Femoral Peri-arterial Local Anesthetic Injection Decreases Tourniquet Associated Ischemic Hypertension

Study Overview
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Brief Summary
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The purpose of this prospective randomized double-blind study is to determine if the novel technique of ultrasound guided peri-arterial injection of local anesthetic around the femoral artery decreases ischemic hypertension associated with prolonged lower extremity tourniquet time during total ankle arthroplasty (TAA) and foot fusion surgeries. Patients will be randomized 1:1 to receive either local anesthetic or saline, which will be injected superomedially to the femoral artery in an attempt to block sympathetic afferents and decrease tourniquet associated hypertension intraoperatively.

Detailed Description
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The purpose of this prospective randomized double-blind study is to determine if the novel technique of ultrasound guided peri-arterial injection of local anesthetic around the femoral artery decreases ischemic hypertension associated with prolonged lower extremity tourniquet time during total ankle arthroplasty (TAA) and foot fusion surgeries. Efficacy will be determined by analyzing incidence of intraoperative ischemic hypertension, defined as >30% increase in systolic blood pressure, associated with tourniquet inflation times greater than 90 minutes. The study will involve a total of 30 patients (15 in each group) and with a power of 80% to detect a 50% difference. The patients involved in the study will be ASA 1-3 patients who are undergoing either TAA or foot fusion surgeries. Patients will receive standard of care for their anesthesia, which at Duke Hospital includes placement of popliteal and saphenous perineural catheters and a general anesthetic with a laryngeal mask airway. Patients will be randomized to receive femoral peri-arterial injection with either 1.5% mepivacaine with 1:400,000 epinephrine or 0.9% saline which will be performed preoperatively at time of perineural catheter placement. Patients will assume standard risk associated with nerve blocks, including theoretical risk of nerve damage and local anesthetic systemic toxicity. Possible benefits include improved intraoperative hemodynamic stability, decreased intraoperative opioid and antihypertensive medications, and decreased tourniquet associated pain post-operatively.

Official Title
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Femoral Peri-arterial Local Anesthetic Injection Decreases Tourniquet Associated Ischemic Hypertension

Conditions
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Tourniquet Hypertension, Intraoperative Hypertension, Total Ankle Arthroplasty, Ankle Fusion

Intervention / Treatment
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* Drug: Mepivacaine
* Procedure: Perifemoral Injection of Local Anesthetic
* Drug: Saline


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients that will be included in the study are English speaking 18-75 year old ASA 1-3 patients undergoing total ankle arthroplasty. Exclusion Criteria: ASA 4 or 5 Diagnosis of chronic pain Daily chronic opioid use (over 3 months of continuous opioid use). Inability to communicate pain scores or need for analgesia. Infection at the site of block placement Age under 18 years old or greater than 75 years old Pregnant women (as determined by standard of care day-of surgery urine bHCG) Intolerance/allergy to local anesthetics Weight <50 kg Suspected, or known addiction to or abuse of illicit drug(s), prescription medicine(s), or alcohol within the past 2 years. Uncontrolled anxiety, schizophrenia, or other psychiatric disorder that, in the opinion of the investigator, may interfere with study assessments or compliance. Current or historical evidence of any clinically significant disease or condition that, in the opinion of the investigator, may increase the risk of surgery or complicate the subject's postoperative course

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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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Supportive Care
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Mepivacaine Block Group<br>Injection of local anesthetic (mepivacaine) above and beside the femoral artery. | Drug: Mepivacaine<br>* An ultrasound guided injection of mepivacaine superomedially to the femoral artery.<br>* Other names: Carbocaine;Procedure: Perifemoral Injection of Local Anesthetic<br>* An ultrasound guided injection of mepivacaine superomedially to the formal artery in an effort to numb the nerves that contribute to tourniquet hypertension intraoperatively.<br>* Other names: Femoral periarterial injection;|
| Placebo Comparator: Saline Sham Group<br>Injection of salt water (saline) above and beside the femoral artery. | Procedure: Perifemoral Injection of Local Anesthetic<br>* An ultrasound guided injection of mepivacaine superomedially to the formal artery in an effort to numb the nerves that contribute to tourniquet hypertension intraoperatively.<br>* Other names: Femoral periarterial injection;Drug: Saline<br>* An ultrasound guided injection using a medication that does NOT numb any nerves called saline, or salt water.<br>* Other names: Salt Water placebo;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of Subjects Experiencing Tourniquet Hypertension | Measuring systolic blood pressure using a cuff, aim to keep <30mmHg change from baseline | Intraoperatively ( 3 hours) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain Scores as Measured by the Numeric Rating Scale (NRS-11) | The Numeric Rating Scale (NRS-11) is an 11-point scale for patient self-reporting of pain. 0 = No Pain, 1-3 = Mild Pain, 4-6 = Moderate Pain, 7-10 = Severe Pain. | While in PACU ( 1 hour) | 
| Amount of Opioid Pain Medications Used by Patient | Amount of opioid pain medication used by patient over a 4 hour period immediately after surgery. Opioids taken are converted to morphine equivalents. | Perioperative period ( 4 hours) | 
| Amount of Esmolol Used Intraoperatively | Amount of esmolol (in mg) used intraoperatively to decrease blood pressure after subject achieved tourniquet hypertension. | Intraoperatively ( 3 hours) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Perifemoral, Tourniquet, Mepivacaine, Tourniquet Hypertension