RESUMEN
OBJECTIVES: Urine anion gap(UAG) and urine osmolal gap(UOG) were proposed as indirect measures of urine ammonium(NF4+). While the former is known to have its usefulness limited to hyperchloremic metabolic acidosis, the latter is reported to have its correlation with urine NE4+ in ketoacidosis. This study was undertaken to evaluate the correlation of urine NH with IJOG in high anion gap metabolic acidosis(AGMA) and to compare it with UAG. METHODS: We measured urine NH' by enzymatic determination, UOG(=0.5 X [urine osmolality-{2 X (Na++K+)+urea+glucose)]), and UAG(=Na++K+-Cl-) in 18 patients(serum AG=24.4+/-1.6mmol/L ) with AGMA. RESULTS: When they were grouped into those with acute disorders(n=11) and those with chronic disorder(n=7), urine Nk4+ concentration was higher (p40mmol/d) had the UOG>40mmol/L. CONCLUSION: In contrast to the UAG, the UOG has a significant correlation with urine NH4+ in AGMA.