Seizure from hyponatremia in infants. Early recognition and treatment.

OBJECTIVES

To determine whether history, vital signs, and physical examination may be used as predictors of hyponatremia in first-time seizure in infancy; to examine the efficacy and safety of 3% saline bolus administered to control seizures; and to determine whether early intervention reduces apnea-related complications.

DESIGN

Retrospective case series comparing clinical characteristics and initial laboratory data of infants with hyponatremic seizures and seizures of other categories. Treatment strategies and outcomes are examined in hyponatremic infants to determine the efficacy and safety of 3% saline administration.

SETTING

Tertiary care community medical center.

PARTICIPANTS

Fifty-six consecutive infants under 1 year of age with first-time seizure.

RESULTS

Fifteen infants (27%) had hyponatremic seizure. They were younger and had lower body temperatures, higher serum glucose concentrations, and lower serum bicarbonate concentrations than infants with nonhyponatremic seizure (P < .05). All infants with hyponatremic seizure were formula fed; 13 (87%) had excessive solute-poor fluid. Hyponatremic seizures were more difficult to control and required more frequent intubation. Three of seven hyponatremic infants treated early with 3% saline required intubation. Six of eight infants who received delayed 3% saline solution or none required intubation. No adverse effects resulted from administration of hypertonic saline.

CONCLUSION

Parameters for recognizing hyponatremic seizure include age less than 6 months; formula with solute-poor fluid; absence of significant medical history or recent febrile illness, hypothermia, hyperglycemia, status epilepticus, and absence of evidence of trauma. Bolus 3% saline was safe and effective in controlling hyponatremic seizure; early use reduced morbidity from anticonvulsant therapy.