Portal and Splenic Venous Pulsatility in Postoperative Critically Ill Patients (PULSE-ICU)

Systemic venous congestion is increasingly recognized as an important pathophysiological factor in critically ill patients, particularly after major surgery. The Venous Excess Ultrasound (VExUS) grading system combines inferior vena cava assessment with Doppler evaluation of hepatic, portal, and renal venous flow patterns to identify clinically relevant venous congestion.

The portal venous pulsatility index (PI), calculated using pulsed-wave Doppler measurements at the hepatic hilum, has been described as a marker of venous congestion and has shown potential clinical relevance in the assessment of fluid status and decongestion response.

However, splenic venous pulsatility has not been systematically evaluated as a marker of venous congestion in critically ill patients, and its relationship with portal venous pulsatility remains unknown. Since both venous territories drain into the portal system and may reflect retrograde transmission of elevated right atrial pressure, splenic venous pulsatility could represent an additional non-invasive parameter for congestion assessment.

This prospective, observational, single-center study will investigate the correlation between portal and splenic venous pulsatility measured by Doppler ultrasound in postoperative critically ill patients. Secondary objectives include assessment of measurement reproducibility, evaluation of the relationship with VExUS grading, analysis in clinically relevant subgroups, and exploration of the association between splenic venous pulsatility and decongestion during ICU admission.

No experimental treatment will be administered, and all ultrasound assessments will be performed as an additional non-invasive evaluation alongside standard clinical management.