If the etiology of the renal failure is not known some effort should be made to assess the cause.

The cause of renal failure may determine the best mode of renal replacement therapy and the preparation of the child for renal replacement therapy. If the child has posterior urethral valves, the valves must be ablated prior to a kidney transplant and the bladder might need to be augmented. A combined kidney-liver transplant might be best for the child with congenital oxalosis.

A renal ultrasound is usually the best way to determine renal size, the presence of obstruction, and any evidence of renal parenchymal disease.

A kidney which is dense and exhibits loss of corticomedullary demarcation is typical of renal parenchymal disease. Autosomal dominate and recessive polycystic kidney disease have very characteristic renal findings. In autosomal dominate polycystic (ADPKD) disease the multiple cysts may not be seen in children. However, if one sees several cysts on a child’s renal ultrasound, ADPKD should be suspected. Autosomal recessive polycystic kidneys are large with loss of corticomedullary differentiation. There are tiny cysts intermingled with echodense regions giving a “salt-and-pepper” appearance. The liver may also appear dense. Large swollen kidneys likely represent an acute process, e.g. acute post infectious glomerulonephritis, lupus nephritis, rapidly progressive glomerulonephritis.

There are potentially other radiological studies that can be useful.

A voiding cystourethrogram (VCUG) would be important if reflux or posterior urethral valves were suspected. A radionuclear scan could help locate poorly functioning renal tissue. A CT scan of the abdomen can also locate hypoplastic renal tissue.

A renal biopsy is potentially useful to establish a diagnosis if glomerulonephritis is suspected.

However the kidney may be too fibrotic to biopsy and/or too small. An open biopsy is sometimes performed. However if the process is advanced a diagnosis may not be possible. It is of some importance to establish the etiology for chronic renal failure. There are some forms of renal disease which can reoccur in a transplant. Examples would focal sclerosing glomerulonephritis, membranoproliferative glomerulonephritis, and congenital oxalosis.

Calcium/phosphorus product is often useful.

Normal serum calcium and phosphorus levels indicate a rapid loss of renal function of a short duration. Calcium levels will decrease and phosphorus levels increase quickly after a sudden drop in renal function but not immediately. Alkaline phosphatase will also increase as a result of parathyroid stimulation of bone resorption. A parathyroid hormone (PTH) level is useful not only to establish the chronicity of the process, but to establish a base-line for therapy.

Bone films are useful to assess for renal osteodystrophy and for renal rickets.

A bone age is helpful in determining effects of renal failure on skeletal maturation and growth potential. Children with chronic renal failure often have delayed bone ages and hence the potential to grow with improvement in renal function (recovery, renal transplantation). One would want to know the bone age prior to starting growth hormone in a child with renal failure to determine if hormone therapy is suitable. One might not want to start growth hormone in someone with advanced bone age. A bone density study is useful in determining the degree of mineralization in a child with chronic renal failure and to monitor the effects of therapy such as vitamin D, renal transplantation and steroids and bisphosphonate therapy.

Patients with chronic renal failure usually exhibit anemia of chronic disease.

The hematocrit and hemoglobin and below normal. The red cell indices are usual normal. The reticulocyte count is usually low indicating decreased red cell production. Erythropoietin levels are lower than what would be expected with the degree of anemia exhibited. Iron stores are often adequate. However, an iron panel is indicated especially if the patient is to be stared on erythropoietin therapy. Iron stores must be regularly monitored. The iron turn-over rate is increased because on increased RBC production and destruction. Frequently iron must be supplemented either orally or intravenously to maintain hematocrit and hemoglobin levels. If iron stores are low, iron should be started before beginning erythropoietin. Erythropoietin must be given either subcutaneously or intravenously and the administration may be uncomfortable. It is also expensive.

Because of the increased incidence of GERN and delayed gastric empting such studies as barium swallows, gastric empting studies and pH probes may be useful in selected patients.

Early satiety and poor weight gain may be clues as to the presence of these conditions. Substernal pain especially in the recumbent position may be reported in older children.

The growth rates for height, weight and head circumference are very important to determine and follow in child with chronic renal failure.

There is usually a decrease in the rate of weight gain first, followed by a decrease in the rate of height gain and lastly head circumference. A child with long standing chronic renal failure will often be proportionately small. The growth rates of children with chronic renal failure are most noticeably affected during periods of rapid growth such as infancy and adolescence. Catch-up growth is rarely seen unless intervention is instituted, e.g. renal transplantation or growth hormone. The evaluation of nutritional status of the child is essential. A dietary assessment is very useful. Caloric supplementation is often necessary especially during infancy.

Developmental delay may be seen in children with advanced renal failure occurring early in childhood.

Milestones may be delayed as a result of some therapeutic interventions, e.g. peritoneal dialysis may interfere with sitting up or walking. Older children may exhibit problems with acquiring visual motor skills. Hypertension and/or electrolyte abnormalities may cause seizures and encephalopathic symptoms. The EEG usually does not demonstrate classical seizure patterns. Anticonvulsants may not be indicated.

A child with a chronic disease may lack socialization skills due to absences from school and the parents may have a tendency to protect these children.

They may face social isolation and depression. They may exhibit low self esteem over short statue, poor performance in sports and academically. They may be more dependent upon parents and care-givers than other children their age. They may need more supervision of medication taking behaviors than other children their age. Sometimes parents do not appreciate their inability to care for themselves and do not successfully prepare themselves for independence. Therefore, psychological assessment of the patient and the family situation is necessary prior to renal replacement therapy.