- Edema, hematuria, and oliguria suggest acute glomerulonephritis.
- Children with nephrotic syndrome are usually immunocompromised and at risk for life-threatening infection.
- Patients with hemolytic uremic syndrome are at risk for hypertension and seizures.
- Hemodialysis may be needed for fluid overload in patients with acute renal failure who are refractory to medical management.
Glomerulonephritis is a histopathologic diagnosis acutely associated with clinical findings of hematuria, edema, and hypertension. It commonly follows a pharyngitis caused by group A β-hemolytic Streptococcus in children between 3 and 7 years of age. Patients < 2 years are rarely affected. Timely treatment of pharyngitis does not clearly decrease the incidence of acute glomerulonephritis.
Glomerulonephritis probably results from the deposition of circulating immune complexes in the kidney. These immune complexes are deposited on the basement membrane, reducing glomerular filtration.1
There is usually a preceding streptococcal infection or exposure 1 to 2 weeks before the onset of glomerulonephritis. An interval of less than 4 days may imply that the illness is an exacerbation of preexisting disease rather than an initial attack. Fever, malaise, abdominal pain, and decreased urine output are often noted.
The physical findings reflect the duration of illness. Initial findings may be mild facial or extremity edema only, with a minimal rise in blood pressure. Patients uniformly develop fluid retention and edema and commonly have hematuria (90%), hypertension (60%–70%), and oliguria (80%). Fever, malaise, and abdominal pain are frequently reported. Anuria and renal failure occur in 2% of children. Circulatory congestion, as well as hypertensive encephalopathy, may be noted.
Urinalysis reveals microscopic or gross hematuria. Erythrocyte casts are present in 60% to 85% of hospitalized children. Proteinuria is generally less than 2 g/m2 per 24 hours. Hematuria (Fig. 84–1) and proteinuria (Fig. 84–2) may present independently and require a specific evaluation.2 Leukocyturia and hyaline and granular casts are common.
Evaluation for hematuria. TB, tuberculosis; RBC, red blood cell; BUN, blood urea nitrogen; Ca, calcium; Cr, creatinine; ANA, antinuclear antibody. (With permission from Barkin RM, Rosen P, eds. Emergency Pediatrics: A Guide to Ambulatory Care. 6th ed. St. Louis, MO: Mosby; 2003:269.)
Evaluation for proteinuria. BUN, blood urea nitrogen. (With permission from Barkin RM, Rosen P, eds. Emergency Pediatrics: A Guide to Ambulatory Care. 6th ed. St. Louis, MO: Mosby; 2003:269.)
The fractional excretion of sodium as a reflection of renal function may be reduced (Table 84–1). The blood urea nitrogen (BUN) level is elevated disproportionately to the creatinine level.
Table 84-1. Evaluation of Renal Failure |Favorite Table|Download (.pdf)
Table 84-1. Evaluation of Renal Failure
Ultrasound: can have increased renal density or slight ...