Hypokalemia complicating emergency fluid resuscitation in children

Our clinical observations suggested that vigorous fluid therapy in children often resulted in hypokalemia. A retrospective review was conducted of four years of admissions to a pediatric intensive care unit. A total of 29 patients were identified who received at least 20 ml/kg of intravenous fluid in their first hour of care and had a pretreatment and posthydration serum K obtained. The potassium levels dropped from a mean pretreatment value of 4.6 +/- 1.0 mEq/L to a mean of 3.3 +/- 0.8 mEq/L (P less than 0.005). Coincidental arterial pH measurements were available in 16 cases. A separate analysis of potassium change in this group revealed that pH change alone could not account for the drop in serum K. Significant hypokalemia may occur after aggressive rehydration of critically ill pediatric patients.