remove the catheters at home.

Primary endpoint:

Hypothesis 1: Surgical pain will be noninferior within the first 2 days following foot/ankle surgery with a suture-method compared with a through-the-needle perineural catheter when used for a continuous popliteal-sciatic nerve block to provide postoperative analgesia (the mean "average" pain measured daily with a Numeric Rating Scale).

Hypothesis 2: Opioid consumption will be noninferior within the first 2 days following foot/ankle surgery with a suture-method compared with a through-the-needle perineural catheter when used for a continuous popliteal-sciatic nerve block to provide postoperative analgesia (cumulative dose).

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 70

Inclusion Criteria

Patients undergoing ambulatory foot or ankle surgery with a popliteal perineural catheter for postoperative analgesia.

Exclusion Criteria

Pregnancy
Inability to communicate with research staff
Incarceration
Clinically apparent neuropathy in the operative extremity
Chronic high dose opioid use
History of opioid abuse
Concurrent surgery outside the block distribution
Patients with nerves deeper than 5 cm from the skin

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Suture-Method Technique	Suture-Method Technique	Perineural catheters are attached to the back of a hollow suture-shaped needle that pulls the catheter adjacent to the target nerve. The perineural catheter will then be used to infuse local anesthetic directly onto the nerve to provide postoperative pain control.
Through-the-Needle Technique	Through-the-Needle Technique	Perineural catheters are inserted through a straight hollow-bore needle. The perineural catheter will then be used to infuse local anesthetic directly onto the nerve to provide postoperative pain control.

Primary Outcome Measures

Name	Time	Method
Average Pain	first two postoperative days combined	Pain evaluated using a numeric rating scale with 0 = no pain and 10 = worst imaginable pain

Secondary Outcome Measures

Name	Time	Method
Opioid Consumption	first two postoperative days	Cumulative opioid consumption (oxycodone) measured in milligrams
Worst Pain	Postoperative Days 1 and 2	The worst pain score for the day evaluated using a numeric rating scale with 0 = no pain and 10 = worst imaginable pain