Venous Excess and Lung Ultrasound During Continuous Kidney Replacement Therapy in Critically Ill Patients (VExLUS-KRT)

Venous Excess and Lung Ultrasound During Continuous Kidney Replacement Therapy in Critically Ill Patients (VExLUS-KRT)

Hemodynamic management of critically ill patients has long been focused on the arterial side of the vasculature by assessing adequate perfusion pressure. However, the venous pressure is also of critical importance. Venous congestion can occur in patients with right ventricular failure, pulmonary hypertension or fluid overload. Fluid overload has harmful effects to end organs causing acute kidney injury (AKI), lung edema, multiorgan dysfunction and death. Vice versa, AKI can aggravate fluid retention and inflammation. The measurement of venous pressure usually relies on central venous pressure (CVP) and inferior vena cava diameter (IVC). However, CVP measurement has been associated with measurement errors and has low accuracy in predicting fluid responsiveness. Moreover, IVC collapsibility or distensibility is a static parameter and is associated with subjective variability.

Multiorgan Point-of-Care ultrasound (POCUS) can enhance the management of AKI by enabling the evaluation of renal structural abnormalities and hemodynamic status . POCUS allows the clinician to assess intravascular and pulmonary fluid overload. It has been shown that POCUS is a good parameter to predict global fluid status of the patient .

Venous Excess Ultrasound (VEXUS) consists of the evaluation of IVC, hepatic vein, portal vein and intrarenal vein flow pattern. Previous studies showed significant correlation between VExUS score with RRT-free days and guide fluid management in critically ill patients with AKI . VExUS is useful in predicting patients at risk to develop AKI post cardiac surgery . Adding modified lung ultrasound score to the VExUS protocol could help clinician to adjust fluid administration and achieve proper fluid balance during continuous kidney replacement therapy (CKRT). However, the role of using combined VExUS and lung ultrasound in the assessment and guidance of fluid management during CKRT is unknown.

Study Overview

• Status: Completed
• Conditions: Acute Kidney Failure Stage 3
• Intervention / Treatment: Diagnostic test: VExUS (venous excess ultrasound); Diagnostic test: modified VExUS (modified venous excess ultrasound)

Detailed Description

Lung and cardiac ultrasonography can augment the definite diagnosis of volume overload. Thoracic ultrasound demonstrating B-lines which suggest thickened interstitial or fluid filled alveoli or increased vena cava diameter by ultrasound can also be used to assess volume status.

Recently, the venous excess ultrasound grading system (VExUS) has been introduced to be used in conjunction with POCUS to assess significant congestion. This technique used to classify the level of venous congestion by assessing the abdominal blood flow, including hepatic veins (HVs), portal veins (PVs) and intrarenal veins (IRVs). Abnormal patterns of flow in these organs can enhance the clinical evaluation of venous congestion in addition to Inferior vena cava (IVC) ultrasound since organ dysfunction occurring with venous congestion can also be from the transmission of pressure from right atrium (right atrial pressure, RAP) to the peripheral organ. Venous congestion is classified into four grades , ranging from grade 0 (no congestion) to the most severe form, grade 3 (severe congestion) or VExUS "A" through "E".

In the Modified VExUS score, the VExUS grade 0 by IVC cut-off by ≤ 2 cm is replaced with the IVC distensibility index < 18% or the IVC collapsibility index < 50%, depending on patient passive or active ventilation, respectively.

Lung ultrasound and AKI Volume overload is associated with interstitial edema which increases the diffusion distance for oxygen and induces an increase in interstitial fluid pressure, impairing capillary blood flow and exacerbating organ dysfunction . A prospective pilot observational study with 45 adult patients with AKI at any time during ICU stay employed the FALLS (Fluid Administration Limited by Lung Ultrasound) protocol in which they use the LUS for assessing volume status. A new onset of the B-lines was considered as the endpoint of fluid administration. The study demonstrated a linear correlation between baseline B-line scores and PaO2/FiO2 ratio in ICU patients VExUS and lung ultrasound during CKRT

Previous studies have shown that VExUS and lung ultrasound may play a role in predicting AKI severity and may aid fluid de-escalation in critically ill patients. However, no studies have evaluated the role of both VExUS, modified VExUS and lung ultrasound in guiding fluid management during CKRT. Our research aims to evaluate the prevalence of venous congestion by VExUS, mVExUS and lung ultrasound during CKRT and its association with clinical outcomes.

• Study Type: Observational
• Enrollment (Actual): 100

Contacts and Locations

Study Locations

• Thailand
  • Bangkok
    • Bangkok, Bangkok, Thailand, 10330
      • King chula memorial hospital

Participation Criteria

Eligibility Criteria

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

• Sampling Method: Non-Probability Sample

Study Population

patients without ESRD that initiate CKRT

Description

Inclusion Criteria:

1. Adults (≥ 18 years of age)
2. Admitted to ICU
3. Plan to initiate CKRT by clinician's judgement

Exclusion Criteria:

1. Refuse to participate
2. Previous diagnosis of end-stage kidney disease (ESKD) currently on kidney replacement therapy
3. Kidney tran splant recipient
4. Receive KRT before ICU admission
5. Structural kidney diseases which will interfere with intrarenal doppler ultrasound e.g. renal artery stenosis, autosomal dominant polycystic kidney disease etc.
6. Patients with previously known conditions that interfere with portal doppler assessment, namely liver cirrhosis, severe tricuspid regurgitation with structural heart disease or massive ascites.
7. Underlying disease process with a life expectancy less than 90 days
8. Pregnancy
9. Concomitant severe respiratory distress syndrome
10. Expected life expectancy <48 hours
11. Receiving extracorporeal membrane oxygenation (ECMO)

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort

Intervention / Treatment

Patients receiving CKRT; Adults (≥ 18 years of age); Admitted to ICU; Plan to initiate CKRT by clinician's judgement

Diagnostic test: VExUS (venous excess ultrasound); IVC, hepatic veins (HVs), portal veins (PVs) and intrarenal veins (IRVs), and lung ultrasound; Other Names: Bioelectrical impedence (BIA); N-terminal pro B-type natriuretic peptide (NT-proBNP); modifiedVExUS; Diagnostic test: modified VExUS (modified venous excess ultrasound); replace the IVC maximal diameter cut-off by ≤ 2 cm with the IVC distensibility index < 18% or the IVC collapsibility index < 50%, depending on patient passive or active ventilation, respectively.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
To assess the prevalence of venous congestion by using VExLUS and modifiedVExUS in patients who receive CKRT	prevalence of venous congestion	1 day

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
to evaluate inter-observer variability in determining VExLUS	inter-observer variability	3 days
To evaluate the association between VExLUS and modifiedVExUS scores and all-cause mortality within 90 days, KRT-free days, ventilator-free days, vasopressor-free days, ICU-free days, dialysis dependence ay 28 days and 90 days	clinical outcomes	up to 90 days
- to assess the correlation of VExLUS and modifiedVExUS score with bioelectrical impedance vector analysis (BIVA) parameters and biomarkers	Correlation to BIVA	1 day
To evaluate the association between VExLUS and modifiedVExUS scores and all-cause mortality within 28 days	28 days all cause mortality	28 days
Association between protein-calorie malnutrition and mortality in patients with acute kidney injury (AKI) undergoing continuous renal replacement therapy (CRRT).	To determine the association between protein-calorie malnutrition and mortality in patients with acute kidney injury (AKI) undergoing continuous renal replacement therapy (CRRT).	7 days after enrollment
optimal protein and energy supplementation and mortality	To identify the optimal amount of protein and energy supplementation required to reduce mortality.	From enrollment to the end of treatment at 28 days
Maximum level of protein and energy intake association with clinical outcomes	To determine the maximum levels of protein and energy intake associated with the best clinical outcomes.	from enrollment upto 28 days
Current prescribed protein and energy in AKI patients during CRRT	To find the current prescribed protein and energy practice in AKI patients during CRRT?	from enrollment date to 7 days after enrollment
association between energy intake, protein intake and nPCR in AKI patients during CRRT	To find association between energy intake, protein intake and nPCR in AKI patients during CRRT with clinical outcomes.	from enrollment to 7 days after enrollment
correlation between protein intake and nPCR	To find the correlation between prescribed protein intake and nPCR?	from enrollment to 7 days after enrollment

Collaborators and Investigators

• Sponsor: Chulalongkorn University

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2024
• Primary Completion (Actual): November 20, 2025
• Study Completion (Actual): November 30, 2025

Study Registration Dates

• First Submitted: January 28, 2024
• First Submitted That Met QC Criteria: February 4, 2024
• First Posted (Actual): February 12, 2024

Study Record Updates

• Last Update Posted (Actual): May 8, 2026
• Last Update Submitted That Met QC Criteria: May 5, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Acute kidney injury; Critically ill; POCUS; Continuous kidney replacement therapy; VexLUS; Kidney replacement therapy; modifiedVExUS
• Additional Relevant MeSH Terms: Urogenital Diseases; Pathologic Processes; Male Urogenital Diseases; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Disease Attributes; Renal Insufficiency; Pathological Conditions, Signs and Symptoms; Critical Illness; Acute Kidney Injury; Physiological Effects of Drugs; Natriuretic Agents; Natriuretic Peptide, Brain
• Other Study ID Numbers: 0899/66

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No