Chronic kidney disease

Chronic kidney disease (CKD)

Most children with CKD are asymptomatic until approaching chronic renal disease stage 4 (see Table 11.7). CKD should be suspected if:

• failure to thrive;
• polyuria and polydipsia;
• lethargy, lack of energy, poor school concentration;
• other abnormalities such as rickets.

CKD: Correcting common misconceptions

• Plasma creatinine can remain normal until GFR is reduced to <50%.
• The urine flow rate may not mean a good GFR as many children with renal dysplasia have polyuria and nocturia.
• Other urinary abnormalities such as proteinuria, glycosuria can be an indicator of tubular dysfunction.

The focus is on GFR and not plasma creatinine

• GFR can be formally measured by the Iohexol method or alternatively by ⁵¹Cr EDTA or inulin methods clearance,
• In ordinary clinical practice GFR (mL/min/1.73m²) may be estimated (note: less accurate in children <2yrs or >14yrs):

GFR (estimated) = 40 × height (cm)/creatinine (µmol/L).

Investigations

• Urinalysis.
• Blood:

FBC + iron studies if anaemic;

electrolytes/Ca/PO₄/ALP/albumin;

pH/bicarbonate;

parathyroid hormone (PTH).

• Renal tract US.
• Left hand and wrist X-ray for bone age and renal osteodystrophy score.
• ECG/echocardiography for signs of left ventricular hypertrophy if hypertensive.

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Chronic kidney disease (CKD) is a type of kidney disease