Physiological Disturbances Associated With Neonatal Intraventricular Hemorrhage

Annually, almost 5,000 extremely low birth weight (9 ounces to about 2 lbs) infants born in
the US survive with severe bleeding in the brain (intraventricular hemorrhage); this
devastating complication of prematurity is associated with many problems, including mental
retardation, cerebral palsy, and learning disabilities, that result in profound individual
and familial consequences. In addition, lifetime care costs for these severely affected
infants born in a single year exceed $3 billion. The huge individual and societal costs
underscore the need for developing care strategies that may limit severe bleeding in the
brain of these tiny infants. The overall goal of our research is to evaluate disturbances of
brain blood flow in these tiny infants in order to predict which of them are at highest risk
and to develop better intensive care techniques that will limit severe brain injury.

1. Since most of these infants require ventilators (respirators) to survive, we will
investigate how 2 different methods of ventilation affect brain injury. We believe that
a new method of ventilation, allowing normal carbon dioxide levels, will normalize
brain blood flow and lead to less bleeding in the brain.

2. We will also examine how treatment for low blood pressure in these infants may be
associated with brain injury. We believe that most very premature infants with low
blood pressure actually do worse if they are treated. We think that by allowing the
infants to normalize blood pressure on their own will allow them to stabilize blood
flow to the brain leading to less intraventricular hemorrhage.

3. In 10 premature infants with severe brain bleeding, we have developed a simple
technique to identify intraventricular hemorrhage before it happens. Apparently, the
heart rate of infants who eventually develop severe intraventricular hemorrhage is less
variable than infants who do not develop this. We plan to test this method in a large
group of infants, to be able to predict which infants are at highest risk of developing
intraventricular hemorrhage and who could most benefit from interventions that would
reduce disturbances of brain blood flow.