Ultrasound Guided Distal Sciatic Nerve Block - a Comparison With Nerve Stimulator Technique

Ultrasound Guided Distal Sciatic Nerve Block - a Randomised Comparison With Nerve Stimulator Technique

For distal sciatic nerve block this prospective, randomised comparison with ultrasound guided distal subepineural block tested the hypothesis, that intraepineural injection of local anesthetic using nerve stimulation technique is common and associated with high success rate.

Study Overview

• Status: Completed
• Conditions: Other Surgical Procedures
• Intervention / Treatment: Drug: midazolam; Drug: Prilocaine 1%; Drug: Ropivacaine 0.75%; Drug: Prilocaine 1%; Device: ultrasound guidance; Device: nerve stimulation technique

Detailed Description

Classical methods for nerve localization (loss of resistance, cause of paresthesias, nerve stimulation technique)assumed that the target is a close approximation to the nerve, without epineural perforation. Intraneural injections were considered as evitable, with high risk for nerve damages.

Ultrasound guidance provided for the first time a real-time visualization of the spread of local anesthetic. Some recent studies proved, that an intraneural injection using nerve stimulator technique is common and not necessarily accompanied with nerve damages.

In the ultrasound group (group US) the investigators tested the hypothesis, that an intraneural injection of local anesthetic generate a high success rate and a short onset time without clinical apparent nerve damages.

In the nerve-stimulation group (group NS) the investigators tested the hypothesis, that an intraneural injection of local anesthetic is common, and in case of intraneural injection accompanied likewise with high success rate and shorter onset time.

For the sciatic division the investigators tested the hypothesis, that classical methods of nerve localization (nerve-stimulation technique, cause of paresthesias) are not able to avoid epineural perforation.

• Study Type: Interventional
• Enrollment (Actual): 250
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 75 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• elective surgery on the foot or ankle
• tourniquet distal of the knee
• adult patients, 18-75 years old
• ASA-risk-groups I-III (American Society of Anesthesiologists)
• informed consent

Exclusion Criteria:

• severe coagulopathy
• systemic inflammatory response
• ASA-risk-groups > III (American Society of Anesthesiologists)
• drug allergy: local anesthetics
• pregnancy, lactation period
• participation in other studies
• addiction to drugs or alcohol
• non-cooperative patients

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: NONE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
ACTIVE_COMPARATOR: group US; Ultrasound guided block : 20ml Prilocaine 1% and 10ml Ropivacaine 0.75% (30ml Prilocaine 1% in outpatients)	Drug: midazolam; Prior to performing the regional anesthesia the investigators administered midazolam as a premedication by mouth (3,75-7,5mg) or intravenously (2-3mg).; Other Names: Dormicum; Drug: Prilocaine 1%; 20ml Prilocaine 1% for distal sciatic nerve block (30ml Prilocaine 1% in outpatients); Other Names: Xylonest; Drug: Ropivacaine 0.75%; 10ml Ropivacaine 0.75% for distal sciatic nerve block (not in outpatients); Other Names: Naropin; Drug: Prilocaine 1%; 10ml Prilocaine 1% for saphenous nerve block; Other Names: Xylonest; Device: ultrasound guidance; In group US the sciatic nerve localization and needle guidance is realized using ultrasound.
ACTIVE_COMPARATOR: group NS; Nerve stimulation technique: 20ml Prilocaine 1% and 10ml Ropivacaine 0.75% (30ml Prilocaine 1% in outpatients)	Drug: midazolam; Prior to performing the regional anesthesia the investigators administered midazolam as a premedication by mouth (3,75-7,5mg) or intravenously (2-3mg).; Other Names: Dormicum; Drug: Prilocaine 1%; 20ml Prilocaine 1% for distal sciatic nerve block (30ml Prilocaine 1% in outpatients); Other Names: Xylonest; Drug: Ropivacaine 0.75%; 10ml Ropivacaine 0.75% for distal sciatic nerve block (not in outpatients); Other Names: Naropin; Drug: Prilocaine 1%; 10ml Prilocaine 1% for saphenous nerve block; Other Names: Xylonest; Device: nerve stimulation technique; In the group NS sciatic nerve localization and needle guidance is realized using nerve stimulation technique. However, ultrasound is used observing (Observer) the procedure, but blinded for the physician (Anesthetist) performing the block.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Success Rate Without Supplementation	After injection of local anesthetic a waiting period of 30-60 minutes was defined before completing a failed block.; success without supplementation = no additional analgetics or rescue blocks required (success rate without supplementation, outcome measure 1); success with supplementation = analgetics or selective rescue blocks distal of the sciatic division required (success rate without supplementation and additionally all supplemented blocks, outcome measure 3); failed block = change of anesthetic procedure (general, spinal) or rescue blocks proximal of the sciatic division	within 30-60 minutes after injection of the local anesthetic
Time Until Readiness for Surgery (Minutes)		within 60 minutes after injection of the local anesthetic
Success Rate With Supplementation	After injection of local anesthetic a waiting period of 30-60 minutes was defined before completing a failed block.; success without supplementation = no additional analgetics or rescue blocks required (success rate without supplementation, outcome measure 1); success with supplementation = analgetics or selective rescue blocks distal of the sciatic division required (success rate without supplementation and additionally all supplemented blocks, outcome measure 3); failed block = change of anesthetic procedure (general, spinal) or rescue blocks proximal of the sciatic divisionSucces rate with supplementation	later than 30-60 minutes after injection of the local anesthetic

Collaborators and Investigators

• Sponsor: Helios Research Center
• Investigators: Study Director: Georg Rehmert, Dr. med., Klinik für Anästhesiologie und Intensivtherapie, Helios Kliniken Schwerin, Wismarsche Strasse 393-7, DE-19049 Schwerin

Study record dates

Study Major Dates

• Study Start: November 1, 2010
• Primary Completion (ACTUAL): June 1, 2012
• Study Completion (ACTUAL): September 1, 2012

Study Registration Dates

• First Submitted: July 16, 2012
• First Submitted That Met QC Criteria: July 17, 2012
• First Posted (ESTIMATE): July 18, 2012

Study Record Updates

• Last Update Posted (ESTIMATE): November 1, 2013
• Last Update Submitted That Met QC Criteria: August 27, 2013
• Last Verified: August 1, 2013

More Information

Terms related to this study

• Keywords: Ultrasound; Orthopedic Surgery; Sciatic Nerve; Anesthesia, Regional
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Central Nervous System Depressants; Peripheral Nervous System Agents; Sensory System Agents; Anesthetics, Intravenous; Anesthetics, General; Anesthetics; Tranquilizing Agents; Psychotropic Drugs; Hypnotics and Sedatives; Adjuvants, Anesthesia; Anti-Anxiety Agents; GABA Modulators; GABA Agents; Anesthetics, Local; Midazolam; Prilocaine; Ropivacaine
• Other Study ID Numbers: HV 2010 003