Usefulness of Bedside Emergency Ultrasound for Detecting Significant Dehydration in Children

ABSTRACT

PURPOSE: Using bedside emergency ultrasonography (EUS), measurement of the ratio of inferior vena cava (IVC) to abdominal aorta (Ao) diameter may be useful in objectively assessing children with dehydration. The objectives of this study were (1) to analyze the predictability of the ratio of IVC to Ao diameters (IVC/Ao) in dehydrated children and (2) to determine which measurement method would be best to detect significant dehydration in children. METHODS: This prospective observational study was performed in an urban emergency department. Children between 6 months and 6 years of age with clinical suspicion of dehydration and who were admitted to the hospital were enrolled. Using bedside EUS, measurement of IVC and Ao diameters and body weight check were done before IV hydration. We followed up on their body weight during hospitalization. Dividing subjects into (1) a moderate and severely dehydrated group, which was defined as weight change more than 5% during hospitalization, and (2) a non-dehydrated group, we compared the IVC/Ao ratios of the two groups. RESULTS: A total of 59 patients were enrolled. There were significant differences between dehydrated and nondehydrated groups in IVC/Ao on longitudinal views and in the major diameter of IVC/Ao on transverse views (p=0.010 and <0.01, respectively). Its area under the curve in ROC analysis was 0.69 and 0.81, respectively. The cut-off value for the major diameter of IVC/Ao was 0.879 with 85% sensitivity and 79.9% specificity. Laboratory tests such as the BUN/Cr ratio, total CO2, and bicarbonate didn't show any differences between the two groups. CONCLUSION: The IVC/Ao ratio measured in transverse views by bedside EUS could help the emergency physician identify significant dehydration in clinically suspected pediatric patients.