Inferior Vena Cava Collapsibility Index: A Precise Non-invasive Tool for Evaluation of Edema in Children with Nephrotic Syndrome.

Abstract Evaluating the volume status in children with Idiopathic nephrotic syndrome (INS) is mandatory to guide treatment and avoid unnecessary possibly hazardous albumin use. This study aimed to evaluate and compare the available tools used for volume status assessment and differentiating type of edema in children with INS. Sixty children with active INS were included and subdivided into hypovolemic and non-hypovolemic groups based on fractional excretion of sodium (FeNa%) and clinical assessment. All patients were studied for Inferior vena cava collapsibility index (IVCCI), plasma atrial natriuretic peptide (ANP) concentration and Body composition monitor (BCM). Forty-four patients (77.3%) had non-hypovolemic and 16 (26.7%) had hypovolemic states. Plasma ANP levels didn’t differ between hypovolemic and non-hypovolemic subgroups. IVCCI was higher in hypovolemic group (p<0.001) with sensitivity 87.5% and specificity 81.8% for hypovolemia detection while BCM-over hydration (BCM-OH) values were higher in non-hypovolemic group (p=0.04) with sensitivity= 68.2% and specificity =75% for detection of hypervolemia. FeNa% showed negative significant correlation with IVCCI (r= -0.578, p <0.001) and positive significant correlation with BCM-OH (r= 0.33, p=0.018), while FeNa% showed non-significant correlation to plasma ANP concentration (p=0.25). Conclusion: Non-hypovolemic edema is more frequent in edematous INS children than hypovolemic states. IVCCI is a reliable non-invasive bedside tool for evaluating volume status in INS children and is superior to BCM while plasma ANP levels can’t discriminate type of edema in INS.