US-guided Sciatic Nerve Block: Evaluation of the Intraneural Ropivacaine Minimal Effective Volume (MEV90)

Ultrasound-guided Popliteal Sciatic Nerve Block: an Evaluation of the Intraneural

This prospective, double-blinded study evaluates intraneural ropivacaine 1% Minimal Effective Volume (MEV90) for ultrasound-guided (US) popliteal sciatic nerve block, with Up-and-down methodology.

To evaluate any neurological complications, an electrophysiological assessment will also be performed preoperatively and at 5 weeks after surgery.

Study Overview

• Status: Completed
• Conditions: US-guided Sciatic Nerve Block
• Intervention / Treatment: Procedure: intraneural sciatic nerve injection; Drug: Ropivacaine 1%

Detailed Description

At least 45 patients undergoing hallux valgus repair will be enrolled. A baseline bilateral sciatic nerve electrophysiological study will be performed preoperatively.

Patients will be placed in prone position and a high-frequency (8-12 MHz) linear array transducer (Snerve, Sonosite, USA) will be used to identify the sciatic nerve in a transverse cross-sectional view at the apex of the popliteal fossa. As the best view of the sciatic nerve with its paraneural and neural sheath, just proximal to the point of bifurcation, will be obtained, the nerve dimension (medial-lateral and cranio-caudal diameters) will be determined and registered.

An 80 mm 22-gauge needle (Sonoplex, Pajunk, Germany) will be inserted using the US-guided in-plane technique under the epineurium. The positioning will be evaluated injecting 1 ml of sodium-chloride 0.9% solution and observing the nerve swelling, if correct the local anaesthetic (LA) solution will be injected.

The first patient will receive 15 ml of ropivacaine 1% (150 mg). Following patients will receive LA volume based on Up-and-down methodology.

Clinical follow-up will be performed at 12, 24, 48 hours, 1 and 5 weeks and 6 months after surgery.

At 5 weeks electrophysiological study will also be performed in all patients and repeated at 6 months in case of positive findings.

• Study Type: Interventional
• Enrollment (Actual): 45
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Italy
  • Milano
    • Milan, Milano, Italy, 20122
      • Istituto Ortopedico G. Pini

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Age above 18 years old
• ASA I-III
• Signed informed consensus

Exclusion Criteria:

• ASA IV
• Unstable neurological disease
• DM type I-II
• Allergy to ropivacaine-mepivacaine
• Opioid chronic treatment
• Consensus refusal or not valid
• Rheumatoid arthritis
• Baseline electrophysiological study positive finding
• Postoperative intensive care required

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Intraneural; Using an Up-and-down methodology, the first patient receives 15 ml ropivacaine 1% intraneural injection. If unsuccessful, following patient will receive an increased dose of LA (2 ml). If successful, following patient will be randomized to have either the same LA dose (9 out of 10 probability) or 2 ml reduction of LA dose (1 out of 10 probability)	Procedure: intraneural sciatic nerve injection; A popliteal intraneural sciatic nerve block will be performed under ultrasound guidance. Minimal effective volume will be evaluated performing a randomization based on the Up-and-down methodology. A baseline and postoperative electrophysiological study will assess the presence of any neurological complication.; Drug: Ropivacaine 1%

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Evaluation of the Intraneural Ropivacaine Minimal Effective Volume in 90% of patients (MEV90)	6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
electrophysiological assessment of neurological deficit	Electromyography of sciatic nerve bilaterally. Evaluation of velocity (m/Sec), amplitude (mV) and latency (mSec) of both peroneal and tibial components	5 weeks

Collaborators and Investigators

• Sponsor: ASST Gaetano Pini-CTO

Study record dates

Study Major Dates

• Study Start: November 1, 2015
• Primary Completion (Actual): October 1, 2016
• Study Completion (Actual): April 1, 2017

Study Registration Dates

• First Submitted: October 22, 2015
• First Submitted That Met QC Criteria: October 26, 2015
• First Posted (Estimate): October 28, 2015

Study Record Updates

• Last Update Posted (Actual): August 14, 2017
• Last Update Submitted That Met QC Criteria: August 11, 2017
• Last Verified: August 1, 2017

More Information

Terms related to this study

• Keywords: intraneural sciatic block
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Central Nervous System Depressants; Peripheral Nervous System Agents; Sensory System Agents; Anesthetics; Anesthetics, Local; Ropivacaine
• Other Study ID Numbers: IOGPGC10