The Effects of Various Concentrations of Ropivacaine on the Onset and Duration of Ankle Block

Study Overview
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Brief Summary
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Peripheral nerve blocks are essential in ensuring effective regional anesthesia and postoperative analgesia in forefoot surgery for hallux valgus repair. Many factors influence the onset and duration of peripheral nerve blocks. In the advent of ultrasound-guided nerve blocks, the accuracy in administering LA has significantly improved, potentially reducing the required dosage, which is also associated with less risk for toxicity. However, the effect of the concentration of LA on the onset time and duration of ultrasound-guided ankle blocks for forefoot surgery has not yet been studied. This poses a clinically relevant dilemma regarding the necessity of administering lower or higher concentrations of ropivacaine to achieve a clinically relevant faster onset time and longer duration of an ankle block.

Detailed Description
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This study aims to evaluate the differential effects of 0.25%, 0.5%, and 1% ropivacaine on the onset time and duration of ultrasound-guided ankle blocks in patients having forefoot surgery for anesthesia and postoperative analgesia. We hypothesize that the use of 1% ropivacaine for ultrasound guided ankle blocks will result in a significantly faster onset time and a longer sensory block duration, and thus analgesia, compared to the use of 0.25% and 0.5% ropivacaine in patients having forefoot surgery. The primary outcome is the difference in the duration of the sensory blocks. The secondary outcomes are the difference in onset time of the sensory block, the postoperative pain scores, and the opioid consumption.

Official Title
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The Effects of Various Concentrations of Ropivacaine on the Onset and Duration of Ankle Block - a Randomized, Triple-blinded, Parallel-group Interventional Study

Conditions
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Hallux Valgus, Anesthesia

Intervention / Treatment
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* Drug: 0.25% ropivacaine
* Drug: 0.5% ropivacaine
* Drug: 1% ropivacaine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Provide signed and dated informed consent Age 18 to 65 years, scheduled for elective forefoot surgery for hallux valgus repair under unilateral ankle block at ZOL Genk ASA physical I-II-III Able to understand the researchers Able to ambulate (ability to walk independently, with or without assistive devices) Able to learn and perform study sensory and motor assessment by exhibiting sensitivity to pinprick, cold, and light touch (tested beforehand with pinprick/cold/ light touch sensation test) as the patient will have to perform these sensory and motor assessments by him/herself at home at postoperative day 0 to 2 Exclusion Criteria: Language barrier Preexisting lower extremity neuropathy Contraindications to ankle block (local infection, edema, burn, soft tissue trauma, or distorted anatomy with scarring in the area of block placement) Contraindications for use of NSAIDs Allergy to local anesthetics Uncontrolled anxiety, psychiatric or neurological disorder that might interfere with study assessment Weight below 50 kg based on a maximum dose of 3 mg/kg ropivacaine and a maximum dose of 150 mg ropivacaine. Preoperative use of opioids or gabapentin less than 3 days before surgery

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 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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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 0.25% ropivacaine group<br>This group will receive a total of 15 mL of 0.25% ropivacaine. | Drug: 0.25% ropivacaine<br>* A total of 15 ml of 0.25% ropivacaine will be administered and distributed strategically among the specific nerves: 6 ml for the tibial nerve, 3 ml for the deep peroneal nerve, and 2 ml each for the superficial peroneal nerve, saphenous nerve, and sural nerve.<br>|
| Active Comparator: 0.5% ropivacaine group<br>This group will receive a total of 15 mL of 0.5% ropivacaine. | Drug: 0.5% ropivacaine<br>* A total of 15 ml of 0.5% ropivacaine will be administered and distributed strategically among the specific nerves: 6 ml for the tibial nerve, 3 ml for the deep peroneal nerve, and 2 ml each for the superficial peroneal nerve, saphenous nerve, and sural nerve.<br>|
| Experimental: 1% ropivacaine group<br>This group will receive a total of 15 mL of 1% ropivacaine. | Drug: 1% ropivacaine<br>* A total of 15 ml of 1% ropivacaine will be administered and distributed strategically among the specific nerves: 6 ml for the tibial nerve, 3 ml for the deep peroneal nerve, and 2 ml each for the superficial peroneal nerve, saphenous nerve, and sural nerve.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Duration | The difference in sensory block duration across the different groups. | 48 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Onset | The difference in sensory block onset across the different groups. | 30 minutes | 
| Pain scores | The difference in postoperative pain scores across the different groups. | 72 hours | 
| Opioid consumption | The difference in opioid consumption across the different groups. | One week | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Ropivacaine, Peripheral Nerve Block, Locoregional anesthesia, Onset, Duration, Sensory block