Magnesium useful for newborns with low oxygen
NEW YORK (Reuters Health) - Early treatment with magnesium can reduce the nerve damage seen in infants with low oxygen levels, also referred to as asphyxia at birth, according to a trial conducted in India and published in the journal Pediatrics.
Perinatal asphyxia occurs when a newborn is deprived of oxygen long enough to cause apparent damage. Most commonly, it is due to a fall in the mother's blood pressure or interference during delivery with blood flow to the infant's brain. Between 2 and 10 infants per 1000 born at full-term will have perinatal asphyxia.
Asphyxia causes high levels of the animo acid glutamate to build up in the newborn brain, explain Dr. Mushtaq Ahmad Bhat and co-investigators at the Sheri-Kashmir Institute of Medical Sciences in Srinagar. For up to 72 hours, the excess glutamate causes irreversible nerve injury by opening certain cell channels and allowing calcium to flow into cells. Magnesium works to block this calcium inflow.
The researchers' trial included 40 term infants admitted to their neonatal intensive care unit with severe perinatal asphyxia and moderate or severe brain injury. They were randomly assigned to receive three magnesium treatments or inactive placebo.
Both groups received their assigned treatment within 6 hours of birth, then again after 24 and 48 hours. All patients also received normal supportive care for perinatal asphyxia. Two patients in each group died during hospitalization.
Fifty-six percent of patients given placebo had abnormal neurologic exams when discharged from the hospital compared with just 22 percent of those given magnesium.
This study is the first one with a placebo comparison group to show "improved neurologic outcomes at discharge in the magnesium...group," the authors note.
They caution that two patients on magnesium developed temporary breathing loss requiring use of a respiratory, "which confirms that adverse effects can occur during (magnesium use) and intense monitoring is needed."
They conclude that large, multicenter trials are now needed to corroborate their findings.
SOURCE: Pediatrics, May 2009.