Duration of Sciatic Nerve Block After Injection of Local Anesthetic In or Around the Nerve

Postoperative Pain Clinical Trial

Official title:

Duration of Subgluteal Sciatic Nerve Block After Intra- or Perineural Injection of Mepivacaine: a Randomized, Controlled Trial

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT01981291
• Other study ID #: ANEST-ORT-03
• Status: Completed
• Phase: Phase 4
• First received: November 4, 2013
• Last updated: November 18, 2013
• Start date: October 2012
• Est. completion date: October 2013

Study information

• Verified date: November 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), leads to longer anesthesia and analgesia of the leg.

Some reports of accidental intraneural injection mention an extremely long duration. When different drugs and doses were evaluated in a clinical trial of intraneural injection, a longer-than-expected duration was reported.

The investigators will compare the two types of injection using the same drug, so as to determine if there is an actual difference in duration.

Description:

This randomized, controlled trial will investigate prospectively for differences in sensory and motor block duration after intra- or perineural injection of 1.5% (wt/vol) mepivacaine, a short-acting local anesthetic.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 120
• Est. completion date: October 2013
• Est. primary completion date: July 2013
• 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 signs of neuropathy in the ipsilateral extremity

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

Study Design

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

Related Conditions & MeSH terms

• Orthopedic Surgical Procedures
• Pain, Postoperative
• Postoperative Pain

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:
• Mepivacaine
Thirty milliliters of 1.5% (wt/vol) mepivacaine 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 (2)

Benhamou D, Blonski E, Lévy P, Plessis E, Chalhoub V. Ultra-long duration of a peripheral nerve block: a possible consequence of intraneural (subepineural) local anaesthetic injection. Ann Fr Anesth Reanim. 2010 Jul-Aug;29(7-8):589-91. doi: 10.1016/j.annfar.2010.05.032. Epub 2010 Jul 13. — View Citation

Nader A, Kendall MC, De Oliveira GS Jr, Puri L, Tureanu L, Brodskaia A, Asher Y, Parimi V, McCarthy RJ. A dose-ranging study of 0.5% bupivacaine or ropivacaine on the success and duration of the ultrasound-guided, nerve-stimulator-assisted sciatic nerve block: a double-blind, randomized clinical trial. Reg Anesth Pain Med. 2013 Nov-Dec;38(6):492-502. doi: 10.1097/AAP.0b013e3182a4bddf. — 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 the procedure)	No
Primary	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
Secondary	Block Onset Time	Time to onset of sciatic nerve anesthesia, defined as meeting at least the 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 min	No
Secondary	Success Rate of Anesthetic Nerve Blocks	The percentage of patients who attain the criteria for block success within 30 minutes of the injeciton.; 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	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	Yes