1. Copyright © 2017 American Academy of Pediatrics.
From:
American Academy of Pediatrics Textbook of Pediatric Care, 2nd Edition, 2017
Figure Legend:
This decision tree presumes that nonrenal causes of hyperchloremic metabolic acidosis, such as viral gastroenteritis, have been ruled out. The usual presentation of RTA is either failure to thrive during infancy or growth progress delay in early childhood. This pathway of decision points is intended for the initial evaluation by a primary care provider and is not complete and does not list all the possibilities. After confirming a low rate of NH4+ excretion, the algorithm depicted has two main branch points based on the serum potassium concentration. If the serum K+ is low or normal and a Fanconi syndrome is not found, the pathway then branches between either an isolated HCO3− reclamation defect or a HCO3− regeneration defect. Monogenic causes of an isolated reclamation defect (if a Fanconi syndrome is excluded) are rare. An isolated reclamation defect is more likely to be encountered as a duration-limited defect in low-birth-weight infants with delayed maturity of tubular function. Beyond this decision point, referral to a pediatric kidney disease specialist is appropriate. If hyperkalemia is found and a K+ secretory defect confirmed by TTKG, possibilities include PHA type 1, salt-losing CAH, and PHA type 2 and referral to a pediatric kidney disease specialist or endocrinologist is appropriate. CAH, congenital adrenal hyperplasia; RTA, renal tubular acidosis; PHA, pseudohypoaldosteronism; TTKG, transtubular potassium gradient; (U – B) PCO2, urine minus blood PCO2.
Date of download: 12/31/2017
Copyright © 2017 American Academy of Pediatrics.
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