Clinical trial NCT02589041: US-guided Sciatic Nerve Block: Evaluation of the Intraneural Ropivacaine Minimal Effective Volume (MEV90)
Official title: Ultrasound-guided Popliteal Sciatic Nerve Block: an Evaluation of the Intraneural
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: US-guided Sciatic Nerve Block
Keywords: intraneural sciatic block
Lead sponsor: ASST Gaetano Pini-CTO
Sponsor class: OTHER
First posted: 2015-10-28
Enrollment: 45
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: TREATMENT

Brief summary: 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.

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.

Eligibility criteria: 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

Primary outcomes:
measure: Evaluation of the Intraneural Ropivacaine Minimal Effective Volume in 90% of patients (MEV90)
timeFrame: 6 months
Secondary outcomes:
measure: electrophysiological assessment of neurological deficit
timeFrame: 5 weeks
Other outcomes:
Locations:
city: Milan
country: Italy
facility: Istituto Ortopedico G. Pini
state: Milano
Study officials:
affiliation: ASST Gaetano Pini-CTO
name: Gianluca Cappelleri, MD
role: PRINCIPAL_INVESTIGATOR
References: