Brain concussion produces transient hypokalemia in children.

Hyperglycemia and hypokalemia caused by catecholamine discharge have been reported to occur in patients after severe head trauma. The aim of this prospective study was to evaluate whether a similar neuroendocrine and metabolic response is found in children after minor head trauma such as brain concussion (Glasgow Coma Scale (GCS) > or = 13). One hundred fifty patients aged 2 to 14 years (average, 6 years) were divided into three groups (n = 50 in each group). Group 1 included patients admitted to the emergency department for brain concussion (Glasgow Coma Scale (GCS) > or = 13); group 2 included patients admitted for fractures of long bones without head injury; and group 3 were control patients electively admitted for hernia repair. All patients had complete physical and neurological examinations. Complete blood count and blood chemistry were obtained on admission. All blood tests were repeated at 6, 12, and 24 hours in patients belonging to group 1. An electrocardiogram was obtained in selected patients and catecholamine levels were measured in some patients. Statistical analysis was performed using analysis of variance (ANOVA). Serum potassium and sodium levels in patients with brain concussion (group 1) were 3.6 +/- 0.6 and 136 +/- 3 mEq/L, respectively and were significantly lower (P < 0.01) than those in patients belonging to group 2, 4 +/- 0.4 and 138 +/- 3, respectively, and the controls (group 3), 4.2 +/- 0.5 and 140 +/- 2, respectively. Serum glucose level was 124 +/- 34 and 118 +/- 32 mg% in groups 1 and 2 and was significantly higher than that of the controls (group 3), 90 +/- 23 mg%. There was no correlation between serum electrolytes and GCS. No electrocardiogram changes or elevation of serum catecholamines were found. Hypokalemia resolved spontaneously within 24 hours. All patients recovered without neurological sequalae. Transient hypokalemia frequently occurs in children even with minor head trauma. This hypokalemia resolves spontaneously, without treatment and within 24 hours.