[Effects on natremia of the intravenous hypotonic fluid administration in hospitalized children with acute lower respiratory tract infection].

INTRODUCTION

Because of the risk of developing hyponatremia, intravenous hydratation prescription in children with lower respiratory tract disease (LRTD) is challenging.

OBJECTIVE

To evaluate if intravenous hypotonic fluid administration in children with LRTD leads to hyponatremia.

METHODS

Patients aged 1 month to 18 years, hospitalized for LRTD, requiring intravenous fluids were included. Blood samples to determine sodium levels were obtained before and within the first twenty four hours of fluids administration. A serum sodium decrease >or= 4 mEq/L was considered significative. Student t test and logarithmic regression was used to analyze results (significance level p<0.05).

RESULTS

From 1039 patients hospitalized with LRTD (58 received intravenous fluids), 35 patients met the inclusion criteria. Median age was 3 months (1-60 months), 57.1% were males. Patients received 59.3 +/- 24 ml/h of intravenous fluids, 39.2 +/- 16 ml/h of electrolyte free water and 2 +/- 1.3 mEq/kg of sodium. Serum sodium was 141.2 mEq/l in the initial sample and 139.3 mEq/l in the second one. Mean serum sodium decrease was 1.9 +/- 4.8 mEq/l (IC 95%: 0.2-3.5; p< 0.026). Eleven patients had a sodium decrease >or=4 mEq/l, none showed clinical manifestation of hyponatremia. For each mEq/l of increase in initial natremia the odds of achieving a decrease in serum sodium >or=4 mEq/l increases in 40% (OR=1.39; IC 95%: 1.1-1.8).

CONCLUSION

A significant decrease in initial serum sodium has been observed in 11 of 35 patients. Higher initial serum sodium values increase the odds of a significant decrease.