Primary proximal renal tubular acidosis. A therapeutical approach and long term followup

This paper reports a case of proximal renal tubular acidosis followed during 4 years, in a 4 year old girl. High doses of alkali could not be administered owing to gastric intolerance of the patient; diuretic therapy carries the risk of causing severe dehydration or hypotension. The authors administered such a dose of NaHCO₃ to obtain a normal blood pH, with persistent hyperventilation, subnormal bicarbonatemia, and acid urine. This treatment could cause an improvement of rickets, growth and laboratory data. At present, the biochemical data, including urinary excretion of bicarbonate with normal bicarbonatemia, are normal; this indicates a spontaneous recovery of the syndrome. The authors think that low doses of alkali are useful in the transient form of proximal renal tubular acidosis to prevent bone lesion and failure to thrive. But even in the irreversible form of this syndrome, when high alkali doses and diuretics cause dangerous effects, this therapy may be useful to treat some symptoms.