Efficacy of Ultrasound-Guided Local Anesthetic Injection Into or Around the Sciatic Nerve for Lower Limb Anesthesia

Foot Diseases Clinical Trial

Official title:

Intraneural Injection of Ropivacaine for Subgluteal Sciatic Nerve Block Leads to Faster Onset and Higher Success Rates: a Randomized, Controlled Trial

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01999647
• Other study ID #: ANEST-ORT-04
• Status: Completed
• Phase: N/A
• First received: November 25, 2013
• Last updated: December 2, 2013
• Start date: December 2011
• Est. completion date: December 2012

Study information

• Verified date: December 2013
• Source: University of Parma
• Contact: n/a
• Is FDA regulated: No
• Health authority: Italy: Ethics Committee
• Study type: Interventional

Clinical Trial Summary

This study was designed to assess whether the injection of local anesthetic into the nerve (intraneural), as opposed to around it (perineural), requires a shorter time to develop surgical anesthesia of the lower leg.

The investigators will compare the two types of injection using the same drug, so as to determine if there is an actual difference onset time. They will also examine the overall success rate of either kind of sciatic nerve blocks as the sole anesthetic for non-emergent orthopedic surgery.

The safety of these procedures will be examined by in-hospital and phone-call follow-up contacts.

Description:

This will be a randomized, controlled, patient- and observer-blinded trial assessing block characteristics after intra- or perineural injection of ropivacaine for subgluteal sciatic nerve blocks performed for elective surgery of the lower limb.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 64
• Est. completion date: December 2012
• Est. primary completion date: September 2012
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Undergoing non-emergent orthopedic procedure of knee, leg, foot with thigh tourniquet

• ASA Physical Status Class I-III

• Consenting to surgery under peripheral nerve block anesthesia (sciatic + femoral/saphenous block)

Exclusion Criteria:

• Unable to understand or communicate for the purpose of the study

• Exhibiting any neurological disturbance of the ipsilateral lower extremity

• Inability to satisfactorily image the sciatic nerve in the opinion of the attending anesthesiologist

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Outcomes Assessor), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Foot Diseases
• Injuries, Foot
• Injuries, Knee
• Injuries, Leg
• Knee Injuries
• Orthopedic Disorders

Intervention

Procedure:
• Intraneural Injection for Subgluteal Sciatic Nerve Block
The injection will start as the needle penetrates the outermost discernible layer of the nerve (epineurium) under ultrasound guidance. The injection will be adjudicated as "intraneural" if nerve cross section expansion and a reduction in echogenicity are observed. Short-axis real-time ultrasound imaging will be used, with an in-plane needle approach.
• Perineural Injection for Subgluteal Sciatic Nerve Block
The injection will start as the needle indents the outermost discernible layer of the nerve (epineurium) under ultrasound guidance. The injection will be adjudicated as "intraneural" if the drug infiltrates the space between the epimysium of the surrounding muscles and the outer epineurium of the sciatic nerve. Short-axis real-time ultrasound imaging will be used, with an in-plane needle approach.
• Femoral Nerve Block
Patients will receive an ultrasound-guided femoral nerve block using a short- or long-acting local anesthetic, as deemed indicated.
• Patient-Controlled Postoperative Analgesia
Patients will receive a patient-controlled intravenous or perineural catheter-based analgesia, depending on their preference and the anesthesiologist's indication.

Drug:
• Ropivacaine
Thirty milliliters of 0.75% (wt/vol) ropivacaine will be used for the sciatic nerve block.

Locations

Country	Name	City	State
Italy	Anesthesia, Critical Care and Pain Medicine — University of Parma	Parma	PR

Sponsors (1)

Lead Sponsor	Collaborator
University of Parma

Country where clinical trial is conducted

Italy, 

References & Publications (3)

Andersen HL, Andersen SL, Tranum-Jensen J. Injection inside the paraneural sheath of the sciatic nerve: direct comparison among ultrasound imaging, macroscopic anatomy, and histologic analysis. Reg Anesth Pain Med. 2012 Jul-Aug;37(4):410-4. doi: 10.1097/AAP.0b013e31825145f3. — View Citation

Robards C, Hadzic A, Somasundaram L, Iwata T, Gadsden J, Xu D, Sala-Blanch X. Intraneural injection with low-current stimulation during popliteal sciatic nerve block. Anesth Analg. 2009 Aug;109(2):673-7. doi: 10.1213/ane.0b013e3181aa2d73. — View Citation

Tran DQ, Dugani S, Pham K, Al-Shaafi A, Finlayson RJ. A randomized comparison between subepineural and conventional ultrasound-guided popliteal sciatic nerve block. Reg Anesth Pain Med. 2011 Nov-Dec;36(6):548-52. doi: 10.1097/AAP.0b013e318235f566. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Extra- vs. Intraneural Minimum Electrical Stimulation Thresholds	The minimum electrical nerve stimulation threshold will be recorded as a function of needle tip position.	During performance of nerve block (<30 min)	No
Primary	Onset Time of Sciatic Nerve Block	Time to onset of sciatic nerve anesthesia, defined as both following criteria: Sensory: does not feel pain or discomfort when pricked with a 25G needle.; Motor: able to slightly curl toes; unable to flex the ankle.	=30 minutes after block performance	No
Secondary	Success Rate of Sciatic Nerve Blocks	The percentage of patients who attain the criteria for block success within 30 minutes of the injection.; Investigators will also report the percentage of patients who successfully complete surgery without significant additional analgesia (see below); this will be defined as "clinical success rate."	=30 min after block performance	No
Secondary	Incidence and Prevalence of Neurologic Disturbances	Patients will be interviewed at ~4 h (block resolution visit), 7 days and (if necessary) at 30 days to assess for residual neurologic disturbances in the sciatic nerve territory.; The incidence/prevalence of these phenomena will be noted.	30 days after anesthesia performance	Yes
Secondary	Differences in Time to Resolution of Sciatic Nerve Block	The time at which sensory and motor function of the sciatic nerve have recovered at least to the following criteria: Sensory: patients feel discomfort when pricked with a thin needle (25G); Motor: patients may move both toes and ankle, albeit with reduced strength; This outcome measure will be examined by an investigator every 30-60 min and reported by patients as "time to return of sensation and movement". The investigator-reported value will be preferred if both are available.	<12 h	No