Magnesium sulfate in severe perinatal asphyxia: a randomized, placebo-controlled trial.

OBJECTIVE The goal was to study whether postnatal magnesium sulfate infusion could improve neurologic outcomes at discharge for term neonates with severe perinatal asphyxia. METHODS Forty term (> or =37 weeks of gestation) neonates with severe perinatal asphyxia were studied in a prospective, longitudinal, placebo-controlled trial. Patients were assigned randomly to receive either 3 doses of magnesium sulfate infusion at 250 mg/kg per dose (1 mL/kg per dose) 24 hours apart (treatment group) or 3 doses of normal saline infusion (1 mL/kg per dose) 24 hours apart (placebo group). Both groups also received supportive care according to the unit protocol for perinatal asphyxia. RESULTS In the treatment group, moderate encephalopathy was present in 35% (7 of 20) of the patients and severe encephalopathy in 65% (13 of 20) of patients at admission. In the placebo group, 40% (8 of 20) of patients had moderate encephalopathy and 60% (12 of 20) of patients had severe encephalopathy. The mean serum magnesium concentration in the treatment group remained at > or =1.2 mmol/L for 72 hours after the first infusion. At discharge, 22% (4 of 18) of infants in the treatment group had neurologic abnormalities, compared with 56% (10 of 18) of infants in the placebo group. Also, neuroimaging (head computed tomography) performed on day 14 yielded abnormal findings for fewer infants in the treatment group than in the placebo group (16% vs 44%). Infants in the treatment group were more likely to be receiving oral feedings (sucking) at discharge than were those in the placebo group (77% vs 37%). Good short-term outcomes at discharge occurred for 77% of the patients in the treatment group, compared with 37% of the patients in the placebo group. CONCLUSION Postnatal magnesium sulfate treatment improves neurologic outcomes at discharge for term neonates with severe perinatal asphyxia.