Changes of Regional Tissue Oxygenation Saturation After Successful Femoral Nerve Block

Study Overview
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Brief Summary
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Regional tissue oxygenation saturation has been shown to increase in innervated regions after sympathetic block. The aim of this prospective observational study was to evaluate the changes of regional tissue oxygenation saturation by near-infrared spectroscopy after successful femoral nerve block with ropivacaine and determine whether the changes of regional tissue oxygenation saturation can be affected by the concentration of ropivacaine.

Detailed Description
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Successful peripheral nerve blocks induce sympathetic blockade, which increases local blood flow by vasodilation. The relationship between successful femoral nerve block and the variation of regional tissue oxygenation saturation was unclear.

Official Title
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Changes of Regional Tissue Oxygenation Saturation After Successful Femoral Nerve Block With Ropivacaine at Different Concentrations

Conditions
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Anesthesia, Local

Intervention / Treatment
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* Device: tissue oxygenation saturation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Informed consent American Society of Anesthesiologists physical statusⅠ-Ⅱ Undergo elective elective knee arthroscopy with peripheral nerve block Exclusion Criteria: Refusal to participate in the study BMI>35 Any contraindications to peripheral nerve block such as coagulation abnormalities, •Allergy to local anaesthetics, peripheral neuropathy

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 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 |
| --- | --- |
| H group<br>Patients scheduled for elective knee arthroscopy with peripheral nerve block will receive ultrasound-guided femoral nerve block with 0.5% ropivacaine. Regional tissue oxygenation saturation of the nerve innervation area and pinprick sensory tests at 5 min were assessed before the block and at 5-min intervals till 30 min after the block. | Device: tissue oxygenation saturation<br>* tissue oxygenation saturation<br>|
| L group<br>Patients scheduled for elective knee arthroscopy with peripheral nerve block will receive ultrasound-guided femoral nerve block with 0.25% ropivacaine. Regional tissue oxygenation saturation of the nerve innervation area and pinprick sensory tests were assessed at 5 min before the block and at 5-min intervals till 30 min after the block. | Device: tissue oxygenation saturation<br>* tissue oxygenation saturation<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Regional tissue oxygenation saturation after successful femoral nerve block | rSO2 | at 5-minute intervals till 30 minutes after regional block | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pinprick sensory scores | A 3-level scale was used to grade the intensity of sensory block using pinprick stimulation: 0=normal sensation; 1=analgesia; 2=anesthesia. | 5 minute before regional block and at 5-minute intervals till 30 minutes after regional block | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Peripheral nerve block