A 10-year-old girl presented with two weeks of progressive vision loss. She was seen as an outpatient by a retinal specialist, who referred her to the ED with the image shown.
The patient denied any complaints beyond vision loss. Her mother said the patient appeared puffy and had swelling around her eyes, which they had noted earlier that day. No other complaints such as chest pain, shortness of breath, or weight change were reported.
The patient was comfortable in bed with initial vital signs documented as a blood pressure of 211/131 mm Hg, a heart rate of 98 bpm, a temperature of 98.1°F, and a normal respiratory rate and pulse oxygenation. The patient was 80.2 kg. Her physical exam was unremarkable except for periorbital edema and nonpitting edema of her bilateral upper and lower extremities. Her lungs were clear, and no unusual bruising or palpable liver was found.
A peripheral IV was started, and a variety of labs were drawn. Repeat systolic blood pressure readings remained 220-240 mm Hg. Immediate blood pressure control was initiated for a hypertensive emergency with a nitroglycerin drip titrated to SBP 180s. Initial labs returned with a hemoglobin and hematocrit of 8.9 and 26.2, respectively, bicarb of 20, creatinine of 2.15 with BUN 17, and normal sodium. Protein, albumin, and calcium were 4.9 g/dL, 2.1 g/dL, and 7.4 mg/dL, respectively. The patient was admitted to the pediatric ICU for further care. What is going on with this child?
Find the diagnosis and case discussion on p. 24.
Diagnosis: Nephrotic Syndrome
The patient's constellation of hypertension and initial laboratory values were concerning for nephrotic syndrome. A diagnosis of hypertensive emergency was made given the evidence of end-organ damage on her retinas, kidneys, and low serum protein.
Nephrotic syndrome is the most commonly acquired renal disease in children. It affects children of all ages, including infants, but is most common among school-aged children and adolescents. The prevalence is 16 per 100,000 (Pediatr Rev 2015;36:117) with a 2:1 male:female predominance. (Rosen's Emergency Medicine: Concepts and Clinical Practice. Philadelphia: Elsevier; 2018.)
Nephrotic syndrome is characterized by a disruption of the filtration system in the glomeruli of the kidney, leading to proteinuria. This abnormality is best visualized using an electron microscope, but may appear normal through light microscopy. The most common cause of primary nephrotic syndrome in school-aged patients is minimal change disease, which is often only seen using an electron microscope. (Pediatr Rev 2015;36:117.)
Nephrotic syndrome can present in a variety of ways. Some children are noted to have elevated protein in random sampling of urine or a urine protein:creatinine higher than 2,000 mg/g. Others may present with dependent edema or periorbital edema. The disease often presents following a recent illness. Other notable lab abnormalities may include hyperlipidemia, hypertriglyceridemia, and low serum calcium (related to low albumin).
Workup of nephrotic syndrome should include a urinalysis, spot urine, creatinine ratio, and complete metabolic and lipid panels. Investigation of the underlying cause may include extensive rheumatologic workup, infectious disease evaluation, renal biopsy if over age 12, and advanced imaging. (Pediatrics 2009;124:747.) Genetic testing or counseling may be needed depending on the age of onset because infantile onset is often inherited. The diagnosis can be made based on urine protein: a creatinine ratio ≥2 or a serum albumin ≤2.5. (Pediatrics 2009;124:747; Pediatr Rev 2015;36:117.)
Complications related to nephrotic syndrome include infection due to the loss of immunoglobulins and induced immunocompromised state. Encapsulated organisms including Streptococcus pneumonia and Haemophilus influenzae are prevalent, and re-vaccination is necessary, including 23-valent pneumococcal polysaccharide vaccine (PPV23) for children over age 2. Spontaneous bacterial peritonitis is common because of the immunocompromised state. Thrombotic events are also known complications affecting two percent of patients. (Rosen's Emergency Medicine, 2018.) This is due to volume depletion and upregulation of procoagulants by the liver. Lastly, hypovolemia can lead to acute renal insufficiency, which usually improves with volume repletion.
Steroids are the mainstay of initial treatment for nephrotic syndrome, dating back to a trial that ran from 1967 to 1974. Recommended treatment is 2 mg/kg/d (maximum 60 mg) for six weeks, followed by an additional six weeks of 1.5 mg/kg/d (maximum 40 mg) every other day. Families must monitor for signs and symptoms of relapse with frequent urine protein checks and edema checks. Relapse is not uncommon, and some children ultimately require immunomodulators to control their disease. (Pediatrics 2009;124:747; Pediatr Rev 2015;36:117.)
Initial treatment should include emergent stabilization as needed, including aggressive fluid resuscitation for sepsis or hypovolemia. Aggressive blood pressure control was begun with titratable IV medications in our patient's case. These were transitioned gradually to oral medications over the course of seven days for difficult-to-control hypertension. This patient was found to have IgA nephropathy leading to nephrotic syndrome, which was additionally managed with pulsed steroids IV for three days, and then transitioned to oral steroids with treatment to be continued as an outpatient. Lasix and albumin were used to attempt to treat her edema with limited success. She was discharged home on a salt-restrictive diet and fluid restriction.
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