Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Neurological impairment
Systematic review	77 surviving term infants 3 RCTs in this analysis	Rates of severe neurodevelopmental disability 9/40 (23%) with barbiturate (thiopental or phenobarbital) 14/37 (38%) with no drug treatment	RR 0.61 95% CI 0.30 to 1.22		Not significant
RCT	45 asphyxiated neonates (gestational age 34 weeks and over) manifesting hypoxic–ischaemic encephalopathy in the first 6 hours of life	Proportion of infants who developed seizures 2/25 (8%) with prophylactic phenobarbital (20 mg/kg given within 6 hours after birth) 8/20 (40%) with standard treatment	RR 0.20 95% CI 0.05 to 0.84 NNT 3.1 95% CI 1.8 to 12.5	Moderate effect size	phenobarbital