NCT07253818

Passive Leg Raising in Term Pregnancy on Hemodynamic Monitoring - Validating With Transthoracic ECHO (LG-ECHO)

Transthoracic Echocardiography as the Reference for Validating Non-invasive Hemodynamic Monitoring During Passive Leg Raising in Term Pregnancy

• Status: Withdrawn
• Phase: —
• Study type: Observational
• Enrollment: 0 (actual)
• Sponsor: Ayse Zeynep Turan Civraz · Other Government
• Sex: Female
• Age: 18 Years – 45 Years
• Healthy volunteers: Accepted

Summary

This prospective observational validation study aims to evaluate the agreement and diagnostic accuracy of ClearSight™ compared with transthoracic echocardiography (TTE) during PLR in term pregnant women. The ultimate goal is to determine whether ClearSight™ can reliably identify preload responsiveness in term pregnant women compared with the echocardiographic gold standard. The clinical implication is that, if validated, ClearSight™ may reduce unnecessary or harmful fluid administration by accurately detecting preload reserve, and improve maternal safety in peripartum care by providing obstetric anesthesiologists with reliable bedside monitoring tools.

Detailed description

Background Pregnancy is characterized by profound hemodynamic changes, which complicate perioperative monitoring and fluid therapy. Non-invasive cardiac output monitoring device, ClearSight™ system, provides continuous stroke volume estimates, but their reliability in pregnant women remains uncertain. Passive leg raising (PLR) is a reversible preload test that can elucidate fluid responsiveness without fluid administration. To date, no study has simultaneously validated ClearSight™ against echocardiographic reference standards during PLR in term pregnant women. Methods This is a prospective, single-centre, method-comparison and diagnostic accuracy study in term pregnant women (≥37 weeks). Simultaneous ClearSight™ and transthoracic echocardiography (TTE) measurements will be obtained at baseline, during PLR, and during recovery. The primary outcome is agreement between ClearSight™-derived stroke volume index (SVI) changes and TTE-derived Left Ventricular Outflow Tract - Velocity Time Integral (LVOT-VTI) changes during PLR. Secondary outcomes include trending ability and diagnostic accuracy of ClearSight™ Δ%SVI for detecting PLR responders. Four-quadrant and polar plot analyses are the parameters for advanced hemodynamic monitoring methods used in echocardiography to assess fluid responsiveness and cardiac output (CO) trending Sample size: 60 participants, providing at least 180 paired observations. Conclusions This study will establish whether ClearSight™ can reliably detect preload responsiveness in term pregnant women. Findings could support safer, real-time, non-invasive hemodynamic management during obstetric anaesthesia and maternal critical care.

Conditions

• Maternity
• Pregnancy
• Labor and Delivery
• Hemodynamic Changes

Interventions

Type	Name	Description
DEVICE	ClearSight™ System	ClearSight™ is FDA 510(k) cleared for non-invasive measurement of blood pressure and derived hemodynamic parameters in adults (≥18 years) and pediatric patients ≥12 years when used with EV1000 or HemoSphere Baseline, during passive leg raising (PLR) and after PLR measurements will be acquired. Data will be continuously recorded for 5 minutes at 60-second intervals using a dedicated monitor (EV1000™).
DEVICE	Transthoracic Echocardiography	This study uses transthoracic echocardiography (TTE), which is a non-invasive imaging modality All measurements will be obtained with participants in the 15° left tilt position in order to minimize inferior vena cava compression from the gravid uterus and to avoid haemodynamic fluctuations associated with positional changes Initially, the left ventricular outflow tract (LVOT) diameter will be obtained at end-expiration in the parasternal long-axis view, measured from the inner edge to inner edge of the aortic annulus. Subsequently, the LVOT velocity-time integral (LVOT-VTI) will be assessed using pulsed-wave Doppler, with the sampling volume positioned at the centre of the LVOT in the apical five-chamber view. LVOT diameter will be measured from the parasternal long-axis view (inner-edge to inner-edge, mid-systole), with the average of two measurements recorded. Measurements will be recorded at three timepoints: baseline at the end of PLR, after PLR
PROCEDURE	Passive Leg Raising (PLR) Maneuver	This manoeuvre acts as a rapid, transient, and reversible "auto-fluid challenge" by mobilizing blood from the venous reservoir of the lower extremities into the central circulation. The resulting temporary increase in preload can augment cardiac output in preload-responsive patients through the Frank-Starling mechanism . An electronically adjustable bed, capable of altering position without requiring active movement from the participant, will be utilized in the study. Baseline hemodynamic recordings will be taken following 5 minutes of rest in supine position with 15° left tilt, and the head of the bed elevated to 45°. Subsequently, the head section of the bed will be swiftly returned to a flat position, while the leg section will be elevated to 45°, thereby achieving passive leg raising. Hemodynamic variables will be measured around 90 seconds after PLR will be compared with baseline values.

Timeline

• Start date: 2026-01-01
• Primary completion: 2026-05-30
• Completion: 2026-07-30
• First posted: 2025-11-28
• Last updated: 2026-01-29

Locations

1 site across 1 country: United States

Regulatory

• FDA-regulated device study