Fluid management of hypernatraemic dehydration to prevent cerebral oedema: a retrospective case control study of 97 children in China.

AIM: To compare the fluid management of hypernatraemic dehydration in acute gastroenteritis in those who developed cerebral oedema (cases) versus those who did not (controls).

METHODS

A retrospective study of 97 cases of hypernatraemic dehydration at a tertiary children's hospital in China over five years, in which rehydration regimes of 49 children who developed cerebral oedema were compared with 48 children who made an uneventful recovery.

RESULTS

Risk factors for cerebral oedema (vs. no cerebral oedema) were an initial fluid bolus (29/49 vs. 15/48, P=0.006), the mean rate of bolus infusion (14.7+/-2.2 vs. 10.8+/-1.4 mL/kg/hr, P<0.001), the severity of hypernatraemia (serum sodium 167.7+/-7.8 vs. 161.3+/-7.9 mmol/L, P<0.001) and the overall rehydration rate (8.2+/-1.1 vs. 6.4+/-0.6 mL/kg/hr, P<0.001). On logistic regression, a rapid rehydration rate was the most significant contributor to cerebral oedema. From receive operating characteristic (ROC) curve analysis, the safe rate of rehydration was <6.8 mL/kg/hr.

CONCLUSION

The key risk factors for the development of cerebral oedema during recovery from hypernatraemic dehydration were too rapid a rate of rehydration, an initial fluid bolus to rapidly expand plasma volume and the severity of the hypernatraemia. Thus, we conclude that a uniformly slow rate of rehydration is the best way of preventing cerebral oedema.