Triage considerations Patients with CKD may present in extremis due to fluid or electrolyte imbalances Cardiopulmonary function may be severely compromised due to volume excess Patients may demonstrate lifethreatening dysrhythmias due to electrolyte disturbances Altered mental status may be secondary to azotemia, electrolyte, or acid–base abnormalities Triage will depend on the patient’s clinical status at the time of presentation Clinical assessment Though many children with CKD who present for emergent care have a known history of renal disease, some will present with previous unknown CKD For those with a new diagnosis, the physician should inquire about previous episodes of urinary tract infections as well as signs of concentrating defects or urologic disease, such as polyuria, polydipsia, and enuresis To evaluate for signs consistent with chronic glomerulonephritis, history of gross hematuria, edema, rashes, or evidence of systemic inflammation should be sought A review of family history should include inquiries of urologic disease, vesicoureteral reflux, progressive kidney disease, cystic kidney disease, and early-onset hypertension The physical evaluation of a child with CKD must include accurate assessment of blood pressure, cardiopulmonary examination, volume status, and growth parameters Initial laboratory studies should be guided by the presenting complaint and history, though assessment of blood counts, electrolytes (including calcium and phosphorus), acid–base status, and renal function should be performed The GFR may be estimated by using the Schwartz formula ( Table 100.13 ), which takes into account the serum creatinine and the patient’s height and gender However, it must be acknowledged that this formula overestimates GFR especially at levels of decreased function Urinalysis should also be performed Most patients with congenital dysplasia or reflux nephropathy will have bland urine sediments and modest amounts of proteinuria Significant hematuria, heavy proteinuria, and active urine sediment with glomerular hematuria and cellular casts would be consistent with glomerular disease Further laboratory studies should be guided by the presentation of illness and clinical suspicion For all children with newly diagnosed CKD of unknown etiology and for many children with known urologic disease, a renal ultrasound is indicated