Using femoral vein size to predict low blood pressure after spinal anesthesia in older adults having orthopedic surgery

Evaluation of Femoral Vein Diameter to Predict Intraoperative Hypotension in Geriatric Patients Undergoing Orthopedic Surgery Under Spinal Anesthesia: A Prospective Observational Study

This test will see if the width of the right common femoral vein on ultrasound can predict drops in blood pressure after spinal anesthesia in people over 60 having elective lower-limb orthopedic surgery.

Quick facts

• Study type: Observational
• Enrollment: 43 (estimated)
• Ages: 60 Years and up
• Sex: All
• Sponsor: Cairo University (other)
• Locations: 1 site (Cairo)
• Trial ID: NCT07339475 on ClinicalTrials.gov

What this trial studies

This observational study will measure the transverse diameter of the right common femoral vein (RCFV) in the inguinal region by ultrasound before spinal anesthesia and track blood pressure changes during elective lower-limb orthopedic operations in patients over 60. Investigators will enroll ASA I–II patients with BMI ≤35 and record perioperative hemodynamics to determine whether a smaller or larger RCFV correlates with post-spinal hypotension. The protocol uses bedside ultrasound as a noninvasive marker of intravascular volume status and compares the RCFV measurement with observed blood pressure drops after spinal block. The work builds on obstetric data and aims to test the method's applicability in a geriatric surgical population.

Who should consider this trial

Good fit: Ideal candidates are adults older than 60, ASA physical status I–II, BMI ≤35, scheduled for elective lower-limb orthopedic surgery under spinal anesthesia and willing to undergo a preoperative femoral vein ultrasound.

Not a fit: Patients unlikely to benefit include those with BMI >35, contraindications to spinal anesthesia (for example coagulopathy or active infection at the puncture site), emergency surgeries, or those not receiving spinal anesthesia.

Why it matters

Potential benefit: If successful, a quick bedside femoral vein ultrasound could help clinicians identify older patients at higher risk of blood pressure drops after spinal anesthesia so they can plan monitoring or preventive measures.

How similar studies have performed: Previous studies—mostly in cesarean delivery populations—have shown promising results using femoral or venous ultrasound measures to predict post-spinal hypotension, but evidence in geriatric orthopedic patients is limited.

Eligibility criteria

Inclusion Criteria:

* Age \> 60 years.
* American Society of Anesthesiologists (ASA) physical state I-II.
* Body mass index (BMI) ≤35 kg/m². Patients above this value will be excluded because obesity may cause technical difficulty and poor image quality in femoral vein ultrasound assessment.
* Elective lower-limb orthopedic surgery under spinal anesthesia.

Exclusion Criteria:

* Patients refusing to participate.
* History of psychiatric illness or seizures.
* Absolute contraindications to spinal anesthesia: infection at the puncture site, severe coagulopathy/anticoagulation \[defined as platelet count \<75,000/µL, International Normalized Ratio (INR) \>1.5, Activated Partial Thromboplastin Time (aPTT) \>1.5 times control, or the use of anticoagulants such as warfarin, heparin, low molecular weight heparin, or direct oral anticoagulants within the recommended safety interval for neuraxial anesthesia\], severe hypovolemia, increased intracranial pressure, or known allergy to local anesthetics.
* Severe cardiac disease, including left ventricular ejection fraction \<30%, Severe valvular heart disease (e.g., critical aortic stenosis), clinically significant arrhythmias (atrial fibrillation with uncontrolled ventricular rate \>120 bpm, frequent ventricular ectopy or sustained ventricular tachyarrhythmia) and congestive heart failure such as New York Heart Association (NYHA) class III-IV.
* Severe uncontrolled hypertension, defined as persistent mean arterial pressure (MAP) ≥120 mmHg or systolic blood pressure (SBP) ≥180 mmHg and/or diastolic blood pressure (DBP) ≥110 mmHg despite medical therapy.
* Severe respiratory diseases (Global Initiative for Chronic Obstructive Lung Disease (GOLD) stage III-IV chronic obstructive pulmonary disease, or forced vital capacity (FVC) \<50% predicted).
* Baseline bradycardia (\<50) or mean arterial blood pressure less than 60mmHg.
* Emergency surgeries.

Where this trial is running

Cairo

• Cairo University — Cairo, Egypt (RECRUITING)

Study contacts

• Study coordinator: Hebatullah S Abdelhamid, MD

Conditions: Femoral Vein Diameter, Intraoperative Hypotension, Orthopedic Surgery, Spinal Anesthesia