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Changes in Portal Vein Pulsatility Variability During a Tidal Volume Challenge Can Predict Fluid Tolerance

NCT07131228 · Status: NOT_YET_RECRUITING · Type: OBSERVATIONAL · Enrollment: 60

Last updated 2025-08-20

No results posted yet for this study

Summary

In critically ill patients, appropriate fluid administration is one of the cornerstones of hemodynamic management, as both hypovolemia and fluid overload can negatively impact clinical outcomes.

For years, fluid responsiveness-defined as an increase in cardiac output following volume administration-has guided decision-making in the postoperative ICU. However, fluid responsiveness alone does not guarantee fluid tolerance, which refers to the venous system's ability to accommodate volume without developing venous congestion or adverse effects such as pulmonary edema, renal or hepatic dysfunction.

The tidal volume challenge (TVC)-which consists of a transient increase in tidal volume from 6 to 8 mL/kg-has been shown to predict fluid responsiveness by enhancing the hemodynamic interaction between the heart and lungs during the cardiac cycle, as measured through dynamic arterial indices such as pulse pressure variation (PPV) or stroke volume variation (SVV). However, these indices do not provide information about fluid tolerance or the state of venous congestion.

Doppler ultrasound of the portal vein, specifically the portal pulsatility index (which under normal conditions presents as a continuous waveform due to the damping effects of the hepatic parenchyma and venous compliance), has been proposed as a non-invasive marker of systemic venous congestion. Studies have shown that an increase in the portal pulsatility index following volume loading may indicate the development of venous congestion and, therefore, poor fluid tolerance.

Since the tidal volume challenge transiently increases intrathoracic pressure and allows dynamic evaluation of cardiovascular responses, we propose that this interaction be assessed not only through arterial dynamic indices (which assess responsiveness) but also through changes in venous flow patterns-specifically, variations in portal pulsatility-so that both fluid responsiveness and tolerance can be predicted with the same test.

Conditions

  • Venous Congestion

Sponsors & Collaborators

  • Dr. Negrin University Hospital

    lead OTHER

Eligibility

Min Age
18 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2025-11-01
Primary Completion
2025-11-30
Completion
2026-11-30

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT07131228 on ClinicalTrials.gov