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

Phase 4

Completed

• Conditions: Orthopedic Surgical Procedures; Postoperative Pain
• Interventions: Procedure: Perineural Injection for Subgluteal Sciatic Nerve Block; Procedure: Intraneural Injection for Subgluteal Sciatic Nerve Block; Procedure: Femoral Nerve Block; Procedure: Patient-controlled postoperative analgesia; Drug: Mepivacaine

• Registration Number: NCT01981291
• Lead Sponsor: University of Parma

Brief 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.

Detailed 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.

Study Timeline

• Study Start: 2012-10
• Primary Completion: 2013-07
• Study Completion: 2013-10
• Status Verified: 2013-11
• Study First Submitted: 2013-11-04
• Study First Submitted QC: 2013-11-04
• Study First Posted: 2013-11-11
• Last Update Submitted: 2013-11-18
• Last Update Posted: 2013-11-19

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 120

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

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Perineural	Perineural Injection for Subgluteal Sciatic Nerve Block	Patients in this group will receive a perineural injection of mepivacaine for subgluteal sciatic nerve block, in addition to a femoral nerve block and patient-controlled postoperative analgesia.
Perineural	Femoral Nerve Block	Patients in this group will receive a perineural injection of mepivacaine for subgluteal sciatic nerve block, in addition to a femoral nerve block and patient-controlled postoperative analgesia.
Perineural	Patient-controlled postoperative analgesia	Patients in this group will receive a perineural injection of mepivacaine for subgluteal sciatic nerve block, in addition to a femoral nerve block and patient-controlled postoperative analgesia.
Perineural	Mepivacaine	Patients in this group will receive a perineural injection of mepivacaine for subgluteal sciatic nerve block, in addition to a femoral nerve block and patient-controlled postoperative analgesia.
Intraneural	Intraneural Injection for Subgluteal Sciatic Nerve Block	Patients in this group will receive an intraneural injection of mepivacaine for subgluteal sciatic nerve block, in addition to a femoral nerve block and patient-controlled postoperative analgesia.
Intraneural	Femoral Nerve Block	Patients in this group will receive an intraneural injection of mepivacaine for subgluteal sciatic nerve block, in addition to a femoral nerve block and patient-controlled postoperative analgesia.
Intraneural	Patient-controlled postoperative analgesia	Patients in this group will receive an intraneural injection of mepivacaine for subgluteal sciatic nerve block, in addition to a femoral nerve block and patient-controlled postoperative analgesia.
Intraneural	Mepivacaine	Patients in this group will receive an intraneural injection of mepivacaine for subgluteal sciatic nerve block, in addition to a femoral nerve block and patient-controlled postoperative analgesia.

Primary Outcome Measures

Name	Time	Method
Differences in Time to Resolution of Sciatic Nerve Block	<12 h	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.

Secondary Outcome Measures

Name	Time	Method
Success Rate of Anesthetic Nerve Blocks	≤30 min	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."
Incidence and Prevalence of Neurologic Disturbances	30 days	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.
Block Onset Time	≤30 min	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.

Trial Locations

Locations (1)

Anesthesia, Critical Care and Pain Medicine - University of Parma; 🇮🇹 Parma, PR, Italy