Evaluation of the Microcirculatory Response to Fluids in Critically Ill Patients With Venous Congestion: A Prospective Observational Study (MICRO-CONGEST)

The hypothesis is that fluid-responsive patients who show signs of venous congestion experience a worsening of microcirculatory status after fluid administration compared to patients without signs of venous congestion

Study Overview

• Status: Recruiting
• Conditions: Microcirculation; Venous Congestion; Volume Expansion
• Intervention / Treatment: Drug: fluid challenge

• Study Type: Observational
• Enrollment (Estimated): 30

Contacts and Locations

Study Locations

• Italy
  • Italy
    • Ancona, Italy, Italy, 60123
      • Recruiting
      • Aou Delle Marche
      • Contact: Abele Donati Pr, PhD; Phone Number: +390715963858; Email: a.donati@univpm.it

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Critically ill patients admitted to the intensive care unit

Description

Inclusion Criteria:

• Critically ill patients admitted to the intensive care unit
• Invasive or minimally invasive hemodynamic monitoring

Exclusion Criteria:

• Suspected or confirmed pregnancy
• Inability to access the oral cavity (e.g., facial trauma, oral bleeding)

Study Plan

How is the study designed?

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Sublingual total vessel density (TVD)	To compare changes in sublingual microcirculatory parameter - total vessel density (TVD) - before fluid administration, immediately after volume expansion, and 30 minutes post-fluid administration in preload-dependent patients with and without signs of venous congestion.	Baseline, immediately post-fluid challenge, and 30 minutes post-fluid challenge

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Sublingual percentage of perfused vessels (PPV)	To compare changes in sublingual microcirculatory parameter - percentage of perfused vessels (PPV) - before fluid administration, immediately after volume expansion, and 30 minutes post-fluid administration in preload-dependent patients with and without signs of venous congestion.	Baseline, immediately post-fluid challenge, and 30 minutes post-fluid challenge
Change in Sublingual Microcirculatory Flow Index (MFI)	The primary objective of the study is to compare changes in sublingual microcirculation, measured by the Microcirculatory Flow Index (MFI), before fluid administration, immediately after volume expansion, and 30 minutes post-fluid administration in preload-dependent patients with and without signs of venous congestion.	Baseline, immediately post-fluid challenge, and 30 minutes post-fluid challenge
Change in Sublingual perfused vessel density (PVD)	To compare changes in sublingual microcirculatory parameters - perfused vessel density (PVD) - before fluid administration, immediately after volume expansion, and 30 minutes post-fluid administration in preload-dependent patients with and without signs of venous congestion.	Baseline, immediately post-fluid challenge, and 30 minutes post-fluid challenge
Change in Sublingual microcirculatory heterogeneity index (MHI)	To compare changes in sublingual microcirculatory parameters - microcirculatory heterogeneity index (MHI) - before fluid administration, immediately after volume expansion, and 30 minutes post-fluid administration in preload-dependent patients with and without signs of venous congestion.	Baseline, immediately post-fluid challenge, and 30 minutes post-fluid challenge
Change in Sublingual PPV in Non-Preload-Dependent Patients With and Without Venous Congestion	To compare changes in sublingual PPV before fluid administration, immediately after volume expansion, and 30 minutes post-fluid administration in non-preload-dependent patients with and without signs of venous congestion.	Baseline, immediately post-fluid challenge, and 30 minutes post-fluid challenge
Change in Sublingual TVD in Non-Preload-Dependent Patients With and Without Venous Congestion	To compare changes in sublingual TVD before fluid administration, immediately after volume expansion, and 30 minutes post-fluid administration in non-preload-dependent patients with and without signs of venous congestion.	Baseline, immediately post-fluid challenge, and 30 minutes post-fluid challenge
Change in Sublingual MFI in Non-Preload-Dependent Patients With and Without Venous Congestion	To compare changes in sublingual MFI before fluid administration, immediately after volume expansion, and 30 minutes post-fluid administration in non-preload-dependent patients with and without signs of venous congestion.	Baseline, immediately post-fluid challenge, and 30 minutes post-fluid challenge
Change in Sublingual PVD in Non-Preload-Dependent Patients With and Without Venous Congestion	To compare changes in sublingual PVD before fluid administration, immediately after volume expansion, and 30 minutes post-fluid administration in non-preload-dependent patients with and without signs of venous congestion.	Baseline, immediately post-fluid challenge, and 30 minutes post-fluid challenge
Change in Sublingual MHI in Non-Preload-Dependent Patients With and Without Venous Congestion	To compare changes in sublingual MHI before fluid administration, immediately after volume expansion, and 30 minutes post-fluid administration in non-preload-dependent patients with and without signs of venous congestion.	Baseline, immediately post-fluid challenge, and 30 minutes post-fluid challenge
Association Between Venous Congestion and TVD in Critically Ill Patients and Subpopulations	o evaluate the relationship between signs of venous congestion TVD at baseline, after fluid administration, and 30 minutes post-fluid administration in critically ill patients and subgroups (e.g., septic shock).	Baseline, immediately post-fluid challenge, and 30 minutes post-fluid challenge
Association Between Venous Congestion and PVD in Critically Ill Patients and Subpopulations	To evaluate the relationship between signs of venous congestion and PVD at baseline, after fluid administration, and 30 minutes post-fluid administration in critically ill patients and subgroups (e.g., septic shock).	Baseline, immediately post-fluid challenge, and 30 minutes post-fluid challenge
Association Between Venous Congestion and MFI in Critically Ill Patients and Subpopulations	To evaluate the relationship between signs of venous congestion and MFI at baseline, after fluid administration, and 30 minutes post-fluid administration in critically ill patients and subgroups (e.g., septic shock).	Baseline, immediately post-fluid challenge, and 30 minutes post-fluid challenge
Association Between Venous Congestion and PPV in Critically Ill Patients and Subpopulations	To evaluate the relationship between signs of venous congestion and PPV at baseline, after fluid administration, and 30 minutes post-fluid administration in critically ill patients and subgroups (e.g., septic shock).	Baseline, immediately post-fluid challenge, and 30 minutes post-fluid challenge
Association Between Venous Congestion and MHI in Critically Ill Patients and Subpopulations	To evaluate the relationship between signs of venous congestion and MHI at baseline, after fluid administration, and 30 minutes post-fluid administration in critically ill patients and subgroups (e.g., septic shock).	Baseline, immediately post-fluid challenge, and 30 minutes post-fluid challenge
Association Between Venous Congestion and TVD at Baseline	To evaluate the association between signs of venous congestion and TVD at baseline in critically ill patients and subgroups (e.g., septic shock).	Baseline
Association Between Venous Congestion and PVD at Baseline	To evaluate the association between signs of venous congestion and PVD at baseline in critically ill patients and subgroups (e.g., septic shock).	Baseline
Association Between Venous Congestion and MFI at Baseline	To evaluate the association between signs of venous congestion and MFI at baseline in critically ill patients and subgroups (e.g., septic shock).	Baseline
Association Between Venous Congestion and PPV at Baseline	To evaluate the association between signs of venous congestion and PPV at baseline in critically ill patients and subgroups (e.g., septic shock).	Baseline
Association Between Venous Congestion and MHI at Baseline	To evaluate the association between signs of venous congestion and MHI at baseline in critically ill patients and subgroups (e.g., septic shock).	Baseline

Collaborators and Investigators

• Sponsor: Università Politecnica delle Marche
• Collaborators: Università Politecnica delle Marche, Ospedali riuniti di Ancona

Study record dates

Study Major Dates

• Study Start (Actual): December 15, 2024
• Primary Completion (Estimated): June 1, 2026
• Study Completion (Estimated): June 1, 2026

Study Registration Dates

• First Submitted: April 18, 2025
• First Submitted That Met QC Criteria: March 23, 2026
• First Posted (Actual): March 30, 2026

Study Record Updates

• Last Update Posted (Actual): April 2, 2026
• Last Update Submitted That Met QC Criteria: March 28, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Hyperemia
• Other Study ID Numbers: Prot. 2024 213

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No