Correlation of sonographic inferior vena cava and aorta diameter ratio with dehydration in Nigerian children

Accurate assessment of the degree of dehydration is essential in the management and fluid therapy of dehydrated children. The invasiveness of central venous pressure limits its routine clinical use. Fortunately, some studies have suggested that ultrasonographic measurement of inferior vena cava (IVC) diameter: aorta diameter ratio (IADR) is an objective method of assessing intravascular volume.

To determine the clinical usefulness of ultrasound measurement of IADR in assessment of children with dehydration.

This was a cross-sectional study which compared dehydrated children to age- and sex-matched euvolemic healthy children as controls. The maximum anteroposterior diameter of the abdominal aorta (at peak systole) and maximum IVC diameter (in expiration) were measured.

A total of 120 subjects and 120 controls were evaluated. The mean age was 21.73 ± 20.89 months for subjects and 21.19 ± 22.13 months for control. The mean IADR for children with mild, moderate, and severe dehydration was 0.75 ± 0.07, 0.55 ± 0.07, and 0.33 ± 0.05, respectively. The mean IADR for controls was 0.99 ± 0.06. IADR had an inverse relationship with the degree of dehydration in the subjects. A cut-off point of 0.86, with a sensitivity and specificity of 96.7% in predicting dehydration, was derived, with the sensitivity and specificity increasing with increasing level of dehydration.

IADR is sensitive and specific for assessing moderate and severe dehydration in Nigerian children.