A Long Axis Approach to the Femoral Artery Block (FAB) for Managing Tourniquet Pain and Hypertension in Below-the-Knee Fracture Surgery
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Femoral artery block - short-axis, Femoral artery block - long-axis, Normal saline injection (control).
- Who it may be relevant to
- Registry conditions: Tourniquet Hypertension. Basic parameters: from 18 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Greece
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Official title
Turning the Probe, Changing the View: A Novel Long Axis Approach to the Femoral Artery Block (FAB) for Managing Tourniquet Pain and Hypertension in Below-the-Knee Fracture Surgery: A Prospective, Randomized, Double-Blind Controlled Trial
Overview
This is a prospective, randomized, double-blind controlled trial evaluating an ultrasound-guided femoral artery block (FAB) using a long-axis in-plane approach compared with a short-axis approach and a control group. The study will include adult patients (ASA I-III) undergoing below-the-knee fracture surgery with tourniquet application. All patients will receive standardized anesthesia including sciatic nerve block and total intravenous anesthesia. Participants will be randomized into three groups: short-axis FAB, long-axis FAB, or control (saline injection). The primary aim is to assess the effectiveness of the long-axis FAB in reducing tourniquet-induced hypertension. Secondary outcomes include hemodynamic stability, analgesic requirements, pain scores, block characteristics, and procedural performance metrics.
Detailed description
Tourniquet application during lower limb orthopedic surgery is associated with significant hemodynamic responses, including pain and tourniquet-induced hypertension (TH), which may increase perioperative cardiovascular risk. Femoral artery block (FAB) is a novel ultrasound-guided regional anesthesia technique targeting the perivascular sympathetic plexus surrounding the femoral artery to attenuate these responses.
Previous studies have described FAB using a short-axis in-plane ultrasound approach. This study proposes a novel long-axis in-plane ultrasound technique, hypothesizing that longitudinal visualization of the femoral artery may improve anatomical alignment with perivascular sympathetic structures, resulting in more effective sympathetic blockade, improved safety, and enhanced clinical efficacy.
This is a prospective, randomized, double-blind controlled trial including adult patients (ASA I-III) scheduled for below-the-knee fracture surgery requiring tourniquet application for at least 45 minutes. After informed consent and baseline assessment, patients will be randomized into three groups: (1) short-axis FAB with ropivacaine, (2) long-axis FAB with ropivacaine, and (3) control group receiving normal saline injection.
All patients will receive standardized anesthetic management including sciatic nerve block at the popliteal level and total intravenous anesthesia using propofol and remifentanil via Target-Controlled Infusion (TCI) under BIS monitoring. Hemodynamic variables (blood pressure and heart rate) will be recorded at predefined intraoperative and postoperative time points. Tourniquet-induced hypertension will be defined as a \>30% increase in systolic blood pressure from baseline.
Secondary outcomes include intraoperative opioid and vasopressor requirements, incidence of femoral and saphenous nerve spread, procedural performance metrics (imaging and needling time), postoperative pain scores (VAS), and opioid consumption in the recovery unit.
Data will be analyzed using repeated-measures and comparative statistical models to evaluate differences between groups over time and between interventions.
Interventions
- Procedure Femoral artery block - short-axis
Ultrasound-guided femoral artery block using short-axis in-plane technique with 10 mL ropivacaine 0.5%. - Procedure Femoral artery block - long-axis
Ultrasound-guided femoral artery block using long-axis in-plane technique with 10 mL ropivacaine 0.5%. - Other Normal saline injection (control)
Ultrasound-guided femoral artery injection using 10 mL 0.9% normal saline.
Primary outcome measures
- Incidence of tourniquet-induced hypertension [Time frame: From tourniquet inflation to 90 minutes intraoperatively]
Secondary outcome measures (10)
- Heart rate [Time frame: From tourniquet inflation to 90 minutes intraoperatively]
- Intraoperative esmolol consumption [Time frame: Intraoperative period]
- Intraoperative remifentanil consumption [Time frame: Intraoperative period]
- Postoperative pain score (VAS) [Time frame: 0-60 minutes postoperative]
- Morphine consumption in recovery unit [Time frame: 0-60 minutes postoperative]
- Femoral nerve block spread [Time frame: Immediate postoperative period]
- Saphenous nerve block spread [Time frame: Immediate postoperative period]
- Imaging time [Time frame: During FAB block procedure]
- Needling time [Time frame: During FAB block procedure]
- Total block performance time [Time frame: During FAB block procedure]
Eligibility criteria
Inclusion criteria
- Age >18 years
- Physical status ASA I-III
- Fluent in Greek or English
- Scheduled surgery: below-knee fractures
- Tourniquet duration ≥45 minutes
Exclusion criteria
- Refusal to participate
- Local inflammation at block site
- Known allergy to study drugs
- Morbid obesity (BMI >40)
- Communication inability
- Systemic neurological disease affecting peripheral nerves
- Chronic pain therapy
- Diabetic neuropathy
- Uncontrolled hypertension
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- Randomized
- Model
- Parallel assignment
- Masking
- Double blind
- Primary purpose
- Treatment
Study locations
Greece · 1 center
- University General Hospital Attikon — Athens
Identifiers
NCT: NCT07548567 · 802/30-12-2025