Use of the urine-to-blood carbon dioxide tension gradient as a measurement of impaired distal tubular hydrogen ion secretion among neonates.
To evaluate the utility of the urinary-minus-blood partial pressure of carbon dioxide (U-B PCO2) gradient for the diagnosis of distal renal tubular acidosis in neonates, we measured the U-B PCO2 gradient corresponding to different urinary bicarbonate concentrations in 40 neonates. The U-B PCO2 gradient in these neonates had a significant linear relationship to the urinary bicarbonate concentration. When the urinary bicarbonate concentration was > 10 mmol/L, in all the neonates the U-B PCO2 could be increased above the 20 mm Hg level. We conclude that it is appropriate to determine the U-B PCO2 gradient as an index of distal urinary acidification and that it is a necessary test for diagnosis of distal renal tubular acidosis in neonates.
Lin
J Y
JY
Department of Pediatrics, China Medical College Hospital, Taichung, Taiwan.
Lin
J S
JS
Tsai
C H
CH
D000141:Acidosis, Renal Tubular / Q000175:diagnosis* / Q000378:metabolism; D001639:Bicarbonates / Q000652:urine; D002245:Carbon Dioxide / Q000097:blood* / Q000652:urine*; D003404:Creatinine / Q000652:urine; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007686:Kidney Tubules, Distal / Q000378:metabolism*; D008297:Male; D011522:Protons; D012964:Sodium / Q000652:urine
D001639:Bicarbonates; D011522:Protons; D002245:Carbon Dioxide; D012964:Sodium; D003404:Creatinine