Clinical assessment The initial assessment of a child with nephrotic syndrome should focus on the adequacy of intravascular volume and perfusion, respiratory status, and evaluation for evidence of complications such as infection There should be a thorough assessment of recent fluid balance, with specific inquiries to diuretic use, urine output, and gastrointestinal losses As some patients with nephritis will have concomitant nephrotic syndrome (secondary nephrotic syndrome), accurate measurement of blood pressure should be documented to screen for associated hypertension Laboratory investigation should include confirmation of nephrotic syndrome, identification of associated electrolyte abnormalities, and an evaluation for possible underlying etiologies, if clinically indicated by evidence of systemic disease A serum albumin of less than 2.5 g/dL is suggestive of nephrotic syndrome A freshly obtained urine sample should confirm heavy proteinuria by dipstick and be inspected for the presence of macroscopic hematuria, which may suggest glomerulonephritis Nephrotic range proteinuria in children is defined as protein excretion greater than 50 mg/kg/day or 40 mg/m2/hr, though this would depend upon a timed 24-hour urine collection, which is prone to inaccuracies and not feasible in the ED Alternatively, a urine protein to creatinine ratio can be obtained on a spot urine sample to quantify the degree of proteinuria A normal ratio is less than 0.5 in children to 24 months and less than 0.2 in older children and adults Generally, a ratio more than to is consistent with nephrotic range proteinuria Idiopathic nephrotic syndrome is typically associated with bland urine sediment Serum electrolytes may reveal hyponatremia secondary to decreased intravascular volume and stimulation of ADH release Hyponatremia in the edematous child does not reflect total body sodium depletion but water excess that is greater than sodium excess Renal function studies may be abnormal and reflect decreased intravascular volume or the underlying renal disease Complete blood cell counts may demonstrate elevated hemoglobin and hematocrit due to hemoconcentration Hyperlipidemia including elevated total serum cholesterol, triglycerides, and total lipids is typical Studies to distinguish the cause of nephrotic syndrome should be considered based on the patient’s presentation Serum complements may identify disorders associated with complement consumption such as