NITROGEN-BALANCE IN EXTREMELY LOW-BIRTH-WEIGHT INFANTS WITH NONOLIGURIC HYPERKALEMIA

We measured nitrogen balance and urinary 3-methylhistidine molar ratio s in 33 extremely low birth weight infants (12 with hyperkalemia and 2 1 without) for the first 3 days of life. Although all infants were in negative nitrogen balance during the study, there was no difference in the degree of negative nitrogen balance between the two groups. There was also no difference in the 3-methylhlstidine/creatinine molar rati os, indicating that muscle protein catabolism did not differ. We concl ude that it is unlikely that catabolism contributes to the development of nonoliguric hyperkalemia in extremely low birth weight infants.