Correlation Between Biodemographic Parameters and the Size of Inferior Vena Cava and Collapsibility Index Using Ultrasound in Children

There is a concern regarding the relationship between biodemographic parameters at different ages and the size of inferior vena cava (IVC) and the collapsibility index (CI). Due to the lack of normative data on these parameters in children, we aimed to use ultrasound to determine the mean sizes of IVC in healthy children and calculate the CI.

In this analytical cross-sectional study, we measured the IVC diameter in euvolemic children aged four weeks to 12 years. The maximum IVC diameter was recorded during the exhalation phase of the respiratory cycle, while the minimum diameter was recorded during the inhalation phase using M-mode. Additionally, we calculated the CI by dividing the difference between the maximum and minimum IVC diameters by the maximum diameter.

In this study, 534 euvolemic healthy children with a mean age of 6.77±3.22 years were assessed. The mean diameter of the maximum IVC during exhalation was 5.26±4.70 and the mean diameter of the minimum IVC during inspiration was 2.96±2.89 mm. The mean CI in the present study was 0.5±0.13. Ultrasound measurements of IVC diameter during exhalation, unlike IVC diameter during inhalation, were positively correlated with age, weight, and height. The mean IVC and CI had a direct and significant correlation with biodemographic parameters, such as age, height, weight, and body mass index.

Evaluating intravascular volume status holds significant clinical relevance, particularly in pediatric patients. Utilizing ultrasound to assess the IVC allows for swift and noninvasive analysis of an individual’s hemodynamics, impacting clinical decision-making positively. Establishing normative IVC measurements in healthy and euvolemic children can serve as valuable reference data for clinicians and help them accurately assess fluid status in unwell pediatric patients.