Utility of the Venous Excess Ultrasound (Vexus) Score to Quantify Venous Congestion in Critically Ill Children Using Point of Care Ultrasound

INTRODUCTION: Fluid overload leads to increased morbidity and mortality in paediatric intensive care unit (PICU) patients. One possible underlying mechanism is venous congestion resulting from fluid overload and cardiac dysfunction. Given the absence of dependable peripheral indicators of venous congestion, it is essential to have objective measures to support critical clinical decisions, such as fluid management, diuretic use, and the treatment of acute kidney injury (AKI). Evaluating venous congestion through point-of-care ultrasound (POCUS) is an emerging technique. VEXUS score is recently developed non-invasive bedside tool to assess venous congestion involving different organ system. AIMS AND OBJECTIVES: To quantify venous congestion with the VEXUS scoring system through POCUS and to study the association between VEXUS grades and patient outcome. MATERIALS AND METHODS: This prospective observational study was conducted in tertiary care PICU. All Critically ill children of 1 yrs to 18 yrs old underwent serial ultrasonographic assessment. Venous excess ultrasound score (VEXUS) comprising inferior vena cava, hepatic vein waveform, and portal vein waveform was assessed within 6hr of PICU admission, 24 hrs, 48 hr and 72 hrs. Grading of VEXUS score done at different timepoints. Demographic details laboratory investigation and respiratory and hemodynamic parameters recorded. Organ dysfunction score, occurrence of acute kidney injury, duration of mechanical ventilation, duration of hospital stay, PICU stay and mortality were recorded. To compare the clinical factors between different levels of VEXUS at different time point, Chi-square test or Fisher's exact test was applied for the categorical observations, Oneway ANOVA or Kruskal Wallis test was applied for the continuous measurements. Logistic regression was carried to estimate the Odds of developing AKI based on VEXUS score. P-value was considered significant at 5% level of significance. RESULTS: A total of 182 patients were enrolled for the study. The median [IQR] age was 78 (48-144) months with 62% were males. At 24 hours, 80(44%) children had venous congestion with 81% -VEXUS-1, 15%-VEXUS-2, and 3.7%-VEXUS-3. The grade of venous congestion changed over 72 hours (VEXUS-1:67%, VEXUS-2:17.5%, and VEXUS-3:14.8%). We noted initial low prevalence of venous congestion which was gradually increased over a period of 72 hrs. Patients with VEXUS>2 had significantly higher fluid overload at 24 (3.8% vs 2.8%), 48 (5.5% vs 3.5%), and 72 (6% vs 3%) hrs as compared to VEXUS <2. Similarly, PELOD score (5,5,6), duration of mechanical ventilation (6,6.5,5.5), PICU (7,8,8) and hospital days (17,13,13) were higher in children VEXUS>2 at 24, 48 and 72 hours respectively. We found significant association between VEXUS>2 and AKI (OR 16.9, 95% CI 3.36-85, p value 0.01) at 48 hours. In the exploratory analysis, septic shock patients (68/182) had higher VEXUS score at 24 hrs (61.8%) and 48 hrs(63.5%) hours as compared to children without septic shock 28.1% at 24 hrs and 38.1% at 48hrs ((p-0.001). CONCLUSION: Though the initial prevalence of venous congestion was low, but it rises over time. A VEXUS score of ≥ 2 was associated with acute kidney injury. VEXUS score can help in early detection of venous congestion and guide in deresuscitation.