Subclinical defects in renal regulation of acid base balance in children with recurrent urinary tract infections.

Abstract

SummaryRenal control of acid base balance has been evaluated in children with recurrent urinary tract infections. For reference a group of normal children has also been studied. The studies were performed before and after a single oral intake of ammonium chloride. The following parameters have been determined: the maximal ammonia excretion and the relationship between blood total CO2 concentration and urine pH. The maximal ammonia excretion was found to be reduced in proportion to the filtration rate. All the patients with low to moderately reduced filtration rates and four of the patients with subnormal to normal filtration rates demanding larger reduction in blood total CO2 concentration than the normal controls before a fall in the urine pH could be observed. This finding was taken as a sign of reduced bicarbonate threshold. It is therefore suggested that the reabsorption of filtered bicarbonate is one of the most vulnerable function of the kidney in recurrent urinary tract infections.