Femoral Vein Collapsibility Index and Post-Spinal Hypotension in Pregnant Women: Impact of Position

NCT06885593 | Not Yet Recruiting

• 1 other identifier: 2025/7
• Study Type: interventional
• Target: 100
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to improve the safety of spinal anesthesia for pregnant patients undergoing elective cesarean delivery. Specifically, the investigators are investigating whether ultrasound measurements of a vein in the groin (the right common femoral vein, or RCFV) can help predict the risk of low blood pressure (hypotension) after spinal anesthesia. The main question it aims to answer is: Can femoral vena cava collapsibility index predict post-spinal hypotension in pregnant women in left lateral tilt position? Before receiving spinal anesthesia, participants will undergo a brief and painless ultrasound examination of the RCFV in the groin area while lying in a specific position."

Conditions

Spinal Induced Hypotension in Cesarean Delivery

Outcome Measures

Primary Outcomes (1)

• Number of Participants with Post-Spinal Hypotension

  Post-Spinal Hypotension Measured by Systolic and Diastolic Blood Pressure and Heart Rate Changes Following Spinal Anesthesia in Supine and Left Lateral Tilt Positions Systolic Blood Pressure, Diastolic Blood Pressure, and Heart Rate are now presented as separate outcome measures, each with its own unit of measure.

  40 minute

Secondary Outcomes (1)

• Number of Participants with time of onset of maternal hypotension, symptomatic hypotension, incidence of bradycardia, cumulative ephedrine requirements, patient satisfaction

  24 hours

Study Arms (2)

Supine Position

SHAM COMPARATOR

All ultrasonography (USG) procedures will be performed by the same anesthesiologist using a Ultrasound device before the start of spinal anesthesia (SA) and after baseline blood pressure and heart rate have been measured. Patients will be placed in supine position. After at least 3 minutes in each position, ultrasound of the inferior vena cava (IVC) and femoral vein (FV) will be performed. The oblique probe will be placed below the xiphoid. Anteroposterior diameters and peak velocities of the IVC will be measured 2-3 cm below the IVC-right atrium For standardization purposes, measurements of the right femoral vein will be used in the study. The FV will be visualized with B-mode ultrasound 2-5 cm below the level of the inguinal ligament where the femoral artery is best palpated, without applying any pressure that may affect the FV diameter.

Diagnostic Test: Supine Position; Diagnostic Test: Left Lateral Tilt Position

Left Lateral Tilt Position

ACTIVE COMPARATOR

All ultrasonography (USG) procedures will be performed by the same anesthesiologist using a Ultrasound device before the start of spinal anesthesia (SA) and after baseline blood pressure and heart rate have been measured. Patients will be placed in left lateral tilt (LLT) positions. After at least 3 minutes in each position, ultrasound of the inferior vena cava (IVC) and femoral vein (FV) will be performed. The oblique probe will be placed below the xiphoid. Anteroposterior diameters and peak velocities of the IVC will be measured 2-3 cm below the IVC-right atrium For standardization purposes, measurements of the right femoral vein will be used in the study. The FV will be visualized with B-mode ultrasound 2-5 cm below the level of the inguinal ligament where the femoral artery is best palpated, without applying any pressure that may affect the FV diameter.

Diagnostic Test: Supine Position; Diagnostic Test: Left Lateral Tilt Position

Interventions

Supine Position DIAGNOSTIC_TEST

All ultrasonography (USG) procedures will be performed by the same anesthesiologist using a Ultrasound device before the start of spinal anesthesia (SA) and after baseline blood pressure and heart rate have been measured. Patients will be placed in supine and left lateral tilt (LLT) positions. After at least 3 minutes in each position, ultrasound of the inferior vena cava (IVC) and femoral vein (FV) will be performed. The oblique probe will be placed below the xiphoid. Anteroposterior diameters and peak velocities of the IVC will be measured 2-3 cm below the IVC-right atrium For standardization purposes, measurements of the right femoral vein will be used in the study. The FV will be visualized with B-mode ultrasound 2-5 cm below the level of the inguinal ligament where the femoral artery is best palpated, without applying any pressure that may affect the FV diameter.

Left Lateral Tilt Position; Supine Position

Left Lateral Tilt Position DIAGNOSTIC_TEST

All ultrasonography (USG) procedures will be performed by the same anesthesiologist using a Ultrasound device before the start of spinal anesthesia (SA) and after baseline blood pressure and heart rate have been measured. Patients will be placed in left lateral tilt (LLT) position. After at least 3 minutes in each position, ultrasound of the inferior vena cava (IVC) and femoral vein (FV) will be performed. The oblique probe will be placed below the xiphoid. Anteroposterior diameters and peak velocities of the IVC will be measured 2-3 cm below the IVC-right atrium For standardization purposes, measurements of the right femoral vein will be used in the study. The FV will be visualized with B-mode ultrasound 2-5 cm below the level of the inguinal ligament where the femoral artery is best palpated, without applying any pressure that may affect the FV diameter.

Left Lateral Tilt Position; Supine Position

Eligibility Criteria

• Age: 18 Years+
• Sex: female
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• ASA 2
• Uncomplicated pregnancy
• Height between 150 cm-180 cm
• Signed the informed consent form
• hours of fasting before the operation
• Patients who refuse normal delivery

You may not qualify if:

• Obstetric comorbidities affecting caval compression of the aorta
• Transverse development
• Fetal macrosomia
• Uterine anomaly
• Polyhydramnion
• Oligohydroamnion
• Membrane ruptures
• Intrauterine growth retardation
• Mothers with hyperactive lung disease
• Those with autonomic neuropathy
• Kidney failure
• Smokers
• Severe scoliosis or kyphosis
• Multiple pregnancy (twins, triplets,...)
• Those who do not reach T6 sensory block level after 10 minutes

Sponsors & Collaborators

• Mehmet Sarı: lead

Study Sites (1)

Bezmialem Vakıf Univeristesi Dragos Hastanesi Yalı, Kennedy Cd. No:16.

Istanbul, 34844, Turkey (Türkiye)

Location

Related Publications (2)

• Yao SF, Zhao YH, Zheng J, Qian JY, Zhang C, Xu Z, Xu T. The transverse diameter of right common femoral vein by ultrasound in the supine position for predicting post-spinal hypotension during cesarean delivery. BMC Anesthesiol. 2021 Jan 20;21(1):22. doi: 10.1186/s12871-021-01242-8.

  PMID: 33472587 BACKGROUND

• Lal J, Jain M, Rahul, Singh AK, Bansal T, Vashisth S. Efficacy of inferior vena cava collapsibility index and caval aorta index in predicting the incidence of hypotension after spinal anaesthesia- A prospective, blinded, observational study. Indian J Anaesth. 2023 Jun;67(6):523-529. doi: 10.4103/ija.ija_890_22. Epub 2023 Jun 14.

  PMID: 37476444 BACKGROUND

MeSH Terms

Interventions

Supine Position

Intervention Hierarchy (Ancestors)

Posture; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena

Central Study Contacts

MEHMET SARI Dr, Medical Doctor

CONTACT

+095454624611; mehmet.sari@bezmialem.edu.tr

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: In this clinical trial, besides the anesthesiologist performing the ultrasonography (USG), the following parties will be masked: Outcome Assessor(s): The individuals responsible for measuring the post-spinal hypotension outcomes, such as blood pressure and heart rate, will be blinded to the patient's assigned position (supine or left lateral tilt). This ensures that their measurements and assessments are not influenced by the positioning during the ultrasound evaluation. Data Analysts: The data analysts, who will perform the statistical analysis of the study outcomes, will be blinded to the group assignments (supine or left lateral tilt). This is done to avoid bias in interpreting the results related to the position and its effect on post-spinal hypotension. Patients: The patients themselves will not be aware of the specific position (supine or left lateral tilt) they are assigned to during the ultrasound procedure, as this will be randomized. However, they will be informed of the pro
• Purpose: PREVENTION
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Principal Investigator

Model Details: All ultrasonography (USG) procedures will be performed by the same anesthesiologist using a Ultrasound device before the start of spinal anesthesia (SA) and after baseline blood pressure and heart rate have been measured. Patients will be placed in supine and left lateral tilt (LLT) positions. After at least 3 minutes in each position, ultrasound of the inferior vena cava (IVC) and femoral vein (FV) will be performed. The oblique probe will be placed below the xiphoid. Anteroposterior diameters and peak velocities of the IVC will be measured 2-3 cm below the IVC-right atrium For standardization purposes, measurements of the right femoral vein will be used in the study. The FV will be visualized with B-mode ultrasound 2-5 cm below the level of the inguinal ligament where the femoral artery is best palpated, without applying any pressure that may affect the FV diameter.

Study Record Dates

• First Submitted: March 10, 2025
• First Posted: March 20, 2025
• Study Start: May 1, 2025
• Primary Completion: April 30, 2026
• Study Completion (Estimated): August 31, 2026
• Last Updated: March 20, 2025

Record last verified: 2025-03

Locations

TU (1)