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

Phase 4

Completed

Conditions: Ankle Fusion
Tourniquet Hypertension
Intraoperative Hypertension
Total Ankle Arthroplasty

Interventions: Procedure: Perifemoral Injection of Local Anesthetic
Drug: Mepivacaine
Drug: Saline

Registration Number: NCT03390426

Lead Sponsor: Duke University

Brief Summary: 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: 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.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 31

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

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Saline Sham Group	Perifemoral Injection of Local Anesthetic	Injection of salt water (saline) above and beside the femoral artery.
Mepivacaine Block Group	Perifemoral Injection of Local Anesthetic	Injection of local anesthetic (mepivacaine) above and beside the femoral artery.
Saline Sham Group	Saline	Injection of salt water (saline) above and beside the femoral artery.
Mepivacaine Block Group	Mepivacaine	Injection of local anesthetic (mepivacaine) above and beside the femoral artery.

Primary Outcome Measures

Name	Time	Method
Number of Subjects Experiencing Tourniquet Hypertension	Intraoperatively (~3 hours)	Measuring systolic blood pressure using a cuff, aim to keep \<30mmHg change from baseline

Secondary Outcome Measures

Name	Time	Method
Amount of Esmolol Used Intraoperatively	Intraoperatively (~3 hours)	Amount of esmolol (in mg) used intraoperatively to decrease blood pressure after subject achieved tourniquet hypertension.
Pain Scores as Measured by the Numeric Rating Scale (NRS-11)	While in PACU (~1 hour)	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.
Amount of Opioid Pain Medications Used by Patient	Perioperative period (~4 hours)	Amount of opioid pain medication used by patient over a 4 hour period immediately after surgery. Opioids taken are converted to morphine equivalents.