Sir.—Padilla and colleagues1 recently reported that urine vasopressin concentrations fell during the first 3 days of treatment of bacterial meningitis when patients received maintenance fluid requirements containing a mean of 5.6 mEq/kg per day of ionized sodium. In a similar series of patients,2 plasma arginine vasopressin normalized within 24 hours when maintenance plus replacement fluids (the mean volume of fluid administered in a 24-hour period was 1.5 × maintenance and contained 7.8 mEq/kg per day of ionized sodium) were given, but remained elevated when fluids were restricted (the mean volume of fluid administered in a 24-hour period was 0.63 × maintenance and contained 2.2 mEq/kg per day of ionized sodium). The data presented by Padilla et al1 appear to corroborate the earlier study,2 but their article does not address the temporal relationship between changes in plasma arginine vasopressin concentration and changes in urine vasopressin concentrations.
POWELL KR, MILLER ME. Fluid Management and Arginine Vasopressin in Bacterial Meningitis. Am J Dis Child. 1992;146(5):540-541. doi:10.1001/archpedi.1992.02160170020006