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

Not Applicable

Completed

• Conditions: Orthopedic Disorders; Foot Diseases; Injuries, Foot; Injuries, Knee; Injuries, Leg
• 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: Ropivacaine

• Registration Number: NCT01999647
• 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), 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.

Detailed 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.

Study Timeline

• Study Start: 2011-12
• Primary Completion: 2012-09
• Study Completion: 2012-12
• Study First Submitted: 2013-11-25
• Study First Submitted QC: 2013-11-25
• Status Verified: 2013-12
• Last Update Submitted: 2013-12-02
• Study First Posted: 2013-12-03
• Last Update Posted: 2013-12-04

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 64

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

• 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 for subgluteal sciatic nerve block under real-time, short-axis, in-plane ultrasound guidance, in addition to a femoral nerve block and patient-controlled postoperative analgesia. Ropivacaine will be used for the sciatic nerve block, whereas the choice of agent for the femoral nerve block is left to the attending anesthesiologist.
Perineural	Femoral Nerve Block	Patients in this group will receive a perineural injection for subgluteal sciatic nerve block under real-time, short-axis, in-plane ultrasound guidance, in addition to a femoral nerve block and patient-controlled postoperative analgesia. Ropivacaine will be used for the sciatic nerve block, whereas the choice of agent for the femoral nerve block is left to the attending anesthesiologist.
Perineural	Patient-Controlled Postoperative Analgesia	Patients in this group will receive a perineural injection for subgluteal sciatic nerve block under real-time, short-axis, in-plane ultrasound guidance, in addition to a femoral nerve block and patient-controlled postoperative analgesia. Ropivacaine will be used for the sciatic nerve block, whereas the choice of agent for the femoral nerve block is left to the attending anesthesiologist.
Intraneural	Intraneural Injection for Subgluteal Sciatic Nerve Block	Patients in this group will receive an intraneural injection for subgluteal sciatic nerve block under real-time, short-axis, in-plane ultrasound guidance, in addition to a femoral nerve block and patient-controlled postoperative analgesia. Ropivacaine will be used for the sciatic nerve block, whereas the choice of agent for the femoral nerve block is left to the attending anesthesiologist.
Intraneural	Femoral Nerve Block	Patients in this group will receive an intraneural injection for subgluteal sciatic nerve block under real-time, short-axis, in-plane ultrasound guidance, in addition to a femoral nerve block and patient-controlled postoperative analgesia. Ropivacaine will be used for the sciatic nerve block, whereas the choice of agent for the femoral nerve block is left to the attending anesthesiologist.
Intraneural	Patient-Controlled Postoperative Analgesia	Patients in this group will receive an intraneural injection for subgluteal sciatic nerve block under real-time, short-axis, in-plane ultrasound guidance, in addition to a femoral nerve block and patient-controlled postoperative analgesia. Ropivacaine will be used for the sciatic nerve block, whereas the choice of agent for the femoral nerve block is left to the attending anesthesiologist.
Perineural	Ropivacaine	Patients in this group will receive a perineural injection for subgluteal sciatic nerve block under real-time, short-axis, in-plane ultrasound guidance, in addition to a femoral nerve block and patient-controlled postoperative analgesia. Ropivacaine will be used for the sciatic nerve block, whereas the choice of agent for the femoral nerve block is left to the attending anesthesiologist.
Intraneural	Ropivacaine	Patients in this group will receive an intraneural injection for subgluteal sciatic nerve block under real-time, short-axis, in-plane ultrasound guidance, in addition to a femoral nerve block and patient-controlled postoperative analgesia. Ropivacaine will be used for the sciatic nerve block, whereas the choice of agent for the femoral nerve block is left to the attending anesthesiologist.

Primary Outcome Measures

Name	Time	Method
Onset Time of Sciatic Nerve Block	≤30 minutes after block performance	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.

Secondary Outcome Measures

Name	Time	Method
Success Rate of Sciatic Nerve Blocks	≤30 min after block performance	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."
Incidence and Prevalence of Neurologic Disturbances	30 days after anesthesia performance	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.
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.

Trial Locations

Locations (1)

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