Protective Nerve Stimulation in Regional Anesthesia

Study Overview
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Brief Summary
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Peripheral nerve blocks can be conducted with ultrasound, electrical nerve stimulation or landmark technique or a combination of this techniques. Whether a regional block should be conducted with a combination of those different possibilities is highly discussed. In this study the investigators want to show the effectiveness of new standard way of combined use of ultrasound and nerve stimulation, they call protective nerve stimulation. According to ethical vote we are conducting an observational study.

Detailed Description
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All patients will get the regional block they need for the elective surgery. Before starting the block a standard monitoring will be established. After applying the monitoring the block will be performed by an experienced anesthetist in supervision of another experienced anesthetist. The nerve stimulator is set on a fixed current of 1.0 mA and a block without motoric response on this current is tried. Ultrasound images are saved. After performing the regional anesthesia the further anesthetic procedure will be carried out and the surgery will take place. After surgery the patients will be transported to the recovery room or Postanesthesia care unit.

Official Title
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The Use of Protective Nerve Stimulation in Different Regional Anesthetic Blocks (Interscalene, Axillary, Femoral and Sciatic Nerve Blocks)

Conditions
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Anesthesia, Local, Nerve Block, Brachial Plexus Block

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: written informed consent age of 18 or older elective surgery patients at Campus Charité Mitte with clinical benefit of regional anesthesia Exclusion Criteria: existing contraindication for regional nerve blocks or the use of Protective Nerve Stimulation patients who undergo outpatient treatment allergy against local anesthetics age under 18 years Lacking willingness to take part in the study ASA PS score of 4 or more preexisting neural damage in the effect area Diabetes mellitus, alcohol use disorder Participation in other prospective clinical interventional trials Accommodation in an institution due to an official or judicial order

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Standard of care: SCI<br>Patients at Charite, with lower limb surgery undergoing a protective performed ultrasound guided sciatic nerve block. N=15. | |
| Standard of care: FEM<br>Patients at Charite, with lower limb surgery undergoing a protective performed ultrasound guided femoral nerve block. N=15. | |
| Standard of care: ISB<br>Patients at Charite, with upper limb surgery undergoing a protective performed ultrasound guided interscalene plexus block. N=15. | |
| Standard of care: AXP<br>Patients at Charite, with upper limb surgery undergoing a protective performed ultrasound guided axillary plexus block. N=15. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Effectivity | Effective motor blockade and sensitive blockade at fixed timepoints | Duration of preparation, surgery and recovery room (an average of 4 hours) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Muscle contractions | Number of expected and unexpected muscle contractions | Duration of preparation, surgery and recovery room (an average of 4 hours) | 
| Paresthesia | Number of expected and unexpected paresthesia | Duration of preparation, surgery and recovery room (an average of 4 hours) | 
| Pain while blocking | Does the patient have pain while blocking? Pain during hospital stay will be measured with the Numeric Rating Scale (NRS-V). For patients unable of pain self-assessment (e.g. ventilated patients, patients in delirious state or patients with stroke affecting language skills) observer-rated pain scales will be applied: Behavioural Pain Scale (BPS for ventilated) and BPS-NI (for non-ventilated) patients. | Duration of preparation, surgery and recovery room (an average of 4 hours) | 
| Pain after surgery | Does the patient have pain after surgery? Pain during hospital stay will be measured with the Numeric Rating Scale (NRS-V). For patients unable of pain self-assessment (e.g. ventilated patients, patients in delirious state or patients with stroke affecting language skills) observer-rated pain scales will be applied: Behavioural Pain Scale (BPS for ventilated) and BPS-NI (for non-ventilated) patients. | Duration of preparation, surgery and recovery room (an average of 4 hours) | 
| Satisfaction | Satisfaction of the patient in a 6-step Likert scale | Duration of preparation, surgery and recovery room (an average of 4 hours) | 
| Impedance | impedance measured by the nerve stimulator while proceeding with the needle | Duration of preparation, surgery and recovery room (an average of 4 hours) | 
| Changes of impedance | changes of impedance measured by the nerve stimulator while proceeding with the needle | Duration of preparation, surgery and recovery room (an average of 4 hours) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Protective Nerve Stimulation, Regional Anesthesia, Sciatic nerve block, femoral nerve block, brachial plexus block