Tourniquet HypertensionFABNCT07548567
A Long Axis Approach to the Femoral Artery Block (FAB) for Managing Tourniquet Pain and Hypertension in Below-the-Knee Fracture Surgery
A study testing Femoral artery block - short-axis and Femoral artery block - long-axis in people with Tourniquet Hypertension, run by National and Kapodistrian University of Athens at 1 site in Greece.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Tourniquet Hypertension
- What is being tested?
- Femoral artery block - short-axis and Femoral artery block - long-axis
- Type of treatment
- Injection or infusion, Surgery or procedure
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 84 participants
- Where
- 1 siteGreece
- Study dates
- 3 Jun 2026to Feb 2028
- Phase
- Interventional
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age >18 years
- Physical status ASA I-III
- Fluent in Greek or English
- Scheduled surgery: below-knee fractures
- Tourniquet duration ≥45 minutes
Who cannot join
- 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
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- Chronic pain therapy
- Diabetic neuropathy
- Uncontrolled hypertension
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Greece1 site, 1 recruiting
- Recruiting
University General Hospital Attikon
Athens, 124 61
LAMPRINI BANASIOU, +306981809083, banasiou_labrini@yahoo.com
About this study
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
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.
Read the 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.
- Conditions
- Tourniquet Hypertension
- Being tested
- Femoral artery block - short-axis, Femoral artery block - long-axis, Normal saline injection (control)
- Keywords
- FAB block, Tourniquet-induced hypertension, Tourniquet pain, Below-knee fracture surgery, Sympathetic blockade, intraoperative hypertension, sciatic nerve block, randomized controlled trial
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Femoral artery block - short-axisProcedure or surgery
Ultrasound-guided femoral artery block using short-axis in-plane technique with 10 mL ropivacaine 0.5%.
Femoral artery block - long-axisProcedure or surgery
Ultrasound-guided femoral artery block using long-axis in-plane technique with 10 mL ropivacaine 0.5%.
Normal saline injection (control)Other
Ultrasound-guided femoral artery injection using 10 mL 0.9% normal saline.
| Study group | Role | What they receive |
|---|---|---|
| Short-axis femoral artery block | Experimental | Ultrasound-guided femoral artery block using short-axis in-plane technique with 10 mL ropivacaine 0.5%. Receives: Procedure: Femoral artery block - short-axis |
| Long-axis femoral artery block | Experimental | Ultrasound-guided femoral artery block using long-axis in-plane technique with 10 mL ropivacaine 0.5%. Receives: Procedure: Femoral artery block - long-axis |
| Saline control injection | Placebo comparator | Ultrasound-guided femoral artery injection using in-plane technique with 10 mL 0.9% normal saline. Receives: Other: Normal saline injection (control) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of tourniquet-induced hypertension
Tourniquet-induced hypertension defined as an increase in systolic blood pressure greater than 30% from baseline values during tourniquet application.
Measured: From tourniquet inflation to 90 minutes intraoperatively
Secondary outcomes (10)
Heart rate
Changes in heart rate during tourniquet application at predefined time points.
Measured: From tourniquet inflation to 90 minutes intraoperatively
Intraoperative esmolol consumption
Total dose of esmolol administered for treatment of hypertension during surgery.
Measured: Intraoperative period
Intraoperative remifentanil consumption
Total remifentanil dose administered during surgery.
Measured: Intraoperative period
Postoperative pain score (VAS)
Pain intensity measured using Visual Analog Scale (0-10) in the recovery unit.
Measured: 0-60 minutes postoperative
Morphine consumption in recovery unit
Total morphine dose required for rescue analgesia in the postoperative recovery period.
Measured: 0-60 minutes postoperative
Femoral nerve block spread
Incidence of unintended femoral nerve blockade assessed by quadriceps strength and sensory testing.
Measured: Immediate postoperative period
Saphenous nerve block spread
Incidence of sensory block in saphenous nerve distribution assessed by pinprick test.
Measured: Immediate postoperative period
Imaging time
Time from ultrasound probe placement to optimal image acquisition.
Measured: During FAB block procedure
Needling time
Time from needle insertion to completion of local anesthetic or saline injection.
Measured: During FAB block procedure
Total block performance time
Total time required for ultrasound imaging, needle placement and completion of local anesthetic or saline injection.
Measured: During FAB block procedure
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Apr 2026
- Study start3 Jun 2026
- Primary completionOct 2027 (estimated)
- Study completionFeb 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Tourniquet HypertensionStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Investigator
- Enrolment
- 84 participants (estimated)
Sponsor and investigators
- Lead sponsor
- National and Kapodistrian University of Athens
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Banasiou Lamprini, National and Kapodistrian University of Athens
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07548567
- Sponsor's protocol ID
- 802/30-12-2025
- Acronym
- FAB
- Status last verified
- Jul 2026
- First submitted
- 16 Apr 2026
- Last updated
- 6 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No