Comparison of PPV and LVOT VTI During Passive Leg Raising to Predict Fluid Responsiveness

NCT07304661 | Not Yet Recruiting

• 1 other identifier: 2025-SAEK-0811
• Study Type: observational
• Target: 48
• Locations: 1 country
• Sites: 1

Brief Summary

Hemodynamic instability remains one of the leading causes of morbidity and mortality among critically ill patients in intensive care units. One major contributor to this instability is intravascular fluid deficit. Although fluid administration is often preferred as an initial intervention, inaccurate estimation of fluid requirements carries significant risks. Inadequate resuscitation may lead to tissue hypoperfusion and organ dysfunction, whereas excessive fluid loading is associated with pulmonary edema, increased intra-abdominal pressure, multi-organ dysfunction, and increased mortality. Consequently, reliable prediction of fluid responsiveness is considered a critical determinant in modern intensive care management. The limited reliability of static parameters in predicting fluid responsiveness and the fact that PPV retains its validity only under specific clinical conditions highlight the need for more effective methods. In recent years, hemodynamic changes assessed during the passive leg raising (PLR) maneuver have gained prominence; particularly, left ventricular outflow tract velocity time integral (LVOT VTI)-based cardiac output measurements have been identified as a strong parameter for predicting fluid responsiveness . Moreover, changes in pulse pressure variation (PPV) during PLR have also been reported as a potential predictor; however, the number of studies prospectively comparing PPV variation and LVOT VTI-based cardiac output change within the same patient population remains limited . Therefore, the proposed study aims to fill this gap in the literature and contribute to fluid management in the intensive care setting. The aim of this study is to compare the performance of PPV variation and LVOT VTI-based cardiac output change after the PLR maneuver in predicting fluid responsiveness among mechanically ventilated critically ill patients, and to determine the diagnostic value of both methods. The findings of the present study are expected to support more reliable decision-making in fluid therapy and provide clinical evidence toward the individualization of fluid management in intensive care practice.

Conditions

Hemodynamic Instability; Hypovolemia; Critical Illness; Pulse Pressure Variation

Keywords

Fluid Responsiveness; Passive Leg Raising; Pulse Pressure Variation; LVOT VTI; Cardiac Output; Echocardiography

Outcome Measures

Primary Outcomes (1)

• Change in Pulse Pressure Variation (Delta PPV)

  Pulse Pressure Variation (PPV) is recorded via invasive arterial monitoring at baseline (T0, semi-sitting) and during the Passive Leg Raising maneuver (T1).

  Baseline (T0) and between 60 seconds after the PLR maneuver.

Secondary Outcomes (4)

• Percentage Change in Cardiac Output (Delta CO)

  Baseline (T0) and between 60 seconds after the PLR maneuver.

• Correlation between Delta PPV and Delta CO

  Baseline (T0) and between 60 seconds after the PLR maneuver.

• Hemodynamic Parameter Changes (MAP, HR)

  Baseline (T0) and between 60 seconds after the PLR maneuver.

• Diagnostic Accuracy (ROC-AUC, Sensitivity, Specificity, Cut-off)

  Baseline (T0) and between 60 seconds after the PLR maneuver.

Study Arms (2)

Fluid Responders

Defined as an increase in LVOT VTI-based Cardiac Output (CO) of ≥ 10% from baseline.

Fluid Non-Responders

Defined as an increase in LVOT VTI-based Cardiac Output (CO) of \< 10% from baseline.

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

The study population consists of adult critically ill patients admitted to the Intensive Care Unit (ICU) who are receiving mechanical ventilation support. Eligible participants are those identified by the intensive care team as having a suspected intravascular fluid deficit, for whom a fluid responsiveness assessment is clinically indicated. The cohort specifically targets patients undergoing the Passive Leg Raising (PLR) maneuver as part of routine standard practice, where invasive arterial monitoring is available to record Pulse Pressure Variation (PPV).

You may qualify if:

• Adult patients aged ≥18 years
• Patients admitted to the intensive care unit receiving mechanical ventilation
• Presence of suspected intravascular fluid deficit (hypotension, negative fluid balance, or clinical signs of peripheral hypoperfusion)
• Patients in sinus rhythm
• Presence of invasive arterial blood pressure monitoring
• Adequate echocardiographic window allowing transthoracic echocardiographic measurement of LVOT VTI
• Patients ventilated with tidal volume ≥8 mL/kg (ideal body weight)
• Hemodynamically stable enough to allow measurement

You may not qualify if:

• Patients under 18 years of age
• Presence of atrial fibrillation or significant arrhythmias such as frequent ventricular or atrial ectopy
• Severe right ventricular dysfunction or significant tricuspid regurgitation
• Advanced aortic valve disease (severe stenosis or severe regurgitation)
• Patients with significant spontaneous breathing effort
• Patients receiving lung-protective low tidal volume ventilation strategy (\<8 mL/kg) due to ARDS
• Inadequate echocardiographic window for LVOT VTI assessment
• Severe hemodynamic instability during measurement (sudden vasopressor escalation or need for resuscitation)
• Patients who refuse to participate or from whom written informed consent cannot be obtained from themselves or a first-degree relative

Sponsors & Collaborators

• Izmir Katip Celebi University: lead

Study Sites (1)

Izmir Katip Celebi University Atatürk Training and Research Hospital İzmir, , Turkey

Izmir, Turkey (Türkiye)

Location

MeSH Terms

Conditions

Hypovolemia; Critical Illness

Condition Hierarchy (Ancestors)

Pathologic Processes; Pathological Conditions, Signs and Symptoms; Disease Attributes

Study Officials

• Murat Aksun

  Izmir Katip Celebi University Atatürk Training and Research Hospital

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Murat Aksun, M.D.

CONTACT

+90 552 363 16 14; murataksun@yahoo.com

Ahmet Salih Tüzen, M.D.

CONTACT

+90 535 391 55 77; astuzen@icloud.com

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Target Duration: 1 Day
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Medical Doctor

Study Record Dates

• First Submitted: December 13, 2025
• First Posted: December 26, 2025
• Study Start: January 1, 2026
• Primary Completion (Estimated): January 1, 2027
• Study Completion (Estimated): June 1, 2027
• Last Updated: December 26, 2025

Record last verified: 2025-12

Locations

TU (1)