Paediatrics: Renal tubular disorders

2021-03-04 12:00 AM

The renal tubules are responsible for the regulation of fluid, acid-base, and electrolyte balance.

Renal tubular disorders

 

The renal tubules are responsible for the regulation of fluid, acid-base, and electrolyte balance. Abnormalities of renal function may occur at any point along the length of the renal tubule system and may lead to a disturbance in the equilibrium of any of the substances handled by it. It is essential to consider these disorders when there are any of the following:

  •  Glycosuria, amino-aciduria, or impaired ability to concentrate or acidify urine shown on urinalysis.
  • Stones or nephrocalcinosis: distal tubular acidosis and oxalosis are major causes.
  •  Polyhydramnios and failure to thrive in a newborn: e.g. Bartter syndrome associated with hypokalaemic alkalosis.
  •  Failure to thrive with rickets: cystinosis is the commonest cause of Fanconi syndrome.
  •  Major rickets with low plasma phosphate levels: familial hypophosphatemic rickets.
  •  Failure to thrive with low urine osmolality: nephrogenic diabetes insipidus.

Renal tubular acidosis

Renal tubular acidosis (RTA) is a state of systemic hyperchloraemia result-ing from impaired urinary acidification. Three types of RTA exist:

  • Proximal type.
  •  Distal type.
  •  Mineralocorticoid deficiency-associated.