Circulating sodium in acute meningitis

Background: In acute meningitis hyponatremia is common and traditionally at tributed exclusively to inappropriate water retention. However, the exact m echanisms underlying hyponatremia are unknown. Methods: The files of 300 pe diatric patients with acute bacterial (n = 190) or aseptic (n = 110) mening itides were retrospectively analyzed. Results: The plasma sodium level rang ed from 122 to 148 mmol/l and was low (< 133 mmol/l) in 97 patients. Fluid volume contraction was significantly more pronounced in hyponatremia (media n 6.0.10(-2)) than in normonatremia (median 2.0.10(-2)). The fractional sod ium excretion was less than 1.00.10(-2) in the 26 hyponatremic children wit h this measurement. Conclusion:ln acute meningitis hyponatremia is not excl usively brought about by inappropriate water retention. Copyright (C) 2001 S. KargerAG, Basel.