Clinical Question: Is seizure prophylaxis necessary in children experiencing moderate to severe blunt head injury?

Setting: Emergency department

Study Design: Randomized controlled trial (double-blinded)

Synopsis: Investigators enrolled 102 children younger than 16 years who had experienced an acute blunt head injury with a marked alteration in level of consciousness (i.e., Glasgow Coma Scale score of less than 10 out of 15 in children four years or older or Children’s Coma Scale score of less than nine out of 11 in children younger than four years). Children who already had a seizure before presenting to the emergency department were not enrolled. The children were randomized (allocation concealed) to receive placebo or phenytoin in a dosage of 18 mg per kg initially, and then 2 mg per kg every eight hours for 48 hours.

During the observation period of up to 48 hours, seizures occurred in 7 percent of children receiving phenytoin and 5 percent of children receiving placebo. At the time of the seizure, phenytoin levels were therapeutic in the treated children. Seizures occurred in two of the children who survived to 30 days after the observation period. The study required significantly more children to find a difference, if one truly exists, especially given the low frequency of seizures.

Bottom Line: Children with acute head injury who do not experience an immediate seizure do not benefit from seizure prophylaxis. In this study, there was a low rate of seizure (7 percent in the treated children and 5 percent in the children receiving placebo) in the 48 hours following those patients’ arrival in the emergency department. Given the low number of seizures, it is possible that there is an effect that was not found in this study. (Level of Evidence: 1b)