Primary proximal renal tubular acidosis; A therapeutical approach and long term follow-up.
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. We 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. We think that low doses of alkali are useful in the transient form of proximal renal tubular acidosis to prevent bone lesions 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.